Analytical methods cited in the Astromat database. The database currently contains a compilation of data acquired from meteorites and lunar samples returned by the Apollo missions. The Astromaterials Data System (Astromat, https://www.astromat.org/about/overview/) is a comprehensive data infrastructure to access, publish, and preserve laboratory analytical data generated on astromaterials samples. Astromat aims to ensure the long-term value of astromaterials samples data and maximize their impact on scientific discovery and knowledge.
Astromaterials Data System (Astromat)
GEOROC (https://georoc.eu/) is a comprehensive collection of published analyses of igneous and metamorphic rocks and minerals. It contains major and trace element concentrations, radiogenic and nonradiogenic isotope ratios as well as analytical ages for whole rocks, glasses, minerals and inclusions. Metadata include geospatial and other sample information, analytical details and references. Digital Geochemical Data Infrastructure (DIGIS) will continue and enhance GEOROC, originally curated by the Max Planck Institute for Chemistry. Labels for analytical methods from GEOROC were compiled by Marthe Klocking, University of Gottingen, Germany, and in collaboration with Annika Johansson (IEDA, Lamont Doherty Earth Observatory, see PetDB agent) mapped to labels for techniques from PetDB; the compilation included definitions that were reviewed and enhances in some cased in this vocabulary.
Geochemistry of Rocks of the Oceans and Continents (GEOROC)
vocabulary contributed by Manja Luzi, editor, under the auspices of the Research Network for Geosciences in Berlin and Potsdam (Geo.X, https://www.geo-x.net/en/), vocabulary used for information managment at Geo.X. Sources include NASA Global Change Master Directory (GCMD), 2021, GCMD Keywords, Version 11.1, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA). GCMD Keyword Forum Page https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords; German Research Foundation, 2021, Instrumentation category key. URL: https://www.dfg.de/en/research_funding/programmes/infrastructure/scientific_instrumentation/category_key/index.html (Downloadable versions of the instrumentation category key are provided in German only.); IUPAC (International Union of Pure and Applied Chemistry): Compendium of Analytical Terminology, current project title: Vocabulary of Concepts and Terms in Analytical Chemistry - the revised Orange Book. 4th edition: Royal Society of Chemistry, 2021. URL: https://iupac.org/project/2012-005-1-500; U.S. Geological Survey, 2021, USGS Thesaurus. URL: https://apps.usgs.gov/thesaurus/thesaurus-full.php?thcode=2; EarthChem Library, 2021, Geochemistry Data Templates. URL: https://www.earthchem.org/ecl/templates/; Georef Thesaurus. Edited by Barbara A. Goodman. 11th edition: American Geological Institute, 2008. URL: https://www.americangeosciences.org/information/georef/thesaurus/lists
Analytical methods requested based on metbase data. Metbase is a compilation of meteorite data published between 1492 and today, built by scientists for scientists and released exclusively online. More than 500,000 data of meteorite analyses are stored in MetBase, including Bulk chemical compositions, Major/minor/trace elements in iron meteorites, Mineral chemistry, Cosmogenic radionuclides, Light stable isotopes, Noble gas isotopes, TL data, porosities, and densities.
Meteorite Information Database (Metbase)
Analytical methods planned for the investigation of sample material returned from asteroid Bennu by the OSIRIS-REx mission (https://www.asteroidmission.org/). Some method descriptions that only have orex listed as source are from the O-REx Confluence web content. The mission sample analysis team has been compiling descriptions of analytical techniques planned, and the dictionary of planned methods has been shared with Astromat data managers and been made available for this compilation. (https://curation.isas.jaxa.jp/symposium/abstract/2021/S6-2_Connolly.pdf)
OSIRIS-REx Sample Analysis Team
Methods compiled from PetDB database by Annika Johansson and mapped to GEOROC and Astromat method labels. PetDB is an integrated data synthesis through which you can access chemical, isotopic, and mineralogical data from peer-reviewed literature. (https://www.earthchem.org/resources/support/petdb-documentation/)
Accelerator mass spectrometry
In this technique, the target element is first chemically separated from the sample before it is placed in a sample holder in the AMS instrument. The sample element is then bombarded by cesium ions to sputter the analyte element from the sample as negative ions. The analyte ions are then accelerated down a beam tube by a positive potential difference of several million volts, passed through an electron stripper to convert them to positive ions, and accelerated back down the beam tube toward common potential where ion velocities approach a few percent of the speed of light. Using a series of magnetic and electrostatic mass filters, the ion beam containing all isotopes of the analyte element is then separated into separate beams containing the (usually unstable) isotope of interest and other isotopes, and each of the isotopes is counted by a separate detector. (Skoog, Holler & Crouch, p. 271). Components: 1) sample preparation: chemical concentration of analyte; 2) ionization: ion beam; 3) mass analyzer: accelerator Mass spectrometer; 4) detector: not specified.
Acid reaction carbonate analysis
Determination of calcium carbonate content by reaction with an acid and determining the quantity of CO2 produced. Different techniques use different acids and CO2 production measurement approaches.
Adsorption analysis
ADSORPTION
The gas adsorption technique may used to measure the specific surface area and pore size distribution of powdered or solid materials. The dry sample is usually evacuated of all gas and cooled to a temperature of 77K, the temperature of liquid nitrogen. At this temperature inert gases such as nitrogen, argon and krypton will physically adsorb on the surface of the sample. This adsorption process can be considered to be a reversible condensation or layering of molecules on the sample surface during which heat is evolved. Nitrogen gas is ideal for measuring surface area and pore size distribution. (http://www.cyto.purdue.edu/cdroms/cyto2/6/coulter/ss000107.htm)
AFM topography imaging
a sharp probe tip mounted on a microcantilever scans over the specimen line by line, whereby the topographic image of the sample surface is generated by 'feeling' rather than 'looking.' (https://doi.org/10.1007/978-3-642-16712-6_496). As the tip approaches the surface, the close-range, attractive forces between the surface and the tip causes the cantilever to deflect towards the surface. However, as the cantilever is brought even closer to the surface, until the tip makes contact with it, increasingly repulsive forces takes over and causes the cantilever to deflect away from the surface. (https://lnf-wiki.eecs.umich.edu/wiki/Atomic_force_microscopy)
Alpha particle counting
ALPHA COUNTING ISOTOPE DILUTION
ALPHA COUNTING
ALPHA PARTICLE DECAY COUNTING
ALPHA-DECAY COUNTING
The count rate of alpha particles emitted form the surface of a sample; used to assess concentration of U, Th, other radiogenic elements
Alpha particle spectrometry
Alpha spectrometry
ISOTOPE-DILUTION ALPHA-SPECTROMETRY
Analysis of the energy of alpha particles emitted by a radioactive nuclide that is an alpha emitter. As emitted alpha particles are mono-energetic (i.e. not emitted with a spectrum of energies, such as beta decay) with energies often distinct to the decay they can be used to identify which radionuclide they originated from. (https://en.wikipedia.org/wiki/Alpha-particle_spectroscopy)
Alpha recoil track counting
ALPHA-RECOIL TRACKS DATING
Like fission-track dating, alpha-recoil track (ART) dating is based on the accumulation of nuclear particles that are released by natural radioactivity and produce etchable tracks in solids. ARTs are formed during the alpha-decay of uranium and thorium as well as of their daughter nuclei. When emitting an alpha-particle, the heavy remaining nucleus recoils 30-40 nm, leaving behind a trail of radiation damage. Through etching the ART tracks become visible with interference phase-contrast microscopy. Alpha-recoil dating has a great potential for Quaternary chronometry and tephrochronology. (https://doi.org/10.1016/S0009-2541(99)00185-0)
Amperometry
Technique based on measurement of current at a controlled applied potential. Application: monitoring of carbon monoxide in air, dissolved oxygen in water (Clark electrode), glucose in blood (glucose electrode). (Source: IUPAC; https://doi.org/10.1515/pac-2018-0109).
Analytical method
Analytical technique
Other
UNKNOWN
Procedures that operate on material samples to produce observation results with information about the physical properties, chemical or isotopic composition, crystallography, or molecular structure of the sample.
Angle of repose measurement
A granular sample is poured to create a cone or slope at the maximum angle of stability. This slope could be directly measured with a angle tool, or better yet should be analyzed from a 3d reconstruction of the scene. Various techniques might be used to reconstruct the shape of the cone.
Anion chromatography analysis
ANION CHROMATOGRAPHY
Anion-exchange chromatography is when the stationary phase is positively charged and negatively charged molecules are loaded to be attracted to it. (https://en.wikipedia.org/wiki/Ion_chromatography)
Atomic absorption spectrometry
ATOMIC ABSORPTION
Atomic absorption spectrophotometry
Atomic absorption spectroscopy
MICROABSORPTION ANALYSIS
MICROABSORPTION
Analytical technique used to measure a wide range of elements in materials such as metals, pottery and glass, based on absorption of light by free metallic ions. The sample is accurately weighed and then dissolved, often using strong acids. The resulting solution is sprayed into the flame of the instrument and atomized. Light of a suitable wavelength for a particular element is shone through the flame, and some of this light is absorbed by the atoms of the sample. Individual elements will absorb wavelengths differently, and these absorbances are measured against standards. The amount of light absorbed is proportional to the concentration of the element in the solution, and hence in the original object. Measurements are made separately for each element of interest in turn to achieve a complete analysis of an object, and thus the technique is relatively slow to use. However, it is very sensitive and it can measure trace elements down to the part per million level, as well as being able to measure elements present in minor and major amounts. The method requires standards with known analyte content to establish the relation between the measured absorbance and the analyte concentration. (https://en.wikipedia.org/wiki/Atomic_absorption_spectroscopy; (https://www.thermofisher.com/us/en/home/industrial/spectroscopy-elemental-isotope-analysis/spectroscopy-elemental-isotope-analysis-learning-center/trace-elemental-analysis-tea-information/atomic-absorption-aa-information.html)). Although it is a destructive technique (unlike ED-XRF), the sample size needed is very small (typically about 10 milligrams - i.e. one hundredth of a gram) and its removal causes little damage. Additional information available at http://www.thebritishmuseum.ac.uk/science/text/techniques/sr-tech-aas-t.html
Atomic force microscopy
a high-resolution, non-optical imaging technique that uses a cantilever with a sharp tip to scan over a sample surface. AFM can be used to image almost any type of surface, including polymers, ceramics, composites, glass, and biological samples. AFM can also be used to measure and localize many different forces, including adhesion strength, magnetic forces, and mechanical properties.
Atom probe tomography
To conduct an atom probe experiment a very sharp needle shaped specimen is placed in an ultra high vacuum chamber. After introduction into the vacuum system, the sample is reduced to cryogenic temperatures (typically 20-100 K) and manipulated such that the needle's point is aimed towards an ion detector. A high voltage is applied to the specimen, and either a laser pulse is applied to the specimen or a voltage pulse (typically 1-2 kV) with pulse repetition rates in the hundreds of kilohertz range is applied to a counter electrode. The application of the pulse to the sample allows for individual atoms at the sample surface to be ejected as an ion from the sample surface at a known time. Typically the pulse amplitude and the high voltage on the specimen are computer controlled to encourage only one atom to ionize at a time, but multiple ionizations are possible. The delay between application of the pulse and detection of the ion(s) at the detector allow for the computation of a mass-to-charge ratio. The method is destructive in nature removing ions from a sample surface in order to image and identify them, generating magnifications sufficient to observe individual atoms as they are removed from the sample surface. Through coupling of this magnification method with time of flight mass spectrometry, ions evaporated by application of electric pulses can have their mass-to-charge ratio computed. Through successive evaporation of material, layers of atoms are removed from a specimen, allowing for probing not only of the surface, but also through the material itself.The instrument allows the three-dimensional reconstruction of up to billions of atoms from a sharp tip (corresponding to specimen volumes of 10,000-10,000,000 nm3). (https://en.wikipedia.org/wiki/Atom_probe)
Auger electron spectroscopy
a form of electron spectroscopy that relies on the Auger effect, based on the analysis of energetic electrons emitted from an excited atom after a series of internal relaxation events.Surface sensitivity in Auger electron spectroscopy (AES) arises from the fact that emitted electrons usually have energies ranging from 50 eV to 3 keV and at these values, electrons have a short mean free path in a solid. The escape depth of electrons is therefore localized to within a few nanometers of the target surface, giving AES an extreme sensitivity to surface species (https://en.wikipedia.org/wiki/Auger_electron_spectroscopy)
Backscattered electron grain boundary imaging
Image showing grain boundaries generated by detecting crytallographic orientation changes in a raster of backscattered electron diffraction data points.
Backscattered electron imaging
Backscatter electron microscopy
Techniques that involve bombarding a sample with an accelerated electron beam to produce backscattered electrons. An image is formed by scanning the beam in a raster across the sample surface and measuring the intensity (count?) of backscattered electrons at each sample point. BSEs are reflected back after elastic interactions between the beam and the sample. BSE images show high sensitivity to differences in atomic number; the higher the atomic number, the brighter the material appears in the image. (https://www.thermofisher.com/blog/materials/sem-signal-types-electrons-and-the-information-they-provide/)
Bench chemistry
Analytical techniques performed by an analyst mixing and handling chemicals directly, not employing any of the high-tech devices or theoretical approaches that may be associated with the most state-of-the-art aspects of the discipline.
Beta counting
detection and quantification of beta-emitting radioactive material. Beta counters are used to characterize the decay of short-lived radionuclides.
Bioanalytical method
Analytical technique to determine biochemical properties of samples from living organisms, particularly related to genomics or 'omics in general.
This section is very incomplete; techniques that occur in source repository data are included, but this is mostly a hook for a more comple vocabulary of bioanalytical methods, out of scope at this time 2023-03-14.
Broad beam X-ray spectrometry
BROAD BEAM ANALYSIS
Technique to induce X-ray emission using a broad (large diameter) ion or electron beam as the excitation. [inferred from https://inis.iaea.org/collection/NCLCollectionStore/_Public/30/060/30060365.pdf, but not really clear what is meant here...]
Capacitance dilatometry
Measurement of the linear coefficient of thermal expansion in a solid material, using a parallel plate capacitor with a one stationary plate, and one moveable plate. When the sample length changes, it moves the moveable plate, which changes the gap between the plates. The capacitance is inversely proportional to the gap. Changes in length of 10 picometres can be detected. (https://en.wikipedia.org/wiki/Dilatometer)
Carbonate bomb analysis
CARBONATE BOMB
Treatment of a sample with HCl in a closed instrument creates CO2 pressure porportional to the CaCO3 content of the sample (Muller and Gastner, 1971, https://epic.awi.de/id/eprint/27239/1/Mll1971a.pdf)
Catalytic combustion analysis
[might be:] The 680 degree C combustion catalytic oxidation method achieves total combustion of samples by heating them to 680 degree C in an oxygen-rich environment inside TC combustion tubes filled with a platinum catalyst. Since this utilizes the simple principle of oxidation through heating and combustion, pretreatment and post-treatment using oxidizing agents are unnecessary, which enhances operability. The carbon dioxide generated by oxidation is detected using an infrared gas analyzer (NDIR). (https://www.shimadzu.eu.com/680-%C2%B0c-combustion-catalytic-oxidation-method-measurement-principles; https://www.sciencedirect.com/science/article/abs/pii/0304420388900436)
Cathodoluminescence imaging
High resolution cathodoluminescence
In a vacuum chamber containing the sample of interest, an electron beam is focused on the sample, causing cathodoluminescence (CL), the generation of electromagnetic radiation ranging from the ultraviolet (UV) to the near-infrared (NIR) regime of the electromagnetic spectrum. The light is collected with a collection optic (e.g. mirror or objective) and directed to a light detection unit, or directly captured by a detector in the chamber. This detector output is used to characterize various aspects of the light signal such as its intensity, color, and more. Many trace elements or dopants can be sensitively detected with CL because they have different optical transitions than the bulk materials they are embedded in. It is possible to look at crystal defects as these can alter the local optical properties of the material. CL can also image optical resonances and guided modes in a range of (resonant) photonic and plasmonic systems. (https://www.delmic.com/en/techniques/cathodoluminescence)
Cation chromatography analysis
Cation Chromatography
Cation-exchange chromatography is used when the molecule of interest is positively charged. The molecule is positively charged because the pH for chromatography is less than the pI (a/k/a pH(I)). In this type of chromatography, the stationary phase is negatively charged and positively charged molecules are loaded to be attracted to it. (https://en.wikipedia.org/wiki/Ion_chromatography)
Cavity enhanced absorption spectrometry
technique to increase sensitivity of laser absorption spectrometry by placing analyzed gas in a cavity with mirrors such that the light bounces back and forth, increasing the interaction length between the light and the sample.
Cavity ring-down spectrometry
In CRDS, the beam from a single-frequency laser diode enters a cavity defined by two or more high reflectivity mirrors. When the laser is on, the cavity quickly fills with circulating laser light. A fast photodetector senses the small amount of light leaking through one of the mirrors to produce a signal that is directly proportional to the intensity in the cavity. When the photodetector signal reaches a threshold level (in a few tens of microseconds), the continuous wave (CW) laser is abruptly turned off. The light already within the cavity continues to bounce between the mirrors (about 100,000 times), but because the mirrors have slightly less than 100% reflectivity (99.999%), the light intensity inside the cavity steadily leaks out and decays to zero in an exponential fashion. This decay, or "ring down", is measured in real-time by the photodetector, and the amount of time it takes for the ring down to happen is determined solely by the reflectivity of the mirrors (for an empty cavity). When a gas species that absorbs the laser light is introduced into the cavity, a second loss mechanism (absorption) is introduced, which accelerates the ring down time. Analysis of the ring down time of the cavity with and without absorption due to the target gas species can be used to calculate the concentration of the absorbing substance in the gas mixture in the cavity. Comparison of the ring down time of the cavity with and without any absorbing gas is accomplished by tuning the laser first to a wavelength where the gas absorbs light, and then to a wavelength where the gas does not absorb light.
Charmograph analysis
CHARMOGRAPH
Carbonate was determined with a Charmograph 6 (Wosthoff). The sample was heated in 2 N phosphoric acid and the released carbon dioxide passed through a 0.05 N sodium hydroxide solution. Carbonate concentrations were calculated from the conductivity changes of the sodium hydroxide solution (https://drs.nio.org/drs/bitstream/handle/2264/7525/J_Geophys_Res_C_101_28569.pdf)
Chromatography analysis
a laboratory technique for the separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the mobile phase, which carries it through a system (a column, a capillary tube, a plate, or a sheet) on which a material called the stationary phase is fixed. The different constituents of the mixture travel at different apparent velocities in the mobile fluid, causing them to separate. The separation is based on the differential partitioning between the mobile and the stationary phases. The purpose of chromatography analysis is to establish the presence or measure the relative proportions of analytes in a mixture. The result is a chromatogram (https://en.wikipedia.org/wiki/Chromatography)
Colormetric analysis
COLORIMETRIC ANALYSIS
COLORIMETRY
A method of chemical analysis in which reagents are added to a solution to form coloured compounds with specific elements. The intensity of the colour, measured on a spectrophotometer, is proportional to the concentration of the element. ('colorimetric analysis .' A Dictionary of Earth Sciences. Encyclopedia.com. 21 Dec. 2022 <https://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/colorimetric-analysis>.)
Combustion analysis
COMBUSTION
TOTAL COMBUSTION ANALYSIS
TOTAL COMBUSTION
Technique for determination of empirical and molecular formulas for compounds that contain only carbon and hydrogen or carbon, hydrogen, and oxygen. The steps for this procedure are: 1) Weigh a sample of the compound to be analyzed; 2) Burn the compound completely. 3) H2O and CO2 are drawn through two tubes. One tube contains a substance that absorbs water, and the other contains a substance that absorbs carbon dioxide. Weigh each of these tubes before and after the combustion. The increase in mass in the first tube is the mass of H2O that formed in the combustion, and the increase in mass for the second tube is the mass of CO2 formed. Assume that all the carbon in the compound has been converted to CO2 and trapped in the second tube. Calculate the mass of carbon in the compound from the mass of carbon in the measured mass of CO2 formed. Assume that all of the hydrogen in the compound has been converted to H2O and trapped in the first tube. Calculate the mass of hydrogen in the compound from the mass of hydrogen in the measured mass of water. If the compound contains oxygen as well as carbon and hydrogen, calculate the mass of the oxygen by subtracting the mass of carbon and hydrogen from the total mass of the original sample of compound. (https://preparatorychemistry.com/Bishop_Combustion_Analysis.htm)
Combustion gas chromatography
Method in which an analytical sample is decomposed by heating in an oxygen atmosphere to induce combustion, and analyzing the combustion products by gas chromatography
Combustion gas chromatography isotopic ratio mass spectrometry
Technique used to ascertain the relative ratio of light stable isotopes of carbon (13C/12C), hydrogen (2H/1H), nitrogen (15N/14N) or oxygen (18O/160) in individual compounds separated from often complex mixtures of components. The sample solution is injected into the gas chromatography (GC) inlet where it is vaporized and swept onto a chromatographic column by the carrier gas (usually helium). The sample flows through the column and the compounds comprising the mixture of interest are separated by virtue of their relative interaction with the coating of the column (stationary phase) and the carrier gas (mobile phase). Carbon and nitrogen compounds eluting from the chromatographic column then pass through a combustion reactor (an alumina tube containing Cu, Ni and Pt wires maintained at 940 degree C) where they are oxidatively combusted. This is followed by a reduction reactor (an alumina tube containing three Cu wires maintained at 600 degree C) to reduce any nitrogen oxides to nitrogen. For hydrogen and oxygen a high temperature thermal conversion reactor is required. Water is then removed in a water separator by passing the gas stream through a tube constructed from a water permeable nafion membrane. The sample is then introduced into the ion source of the mass analyzer by an open split interface, and particles with m/z ratios of interest are counted by detectors.
Combustion infrared spectrometry
COMBUSTION-INFRARED ANALYSIS
COMBUSTION-INFRARED TECHNIQUE
Composite process, with combustion of sample and infrared spectrographic analysis of constituents. [Need more information -- ?emission or absorption?, is light from the combution analyzed, or does it produce an extract that is then passed to the spectrometer? ]
Combustion Ion Chromatography
Samples are pyrolyzed in an oxidizing atmosphere, the resultant vapors are absorbed in an aqueous solution, then introduced directly into an ion chromatography system for analysis.
Compression test
Uniaxial squeezing a single mm to sub-mm sample particle between two rigid metallic pistons for quantitative determination of mechanical properties (elastic modulus, crushing strength, critical flaw length at failure, and fracture behavior).
Confocal X-ray fluorescence spectrometry
The confocal geometry uses two polycapillary focusing optics for enhanced applications of XRF elemental analysis. An excitation optic focuses a small X-ray beam onto the specimen. A detection optic collects fluorescent X-rays from the sample. Specifically, elemental concentrations are measured within the small probe volume ('confocal volume') defined by the intersection of the output focal spot of the excitation optic and the input focal spot of the collection optic. The polycapillary focusing optics act as spatial filters to eliminate background radiation from the sample and increase detection sensitivity for sample elements of interest. Additionally, confocal XRF can be used for elemental depth profiling. Confocal XRF acts as a material probe by exciting and detecting emitted characteristic X-ray photons from within the confocal analysis volume as this volume is through the sample. In this way elemental concentrations can be measured on the object's surface and throughout the object's interior. (https://www.xos.com/Confocal-XRF)
Continuous flow isotope ratio mass spectrometry
ELEMENTAL ANALYSER CONTINUOUS FLOW ISOTOPIC RATIO MASS SPECTROMETER
ELEMENTAL ANALYZER CONTINUOUS-FLOW ISOTOPE RATIO MASS SPECTROMETRY
Isotope-Ratio mass spectrometry that extracts analytes from a sample using elemental analyzer with a contintuous flow of gas to be atomized, ionized and passed to the mass analyzer. Components: 1) elemental analyzer; 2) continuous flow input. 3) mass analyzer 4) detectors. Analyzed aliquots are gas.
Coulometrical analysis
Coulometry uses either an applied current or potential to exhaustively convert an analyte from one oxidation state to another at the working electrode. In these experiments, the total current passed is measured directly or indirectly to determine the number of electrons passed. Knowing the number of electrons passed, extract the concentration of the analyte (Timothee Houssin, ... Vincent Senez, in Waterborne Pathogens (Second Edition), 2021)
Desorption electrospray ionization orbitrap mass spectrometry
technique in which sample ionization is achieved by a process in which a spray of charged droplets is directed towards the sample. When the spray impacts the sample, a thin layer of solvent is formed into which the analytes may dissolve. As other primary droplets arrive at the sample surface, they splash secondary microdroplets containing the dissolved analytes from the solvent film. This mechanism causes analyte-containing droplets to be generated in the open air, and then delivered to the mass spectrometer through a heated extended capillary. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3205348). After the desorption process, ionization occurs via mechanisms that are similar to those of electrospray ionization, in which a high voltage is applied to a liquid to create an aerosol (https://en.wikipedia.org/wiki/Electrospray_ionization). Mass analysis is done with an Orbitrap mass analyzer. (https://en.wikipedia.org/wiki/Orbitrap)
Deuteron activation analysis
irradiate sample with deuterons, measure gamma ray spectrum (https://doi.org/10.1007/BF02520983). Deuterons are nuclei of deuterium atoms, consisting of a proton and a neutron.
Dietrich-Fruhling calcimetry
DIETRICH-FRUHLING CALCIMETER
Instrument consisting of a sample-holder, one serpentine for cooling and one graduated cylinder with readings on the result of reaction between calcium carbonate and diluted chloridric acid. Since the volume of CO2 (carbonic anhydride) is in relationship with CaCO2 (carbonate contained in the material) it shall be possible to calculate the percentage of CaCO3. (https://www.gabbrielli.com/en/prodotto/dietrich-fruhling-calcimeter/)
Differential scanning calorimetry
Heat-flow DSC
Power compensation DSC
Technique where either the difference between heat flow rates into a sample and a reference material is measured (heat-flow DSC) or the difference between the electrical powers into a sample and a reference material is measured (power compensation DSC). (Source: IUPAC; https://doi.org/10.1515/pac-2012-0609). A technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature. Both the sample and reference are maintained at nearly the same temperature throughout the experiment. Generally, the temperature program for a DSC analysis is designed such that the sample holder temperature increases linearly as a function of time. The reference sample should have a well-defined heat capacity over the range of temperatures to be scanned. By observing the difference in heat flow between the sample and reference, differential scanning calorimeters are able to measure the amount of heat absorbed or released during phase transitions. DSC may also be used to observe more subtle physical changes, such as glass transitions. It is widely used in industrial settings as a quality control instrument due to its applicability in evaluating sample purity and for studying polymer curing. (https://en.wikipedia.org/wiki/Differential_scanning_calorimetry)
Differential thermal analysis
Differential analyzer
Differential thermal analysis (DTA) is a technique in which the material under study and an inert reference are made to undergo identical thermal cycles, (i.e., same cooling or heating programme) while recording any temperature difference between sample and reference. This differential temperature is then plotted against time, or against temperature (DTA curve, or thermogram). Changes in the sample, either exothermic or endothermic, can be detected relative to the inert reference. Thus, a DTA curve provides data on the transformations that have occurred, such as glass transitions, crystallization, melting and sublimation. The area under a DTA peak is the enthalpy change and is not affected by the heat capacity of the sample. DTA is similar to differential scanning calorimetry.
GEOROC groups 'THERMOGRAVIMETRIC AND DIFFERENTIAL ANALYZER' as one technique, split into two techniques in this vocabulary.
Direct current plasma emission spectrometry
DIRECT-CURRENT PLASMA ATOMIC EMISSION SPECTROMETRY
A type of atomic emission spectrometry where a plasma generated by passing an electrical discharge between two electrodes is used as the excitation source. (https://www.rsc.org/publishing/journals/prospect/ontology.asp?id=CMO:0000265&MSID=b200027j)
Direct current plasma spectrometry
DIRECT CURRENT PLASMA (FURTHER DETAIL NOT PROVIDED)
DIRECT-CURRENT PLASMA SPECTROMETRY
A type of spectrometry where a plasma generated by passing an electrical discharge between two electrodes is used as the excitation source. Could be absorption, emission or transmission spectral analysis.
Direct shear strength measurement
A shear stress is applied to a cubic sample until it fails (subdivides) by shear fracturing. The ultimate shear strength of the sample is determined from the peak of the resulting shear stress versus shear displacement curve
DNA sequencing
Determination of nucleotide sequence (the DNA primary structure). (Source: IUPAC; https://doi.org/10.1515/iupac.90.0262, https://www.degruyter.com/database/IUPAC/entry/iupac.90.0262/html)
Dual inlet isotope ratio mass spectrometry
Mass spectrometry technique. Components: 1) sample preparation, extract gas, purify; 2) ionization: not specified. Isotope-Ratio mass spectrometry that uses dual inputs to compare and calibrate sample measurement. In dual inlet IRMS, purified gas obtained from a sample is alternated rapidly with a standard gas (of known isotopic composition) by means of a system of valves, so that a number of comparison measurements are made of both gases. (https://en.wikipedia.org/wiki/Isotope-ratio_mass_spectrometry). Analyzed aliquots are gas.
Electrical conductivity measurement
Methods used to measure the electrical conductivity of a sample in an electrochemistry cell.
Electrochemical impedance spectroscopy
IMPEDANCE ELECTROCHEMICAL SPECTROSCOPY
tool to investigate properties of materials and electrode reactions. the response of the system (ionic solution and electrodes) to a potential or current sinusoidal perturbation is studied as a function of the frequency, which is swept over a few decades. The frequency sweep enables access to all processes taking place at the electrode: charge transfer and mass transport. Any other electrical contribution and artefacts are visible with EIS. (https://www.biologic.net/topics/what-is-eis/). Electrochemical impedance is the response of an electrochemical system (cell) to an applied potential. The frequency dependence of this impedance can reveal underlying chemical processes. (https://www.jlab.org/conferences/tfsrf/Thursday/Th2_1-EIS%20intro%20Reece.pdf)
Electrochemical techniques
Techniques that use electron movement in an oxidation or reduction reaction at a polarized electrode surface to determine chemical properties of an analyte. Each analyte is oxidized or reduced at a specific potential and the current measured is proportional to concentration. Electrochemistry is widely used for measurement of a wide range of analytes. (Bhavik A. Patel, in Electrochemistry for Bioanalysis, 2020)
Electron backscatter diffraction
a flat/polished crystalline specimen is placed in the SEM chamber at a highly tilted angle (~70degree from horizontal) towards the diffraction camera, to increase the contrast in the resultant electron backscatter diffraction pattern. The phosphor screen is located within the specimen chamber of the SEM at an angle of approximately 90degree to the pole piece and is coupled to a compact lens which focuses the image from the phosphor screen onto the CCD camera. In this configuration, some of the electrons which enter the sample backscatter and may escape. As these electrons leave the sample, they may exit at the Bragg condition related to the spacing of the periodic atomic lattice planes of the crystalline structure and diffract. These diffracted electrons can escape the material and some will collide and excite the phosphor causing it to fluoresce. Acquired with EMPA, SEM, TEM
Electron diffraction
Electron diffraction is a technique that allows determination of the crystal structure of materials. When the electron beam is projected onto a specimen, its crystal lattice acts as a diffraction grating, scattering the electrons in a predictable manner, and resulting in a diffraction pattern. Electron diffraction patterns are mainly contributed by elastic scattering. (X Zhou, G.E. Thompson, in Reference Module in Materials Science and Materials Engineering, 2017)
Electron energy loss spectrometry
a material is exposed to a beam of electrons with a known, narrow range of kinetic energies. Some of the electrons will undergo inelastic scattering, which means that they lose energy and have their paths slightly and randomly deflected. The amount of energy loss can be measured via an electron spectrometer and interpreted in terms of what caused the energy loss. With some care, and looking at a wide range of energy losses, one can determine the types of atoms, and the numbers of atoms of each type, being struck by the beam. The scattering angle (that is, the amount that the electron's path is deflected) can also be measured, giving information about the dispersion relation of whatever material excitation caused the inelastic scattering. Most common approach today is transmission EELS, in which the incident electrons pass entirely through the material sample. Usually this occurs in a transmission electron microscope (TEM), although some dedicated systems exist which enable extreme resolution in terms of energy and momentum transfer at the expense of spatial resolution. (https://en.wikipedia.org/wiki/Electron_energy_loss_spectroscopy, https://eels.info/about/techniques/eels-0)
Electron induced X-ray spectrometry
Technique to induce X-ray emission using an electron beam as the excitation, and measuring the energy spectra of emitted X-rays. Various X-ray emission peaks are associated with electron energy level quatum intervals for particular elements.
Electron microscopy imaging
ANAYTICAL ELECTRON MICROSCOPY
SCANNING ELECTRON MICROSCOPE
SCANNING ELECTRON MICROSCOPY
Technique that produces images by scanning an electron beam over a sample surface and measureing the intensity of electrons emitted from or transmitted through the sample.
Electron spectrometry
Analysis based on measuring the energy of electrons emitted from or that have interacted with a sample. Particular kinds of interactions and emission processes can be related to particular constituents in the sample.
Electron spin resonance age analysis
ELECTRON-SPIN RESONANCE AGE ANALYSIS
ELECTRON-SPIN RESONANCE AGE
a technique used to date materials by measuring the amount of unpaired electrons in crystalline structures that were previously exposed to natural radiation. The age of a substance can be determined by measuring the dosage of radiation since the time of its formation. (https://en.wikipedia.org/wiki/Electron_spin_resonance_dating). electron spin resonance (ESR) spectroscopy is a method for studying materials that have unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but the spins excited are those of the electrons instead of the atomic nuclei. (https://en.wikipedia.org/wiki/Electron_paramagnetic_resonance)
Electrothermal absorption spectrometry
ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY
A type of atomic absorption spectrometry where the sample is atomised using a probe which is rapidly heated by passing a current through it.
Elemental analysis
CARBON HYDROGEN NITROGEN ANALYSIS
CARBON HYDROGEN NITROGEN ANALYZER
CARBON HYDROGEN NITROGEN SULFUR ELEMENTAL ANALYSIS
CARBON HYDROGEN SULFUR ELEMENTAL ANALYSIS
CARBON NITROGEN SULFUR ANALYSIS
CARBON NITROGEN SULFUR ANALYZER
CARBON SULFUR ANALYSIS
CARBON SULFUR ANALYZER
CARBON SULPHUR ANALYZER
CHNS ANALYZER
CNS ANALYZER
ELEMENTAL ANALYSER
ELEMENTAL ANALYZER
THERMAL CONVERSION ELEMENTAL ANALYSIS
THERMAL CONVERSION ELEMENTAL ANALYZER
Technique to quantify carbon, hydrogen, nitrogen, sulfur and sometimes other elements by heating the sample at very high temperature (pyrolysis) in oxygen or oxygen free atmosphere, and assaying the resulting gaseous oxides. The products typically undergo some chemical refinement, with the final product analyzed by mass spectrometry or infrared/optical spectroscopy. Usually used for samples including organic material. (http://vocab.nerc.ac.uk/collection/L05/current/LAB01; https://en.wikipedia.org/wiki/Elemental_analysis).
map GEOROC 'MICROSCOPE VACUUM HEATING STAGE' to this technique based on data reported for technique: CO2, H2O, S.
Elemental analysis infrared spectrometry
Direct Mercury Analyzer
INFRARED QUANTIFICATION AND HIGH TEMPERATURE EVOLUTION ANALYSIS
INFRARED QUANTIFICATION AND HIGH TEMPERATURE EVOLUTION
Technique that uses an elemental analyzer (typically a pyrolysis process to extract volatile components in the sample) to extract the aliquots (typically as gas) to be analyzed using infrared spectrometry.
Elemental analysis isotope ratio mass spectrometry
Elemental analyzer - isotope ratio mass spectrometry
Measurement and study of the relative abundances of the different isotopes of an element in a material using a mass spectrometer which is coupled with an elemental analyzer. (Source: IUPAC; https://doi.org/10.1351/PAC-REC-06-04-06). Isotope and chemical analysis of H, C, N, O and S in a sample. (OSIRIS-REx confluence)
Elemental analysis mass spectrometry
Elemental analyzer mass spectrometry
elemental analyzer-mass spectrometry
Mass spectrometry method that uses an elemental analyzer (typically a pyrolysis process to extract volatile components in the sample) to extract the aliquots (typically as gas) to be atomized and passed to the mass analyzer.
Emission spectrometry
DIRECT READING OPTICAL EMISSIONS SPECTROSCOPY
is a method of chemical analysis that uses the intensity of light emitted from a flame, plasma, arc, or spark at a particular wavelength to determine the quantity of an element in a sample. The wavelength of the atomic spectral line in the emission spectrum gives the identity of the element while the intensity of the emitted light is proportional to the number of atoms of the element. The sample may be excited by various methods: flame, inductively coupled plasma, and spark being the most common. (https://en.wikipedia.org/wiki/Atomic_emission_spectroscopy)
Energy Dispersive electron induced X-ray spectrometry
Elemental spectra (ESPC) measurements
SCANNING ELECTRON MICROSCOPE-ENERGY DISPERSIVE XRAY ANALYSIS
SCANNING ELECTRON MICROSCOPE-ENERGY DISPERSIVE XRAYS
SCANNING TRANSMISSION ELECTRON MICROSCOPY ENERGY DISPERSIVE XRAY SPECTROMETER
SCANNING TRANSMISSION ELECTRON MICROSCOPY ENERGY DISPERSIVE XRAY SPECTROMETRY
TRANSMISSION ELECTRON MICROSCOPY- ENERGY-DISPERSIVE X-RAY SPECTROSCOPY
Analysis of X-ray spectra generated by electron beam excitation using a Transmission electron microscope instrument
Energy dispersive electron induced X-ray spectrometry
Energy dispersive X-ray fluorescence spectrometry
ENERGY-DISPERSIVE X-RAY FLUORESCENCE
energy-dispersive X-ray analysis (EDXA)
energy-dispersive X-ray fluorescence analysis (EDX)
energy-dispersive X-ray spectroscopy (EDS, EDXS)
an X-ray Fluorescence techniques used for elemental analysis applications. In EDXRF spectrometers, all of the elements in the sample are excited simultaneously, and an energy dispersive detector in combination with a multi-channel analyzer is used to simultaneously collect the fluorescence radiation emitted from the sample and then separate the different energies of the characteristic radiation from each of the different sample elements. Resolution of EDXRF systems is dependent upon the detector, and typically ranges from 150 eV -- 600 eV. The principal advantages of EDXRF systems are their simplicity, fast operation, lack of moving parts, and high source efficiency. (https://www.xos.com/EDXRF; Chai et al, 2021, https://doi.org/10.1515/pac-2019-0302)
Energy dispersive X-ray spectral data 2D raster
Energy-dispersive X-ray spectral data (EDS) - 2D raster
production of composition-related images by selecting particular X-ray wavelength intervals from a set of EDS spectra acquired in a raster on a sample surface. If one wavelenth interval is rpresented, get gray scale image. Can combine data from 3 intervals to generate more informative RGB images.
Energy dispersive X-ray spectrometry
ENERGY-DISPERSIVE X-RAY SPECTROSCOPY
Energy dispersive spectroscopy
A method for obtaining information about isolated portions of an X-ray spectrum, achieved electronically with devices that discriminate among various parts of a spectrum based on the energy rather than the wavelength of the radiation. The sample is exposed to a polychromatic (multiple wavelength) source (X-rays, or other energetic particles, e.g. electrons), and the resulting X-rays from the sample are analyzed by detectors with various electronic components required for energy discrimination. The X-ray spectrum is analyzed (in comparison to standards) to provide quantitative or qualitative analysis of constituents in the sample. (Skoog, Holler & Crouch, p. 289)
Energy-filtered transmission electron imaging
Energy-filtered transmission electron microscopy
The principle is to illuminate a very thin specimen with a beam of high energy electrons. Some of these electrons will interact with the specimen and result in elastic or inelastic scattering. Inelastic scattering results in both a loss of energy and a change in momentum, which in the case of inner shell ionization, the energy loss is characteristic of the element the electron interacted with. After the electron energy loss spectrum forms in the energy filter, an adjustable energy slit allows only electrons that have not lost energy to pass through to form the image. This is known as zero-loss filtering. The filtering prevents inelastically scattered electrons from contributing to the image plus enhances contrast image and resolution. In addition to zero-loss filtering, you can adjust the system to select electrons that have lost a specific amount of energy to obtain additional contrast effects and compositionally sensitive images. (https://eels.info/about/techniques/eftem)
Epithermal neutron activation analysis
method based on the measurement of the radioactivity or radiation produced in samples when they are irradiated with neutrons (Skoog, Holler & Crouch, p. 842). Epithermal neutrons have energies greater than thermal neutrons, but less than fast neutrons, 0.5 eV to 0.5 MeV. They can be described as incompletely moderated neutrons which are destined to become thermalised.
Extended X-ray absorption fine structure
X-ray absorption analysis in which the fine structure of the adsorption spectrum in the range 30 eV to 1 keV above the adsorption edge is used to measure the number and species of neighbouring atoms, their distance from the selected atom, and the thermal or structural disorder of their positions. In the EXAFS region, interference between the wave functions of the core and neighbouring atoms gives a periodic pattern that contains information characterizing the arrangement of atoms, including the number and type of neighbouring atoms and their distance to the absorbing atom. The method uses synchrotron radiation. (Chai et al, 2021, https://doi.org/10.1515/pac-2019-0302)
Fast neutron activation analysis
Method based on reactions with high-energy (14MeV) neutrons produced by a specialized small accelerator known as a neutron generator. FNAA is a rapid non-destructive technique used for the determination of lighter elements such as Nitrogen and Oxygen, and can routinely achieve precisions of 1-2% RSD of complex matrices. (https://elementalanalysis.com/naa/)
Fire assay emission spectrometry
NICKEL SULFIDE FIRE ASSAY ISOTOPE DILUTION ANALYSIS
NICKEL SULFIDE FIRE ASSAY ISOTOPE DILUTION
Used for Platinum group element (PGE) analyses. The sample is decomposed by heating with nickel sulfide to form a button that is then dissolved in acid. PGE constituents remain in the insoluble residue. After filtering, the residue is dissolved with aqua regia or a mixture of HCl and H2O2 and then determined by inductively coupled plasma-atomic emission spectrometry.
Fission track counting
FISSION TRACK ANALYSIS
FISSION TRACK
ISOTHERMAL PLATEAU FISSION TRACK ANALYSIS
ISOTHERMAL PLATEAU FISSION TRACK
Fission track age with correction applied for partial annealing using Isothermal plateau correction (https://doi.org/10.1016/1040-6182(92)90017-V)
Flame emission spectrometry
ATOMIC EMISSION SPECTROMETRY (FLAME PHOTOMETRY)
FLAME EMISSION SPECTROSCOPY
FLAME PHOTOMETRY
Emission spectrometry in which emission of photons is induced by introducing the sample into a flame.
Flow cytometry
Laboratory technique to determine the amount of DNA in cells tagged by fluorescent dye by measuring the intensity of fluorescence under a laser beam. (USGS; https://apps.usgs.gov/thesaurus/thesaurus-full.php?thcode=2&code=400). More generally, a technique for examining populations of cells or particles by suspending them in a fluid and passing them through a tube (ideally each particle individually discernible), and probing with a laser or other excitation source that will identify the particles of interest so they can be counted.
Fluorescence microscopy
Fluorescence microscopy is capable of imaging the distribution of a single molecular species based solely on the properties of fluorescence emission. Thus, using fluorescence microscopy, the precise location of intracellular components labeled with specific fluorophores can be monitored, as well as their associated diffusion coefficients, transport characteristics, and interactions with other biomolecules. In addition, the dramatic response in fluorescence to localized environmental variables enables the investigation of pH, viscosity, refractive index, ionic concentrations, membrane potential, and solvent polarity in living cells and tissues. Fluorescence is the property of some atoms and molecules to absorb light at a particular wavelength and to subsequently emit light of longer wavelength after a brief interval, termed the fluorescence lifetime. http://micro.magnet.fsu.edu/primer/techniques/fluorescence/fluorhome.html
Fluorescence spectrometry
ATOMIC FLUORESCENCE SPECTROMETRY
FLUOROMETRY
Fluorescence Spectroscopy
Fluorimetry
Spectrofluorometry
measurement the [energy, power?] of fluorescent radiation produced by a sample exposed to monochromatic radiation, used to identify the presence and the amount of specific molecules in a sample (https://en.wikipedia.org/wiki/Fluorometer). A type of electromagnetic spectroscopy that analyzes fluorescence from a sample. It involves using a beam of light, usually ultraviolet light, that excites the electrons in molecules of certain compounds and causes them to emit light; typically, but not necessarily, visible light (https://en.wikipedia.org/wiki/Fluorescence_spectroscopy)
Fluorescent in situ hybridization
Cytogenetic technique used to detect and localize the presence or absence of specific DNA sequences on chromosomes. It uses fluorescent probes that only bind to those parts of the chromosome with which they show a high degree of sequence complementarity. Note: FISH is often used for finding specific features in DNA for use in genetic counselling, medicine, and species identification. FISH can also be used to detect and localize specific RNA targets (mRNA, lncRNA and miRNA) in cells, circulating tumor cells, and tissue samples. In this context, it can help define the spatial-temporal patterns of gene expression within cells and tissues. (Source: IUPAC; https://doi.org/10.1515/iupac.90.0262, https://www.degruyter.com/database/IUPAC/entry/iupac.90.0262/html)
Focused ion beam scanning microscopy
Production of images by scanning an ion beam in a raster across a sample surface and detecting secondary or backscattered electrons from each point to generate an image. Instrument used is typically an electron microscope that has an additional ion beam excitation source.
Fourier transform infrared spectrometry
FOURIER TRANSFORM IR SPECTROSCOPY
A technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas. Light from a polychromatic infrared source is collimated and directed to a beam splitter. Half the light is directed to a fixed mirror and the rest to a moving mirror. The light from the two paths is recombined, resulting in constructive or destructive interference that is a function of wavelength in the polychromatic light source and the path retardation determined by different path lengths from the moving mirror. The recombined light is focused on the sample and reflected or transmitted light is refocused onto a detector. The difference in optical path length between the two arms to the interferometer is known as the retardation or optical path difference (OPD). An interferogram is obtained by varying the retardation and recording the signal from the detector for various values of the retardation. The interferogram when no sample is present is used as a reference to compare. When a sample is present the background interferogram is modulated by the presence of absorption bands in the sample. The interferogram is converted to a spectrum by Fourier transformation. (https://en.wikipedia.org/wiki/Fourier-transform_infrared_spectroscopy, Skoog, Holler & Crouch p. 188-192)
Fourier transform ion cyclotron resonance mass spectrometry
analysis of polar/apolar solvent-soluble organics can be performed using extremely high resolution mass spectrometry to identify molecular formulas (but not structures) with the elements C, H, O, N, S, Mg, Cl in a mixture.
Gamma counting
counting gamma rays emitted spontaneously from a sample; by looking at the the distribution of energy and frequency of the emitted gamma rays, the presence of elements emitting those gamma rays can be estimated.
Gamma ray spectrometry
GAMMA RAY SPECTROSCOPY
GAMMA SPECTROMETRY
Technique that measures the energy of gamma-rays emitted by a sample over a spectrum of wavelengths. By comparing the measured spectral distribution and energy to the known energy of gamma-rays produced by radioisotopes, the identity of the emitter can be determined.
Gas chromatography analysis
CARBON HYDROGEN NITROGEN GAS CHROMATOGRAPHY
ELECTRON CAPTURE GAS CHROMATOGRAPHY
GAS CHROMATOGRAPHY
A chromatography analysis in which the mobile phase is a gas. Subclasses are differentiated on the sample preparation workflow (e.g. pyrolysis) and the type of detector used to analyze the eluates. This vocabulary does not define an exhaustive set of subclasses.
Gas chromatography flame ionization detection
A gas chromatography method that uses a flame ionization detector (FID) to measure the concentration of organic species in a gas stream emerging from the column. An FID typically uses a Hydrogen/Air flame into which the sample is passed to oxidize organic molecules and produces electrically charged particles (ions). The ions are collected and produce an electrical signal which is then measured. (Source: IUPAC; https://doi.org/10.1515/pac-2017-0111)
Gas chromatography mass spectrometry
GAS CHROMATOGRAPHY-MASS SPECTROMETRY
Technique by which a mixture is separated into individual components by gas chromatography, followed by detection with a mass spectrometer. (Source: IUPAC; https://doi.org/10.1351/PAC-REC-06-04-06)
Gas chromatography thermal conductivity detection
Gas chromatography thermal conductivity detector
THERMAL CONDUCTIVITY DETECTOR ANALYSIS
THERMAL CONDUCTIVITY DETECTOR
A gas chromatography method that uses a Thermal Conductivity Detector to analyze inorganic gases (Argon, Nitrogen, Hydrogen, Carbon Dioxide, etc.) and small hydrocarbon molecules emerging from the chromatography column. The TCD compares the thermal conductivity of two gas flows - the pure carrier (reference) gas and the sample. Changes in the temperature of the electrically-heated wires in the detector are affected by the thermal conductivity of the gas which flows around this. The changes in this thermal conductivity are sensed as a change in electrical resistance and are measured. (NASA; UUID: f54fd6d0-9705-4f45-8c78-7eaba058b1b6)
Gas pycnometry
helium pycnometer
Measurement of the volume of a solid object, employing some method of gas displacement and the volume:pressure relationship known as Boyle's Law. The methods uses two chambers, one (with a removable gas-tight lid) to hold the sample and a second chamber of fixed, known (via calibration) internal volume -- referred to as the reference volume or added volume. The device has a valve to admit a gas under pressure to one of the chambers, a pressure measuring device -- usually a transducer -- connected to the first chamber, a valved pathway connecting the two chambers, and a valved vent from the second of the chambers. The volume of the sample is calculated from the known volumne of the empty sample chamber, the volume of the reference volume chamber, the pressure after gas is admitted to the sample chamber, and the pressure after expansion of the gas into both chambers. (https://en.wikipedia.org/wiki/Gas_pycnometer)
Geochronology techniques
Analytical techniques that have results interpreted to indicate the time interval since some event occurred in the history of a sample. Typically used to estimate crystallization ages, cooling ages (thermochronology), or exposure ages.
This section is very incomplete; techniques that occur in source repository data are included, but this is mostly a hook for a more complete vocabulary of geochronology methods, out of scope at this time 2023-03-14.
Geochronology techiques
40Ar-39Ar geochronology
40Ar/39Ar geochronology and thermochronology
determination of cooling age of a sample through one of several workflows. All the workflows involve irradiating the sample to produce Ar39 from K39, and then measuring the ratio of Ar40 to Ar39 in the irradiated sample. The Ar39 is a proxy for the potassium concentration, allowing determination of the temporal duration of K decay to accumulate radiogenic Ar since cooling of the sample below argon retention temperature.
Glow discharge mass spectrometry
Mass spectrometry using a source in which argon atoms in a low-density plasma impact the sample surface, sputtering atoms from the sample that are then ionized in the plasma and accelerated into the mass analyzer. Samples are analyzed in solid form. The sputtering and ionization approach is free from the matrix dependence response affecting most other elemental analysis techniques, minimizing the need for matrix matched standards.
Gradient ion chromatography analysis
GRADIENT ION-CHROMATOGRAPHY
Gradient ion chromatography
By varying the concentration of the eluant, ions with widely differing affinities for the separator resin can be eluted in one run (https://assets.thermofisher.com/TFS-Assets/CMD/Technical-Notes/tn-19-ic-gradient-elution-lpn032834-en.pdf). Components: 1) sample prep: load sample in solution; 2) elution - column, vary concentration of eluent; 3) detection- not specified
Gravimetric analysis
GRAVIMETRY
Gravimetry is the measurement of weight, a gravitational field, or density (Merriam-Webster, https://www.merriam-webster.com/dictionary/gravimetry. Accessed 6 Feb. 2023.) Gravimetric analysis measures the weight or concentration of a solid that has either formed from a precipitate or dissolved in a liquid. ( https://en.wikipedia.org/wiki/Wet_chemistry#Gravimetric_analysis; https://www.allthescience.org/what-is-bench-chemistry.htm).
Gutzeit test
ARSINE GUTZEIT REACTION
technique to detect arsenic, based on the reaction of arsenic gas with hydrogen ion to form yellow stain on mercuric chloride paper in presence of reducing agents like potassium iodide. It is also called as Gutzeit test and requires special apparatus. [not clear if this is quantitative or qualitative] (https://www.web-formulas.com/Formulas_of_Chemistry/Limit_Test_of_Arsenic.aspx; C.R. Sanger and O.F. Black, 1907, Proceedings of the American Academy of Arts and Sciences; Vol. 43, No. 8, pp. 297-324.)
High resolution inductively coupled plasma mass spectrometry (deprecated)
Mass spectrometry technique. Components 1) sample preparation: not specified; 2) ionization: Inductively-coupled plasma. 3) mass analyzer in which the the aperture width of the entrance slit situated between the ion optics and the mass analyzer, and an exit slit located between the mass analyzer and the detector assembly can be controlled. The narrower the slits are positioned, the higher the resolution (and lower the sensitivity); the wider the slits, the higher the sensitivity (and lower the resolution). (R. ArevaloJr., in Treatise on Geochemistry (Second Edition), 2014)
2024-02-22 SMR deprecate after team meeting discussion. Remove inScheme link to the conceptScheme. Any of the ICP MS techniques might be high resolution, and whether analyses were done in high-resolution modes is not always obvious in the data. Add high-resolution label in skos:altLabel.
Hybridization assay
DNA hybridization capture
Assay with specifically designed single-stranded DNA probe with a defined (known) nucleotide sequence usually immobilized on a surface (in such a case, the nucleic acid probe is called the capture probe). Note: The probe is used as a recognition element to test for the nucleotide sequence within the target DNA in the sample solution. If target DNA contains a sequence complementary to the probe, a hybrid dsDNA is formed. (Source: IUPAC; https://doi.org/10.1515/iupac.90.0262, https://www.degruyter.com/database/IUPAC/entry/iupac.90.0262/html). A type of Ligand Binding Assay (LBA) used to quantify nucleic acids in biological matrices. Hybridization assays can be in solution or on a solid support such as 96-well plates or labelled beads. Hybridization assays involve labelled nucleic acid probes to identify related DNA or RNA molecules (i.e. with significantly high degree of sequence similarity) within a complex mixture of unlabelled nucleic acid molecules. (https://en.wikipedia.org/wiki/Hybridization_assay)
Imaging techniques
Methods that produce 2-D or 3-D rasters that contain information about a sample, with data points that are spatially related to points on in the sample.
Induction heating analysis
INDUCTION HEATING
a technique for evaluation of the self-heating characteristics of particles? [based on interpretation of https://pubs.acs.org/doi/10.1021/acsomega.0c03332, not much online about this technique]. See also https://iris.unipv.it/bitstream/11571/1178389/6/After_revision.pdf . [would appear to be methods of analyzing the effectiveness of heating objects by electromagnetic induction] 'Induction heating (IH) is commonly used for heating and heat treatment. An accurate prediction of temperature distribution is required to optimize the heating parameters.... temperature-dependent B (magnetic flux density)-H (magnetic field strength) curves and changes in phase transformation under rapid heating were measured and used for IH analysis' ( https://doi.org/10.2355/isijinternational.ISIJINT-2018-552)
Inductively coupled plasma emission spectrometry
INDUCTIVELY COUPLED PLASMA (FURTHER DETAIL NOT PROVIDED)
INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROMETRY
INDUCTIVELY COUPLED PLASMA SPECTROMETRY
INDUCTIVELY-COUPLED PLASMA ATOMIC EMISSION SPECTROMETRY
TOTAL DIGESTION INDUCTIVELY COUPLED PLASMA EMISSION SPECTROMETRY
technique for determining the composition of a sample by heating it to the point that the material emits photons, and analyzing the wavelenth of the emitted photons. The sample is heated to emission temperatures using an inductively coupled plasma
Inductively coupled plasma mass spectrometry
FUSION-INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
HIGH-RESOLUTION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
HIGH-RESOLUTION INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY ISOTOPE DILUTION
ISOTOPE-DILUTION HIGH-RESOLUTION INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
ISOTOPE-DILUTION INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
QUADRUPOLE INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
SECTOR FIELD INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
Mass spectrometry technique in which the sample is introduced into an inductively coupled plasma to atomize and ionize the sample for inlet to mass analyzer. Components: 1) sample processing- dissolution, isotope dilution; 2) ionization: Inductively coupled plasma
Inductively coupled plasma optical emission spectrometry
INDUCTIVELY COUPLED PLASMA OPTICAL EMISSION SPECTROMETRY
INDUCTIVELY-COUPLED PLASMA OPTICAL EMISSION SPECTROSCOPY
technique for determining the composition of a sample by heating it to the point that the material emits light, and analyzing the wavelenth of the emitted ultraviolet to visible wavelength light. The sample is heated to emission temperatures using and inductively coupled plasma. The ICP-OES is an optical emission spectrophotometric technique that requires samples to be in solution form. The solution gets introduced to the hot plasma, which excites the electrons that emit energy at a given wavelength as they return to ground state. Each element emits energy at a specific wavelength according to its chemical character. The intensity of the energy emitted at a specific wavelength is proportional to the concentration of that particular sample. The elemental composition can be determined by comparing to a set of reference standards. The final elemental composition can be expressed as ppm or mg/L.
Infrared absorption spectrometry
INFRARED ABSORPTION SPECTROSCOPY
INFRARED GAS ANALYSIS
INFRARED GAS ANALYZER
Identify composition of gas(es) in a sample by detecting the absorption of infrared wavelengths that are characteristic of that gas. Infrared energy is emitted from a heated filament. By optically filtering the energy, the radiation spectrum is limited to the absorption band of the gas being measured. A detector measures the energy after the infrared energy has passed through the gas to be measured. This is compared to the energy at reference condition of no absorption. (https://en.wikipedia.org/wiki/Infrared_gas_analyzer)
Infrared optical spectrometry
Infrared photometry
measurement of the luminance, luminous intensity, or luminance of an infrared light source;
note that photometry is defined to weigh output results with the wavelength response of the human eye, but infrared light is not visible to the human eye, so this is apparently an incoherent concept.
Infrared reflectance
INFRARED REFLECTION MOISTURE ANALYSIS
measurement of the luminance, luminous intensity, or luminance of infrared light light reflected from a sample;
Infrared spectrometry
INFRA-RED SPECTROSCOPY
INFRARED SPECTROPHOTOMETRY
INFRARED SPECTROSCOPY
NEAR-INFRARED SPECTROMETRY
The infrared spectrometer (or spectrophotometer) measures the relative amount of energy as a function of the wavelength/frequency of the infrared radiation when it passes through a sample. The two types of the infrared spectrometer are dispersive infrared spectrometer (DS) and Fourier transform infrared spectrometer (FTIS). (https://conductscience.com/the-basics-of-infrared-spectrophotometry/)
Infrared transmission spectrometry
TRANSMISSION IR SPECTROSCOPY
In transmission IR spectroscopy, IR radiation is passed through a sample. Some of the IR radiation is absorbed by the sample and some of it is passed through (transmitted). The resulting spectrum represents the molecular absorption and transmission, creating a molecular fingerprint of the sample. (Q. Ye, P. Spencer, in Material-Tissue Interfacial Phenomena, 2017)
Instrumental neutron activation analysis
method based on the measurement of the radioactivity or radiation produced in samples when they are irradiated with neutrons (Skoog, Holler & Crouch, p. 842). Quantification of the elemental nuclei of interest is usually performed by gamma ray spectroscopy. Quantification of elements is accomplished by comparison with standards typically processed in the same manner. (https://www.nist.gov/laboratories/tools-instruments/instrumental-neutron-activation-analysis-inaa, https://serc.carleton.edu/research_education/geochemsheets/techniques/INAA.html). Instrumental indicates that no chemical pretreatment is performed on the sample prior to the irradiation process. The samples are simply packaged, irradiated for the specified length of time, allowed to decay, then counted, and the element results verified and reported. (https://elementalanalysis.com/naa/). Components: 1) sample irradiation 2) gamma ray spectrometry
Ion chromatography analysis
HIGH-PERFORMANCE ION CHROMATOGRAPHY
Ion chromatography
Ion exchange chromatography
LIQUID ION CHROMATOGRAPHY
PYROHYDROLYSIS COMBINED WITH ION CHROMATOGRAPHY
liquid chromatography analysis using conductivity detectors where a combination of weak ionic solvents are used to separate anions and cations of a solution, with the contribution of the solvent to conductivity suppressed just prior to detection; measures anions such as sulfate, nitrate, and chloride in hydrometers. Chromatography in which separation is based mainly on differences in the ion-exchange affinities of the sample components. (Source: IUPAC; https://doi.org/10.1515/pac-2017-0111)
Ion sensitive electrode analysis
ION SELECTIVE ELECTRODE
ION SENSITIVE ELECTRODE
SPECIFIC ION ELECTRODE ANALYSIS
SPECIFIC ION ELECTRODE
measurements of the potential of ion-selective electrodes is used to determine activity (not concentration) of ions. Such electrodes are relatively free from interference and provide a rapid and convenient means for quantitative estimations of numerous important anions and cations. The method is based on measuring the potential of electrochemical cells without drawing appreciable current. (Skoog, Holler, & Crouch, p. 601; https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Physical_Methods_in_Chemistry_and_Nano_Science_(Barron)/01%3A_Elemental_Analysis/1.07%3A_Ion_Selective_Electrode_Analysis)
Isotope ratio mass spectrometry
GAS CHROMATOGRAPHY AND CONTINUOUS FLOW ISOTOPE RATIO MONITORING MASS SPECTROMETRY
Isotope ratio mass spectrometry (IRMS) leverages magnetic sector mass spectrometry to enable high-precision measurement of the stable isotope content of a sample. Typical measurements target hydrogen, carbon, nitrogen, and oxygen analyses, although elements with masses up to and including sulfur can be measured. Solid, liquid, or gas phase samples are converted to simple gases then introduced to the IRMS. During analysis, an electron impact source ionizes sample-derived gas which is then accelerated down a flight tube, separated by mass, and quantified using a series of Faraday cups. (https://www.emsl.pnnl.gov/science/related-instrument/isotope-ratio-mass-spectrometry/1795)
Laser ablation inductively coupled plasma mass spectrometry
EXCIMER LASER ABLATION INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
FEMTO LASER MULTI-COLLECTOR INDUCTIVELY COUPLED PLASMA MAGNETIC SECTOR MASS SPECTROMETRY
INDUCTIVELY COUPLED PLASMA LASER ABLATION (FURTHER DETAIL NOT PROVIDED)
LASER ABLATION DOUBLE-FOCUSING MAGNETIC SECTOR FIELD INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
LASER ABLATION INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
LASER ABLATION MICROPROBE INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
LASER ABLATION MICROPROBE INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
LASER ABLATION MICROPROBE MULTI-COLLECTOR INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
LASER ABLATION MULTI-COLLECTOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
LASER ABLATION MULTICOLLECTOR ICPMS
LASER ABLATION PLASMA IONISATION MULTI-COLLECTOR MASS SPECTROMETRY
LASER ABLATION QUADRUPOLE INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
LASER ABLATION-INDUCTIVELY COUPLED PLASMA-TIME OF FLIGHT-MASS SPECROMETRY
LASER PROBE MICROANALYSIS INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
Mass spectrometry technique in which a laser beam is focused on a spot on the sample surface to atomize sample material from that spot, for subsequent introduction in to inductively coupled plasma to ionize for inlet into mass analyzer. Components 1) sample prepartion: polished surface 2) ionization: laser, inductively coupled plasma. Point analysis.
Laser ablation mass spectrometry
LASER-MICROPROBE ANALYSIS
SINGLE CRYSTAL LASER FUSION ANALYSIS
SINGLE CRYSTAL LASER FUSION TECHNIQUE
Mass spectrometry technique in which a laser beam is focused on a spot on the sample surface to atomize sample material from that spot, for subsequent ionization and intlet to mass analyzer. Compononets 1) sample prepartion: polished surface 2) ionization: laser. Point analysis.
Laser ablation resonance ionization mass spectrometry
laser ablation resonance ionisation mass spectrometer
A portion of a solid sample is vaporized by a laser; ablated atoms and molecules, are both neutral and charged. Charged particles are usually swept away by an electric field, and one or more pulsed lasers tuned to specific resonances in the element of interest are passed through the remaining neutral cloud to affect efficient ionization of that element, while other elements and molecules are largely unaffected. The photoions are then extracted into the mass analyzer, commonly a time-of-flight analyzer.
Laser absorption spectrometry
LIQUID-WATER ISOTOPE ANALYSIS
LIQUID-WATER ISOTOPE ANALYZER
Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS)
quantitative measurements of gas temperature and composition based on the amount of light that is absorbed at a given excitation wavelength, proportional to the fraction of molecules in the absorbing quantum state. Molecules can absorb photons at certain wavelengths which causes them to transition from a lower energy level to an upper energy level.
Related resource: Liquid-Water Isotope Analyzer uses tunable, off-axis integrated-cavity High-Resolution Laser Absorption Spectroscopy to measure hydrogen and oxygen isotopic composition (delta 18O and delta 2H) in liquid water samples. (https://eal.ucmerced.edu/instrumentation/water-isotope-analyzer; https://inis.iaea.org/search/search.aspx?orig_q=RN:43008377)
Laser fluorination mass spectrometry
IR-laser fluorination mass spectrometry
LASER FLUORINATION
Laser Assisted Fluorination for Bulk Oxygen Isotope Ratio Measurements
Laser fluorination analysis
in situ ultraviolet laser fluorination
infrared laser fluorination
Technique wherein oxygen is quantitatively extracted from oxygen-bearing compounds, without isotopic fractionation, and simultaneously converted to diatomic oxygen (O2) gas, and then analyzed with isotope-ratio mass spectrometer (IRMS) to determine its delta 17O and delta 18O ratios. (https://sil.uoregon.edu/laser-fluorination/)
Laser Induced Breakdown Spectrometry
Laser Induced Breakdown Spectroscopy
rapid chemical analysis technique that uses a short laser pulse to create a micro-plasma on the sample surface. The highly energetic laser pulse is focused on sample surface to form a plasma, which atomizes and excites atoms from the sample, which then emit light that is spectroscopically analyzed. Advantages include: 1) minimal sample preparation; 2) fast measurement time (second) for a single spot analysis; 3) Broad elemental coverage, including lighter elements, such as H, Be, Li, C, N, O, Na, and Mg; 4) ability to raster the sample surface and make depth profiles; 5) Thin-sample analysis with no substrate interference. A typical detection limit of LIBS for heavy metallic elements is in the low-PPM range. LIBS is applicable to a wide range of sample matrices that include metals, semiconductors, glasses, biological tissues, insulators, plastics, soils, plants, soils, thin-paint coating, and electronic materials.
Laser ionization mass spectrometry
ISOTOPE-DILUTION RESONANCE-IONIZATION MASS SPECTROMETRY
LASER PLASMA IONIZATION MASS SPECTROMETRY
RESONANCE-IONIZATION MASS SPECTROMETRY
resonance ionisation mass spectrometer
Technique that uses laser to induce plasma ionization. The laser plasma is sustained between a pneumatic nebulizer and the inlet capillary of the mass analyzer. To maintain stable conditions in the droplet-rich spray environment, the plasma was directly fed by the fundamental output (lambda = 1064 nm) of a laser. Ionization by the laser-driven plasma resulted in signals of intact analyte ions of several chemical categories. Use for mass-spectrometric determinations of polar and nonpolar analytes in solution. (https://doi.org/10.1021/acs.analchem.9b00329)
Laser ablation split stream mass spectrometry
LASER ABLATION SPLIT STREAM MASS SPECTROMETRY
LASER ABLATION-SPLIT STREAM ANALYSIS
LASER ABLATION-SPLIT STREAM
The output from laser ablation of a single analysis spot is split between two mass spectrometers (typically ICPMS). The technique allows simultaneous analyses of different geochemical systems in mineral samples using two or more mass spectrometers. An important application is the determination of the complementary isotopic systems of Lu-Hf and U-Pb (age)(https://assets.thermofisher.com/TFS-Assets/CMD/Application-Notes/AN-30298-ICP-MS-Laser-Ablation-Split-Stream-AN30298-EN.pdf)
LECO furnace analysis
LECO FURNACE
LECO analysis uses infrared absorption and thermal conductivity to measure combustion gases from sample. This process determines the presence and concentration of carbon, sulfur, oxygen, nitrogen or hydrogen. LECO analysis converts the elements from a sample into their oxidized form by utilizing either the gas fusion method (Hydrogen, Nitrogen, and Oxygen) or the combustion method (Carbon and Sulfur). (https://www.element.com/materials-testing-services/chemical-analysis-labs/leco-analysis)
Liquid chromatography analysis
HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
A chromatography analysis in which the mobile phase is a liquid
Liquid chromatography mass spectrometry
technique used to separate, detect, identify, and quantify components of a complex mixture. The solid sample is extracted in a solvent to pull out soluble target compounds; this creates both a solid residue and a liquid extract. The extract can be subjected to additional procedures, for cleanup or exposure to acid vapor to break apart large molecules. The final extracted solution is injected into the LC, which separates compounds in the solution and then passes them into the MS, where their mass spectra are measured. Each time point on the chromatogram is linked to a mass spectrum from which the most intense signals are fragmented at defined CID (colision induced dissociation) energy. The combination of retention time (i.e., how long it takes for the compound to pass through the LC) and mass spectrum allows for identification of the compounds when compared to standards. The LC-MS-MS converted data is in a unversal format of data called mzML and used internationally in LC-MS-MS analytical community of small molecules, peptides to proteins. mzML is a universal Mass spectrometry format. xml namespace =http://psi.hupo.org/ms/mzml; schema location http://psidev.info/files/ms/mzML/xsd/mzML1.1.0.xsd
Liquid chromatography organic carbon detection
Liquid chromatography -- organic carbon detection (LC-OCD) is an analytical technique for identification and quantification of natural organic matter (NOM) constituents in aquatic environments and water-soluble synthetic organic matter in water.
Liquid inlet inductively coupled plasma mass spectrometry
SOLUTION-NEBULIZED INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
STANDARD ADDITION SOLUTION INDUCTIVELY-COUPLED PLASMA MASS-SPECTROMETRY
TOTAL DIGESTION-INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
ULTRASONIC NEBULIZATION INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
Mass spectrometry technique in which sample is dissolved in a liquid reagent and nulized or vaporized by one of several techniques to introduce into an inductively coupled plasma to atomize and ionize for intlet to mass analyzer. Components: 1) sample preparation: dissolution, nebulize to introduce into plasma (this is normal method to get sample into ICP...) 2) ionization: inductively coupled plasma
Lock in thermography
The principle of lock-in thermography is based on the application of a periodic input energy wave (i.e. thermal emitter, ultrasound, microwave, eddy current, flash or xenon lamp, halogen lamp, or laser) to the surface of the object being examined and analyzing the resulting local temperatures on the surface of the object using an infrared camera. When the input energy wave penetrates the object's surface, is it absorbed and phase shifted. When the input wave reaches areas within the object where the thermophysical properties are not homogeneous in relation to the surrounding material, (i.e. at delaminations or inclusions), the input wave is partially reflected. The reflected portion of the wave interferes with the incoming input wave at the surface of the object, causing an interference pattern in the local surface temperature, which oscillates at the same frequency as the thermal wave. The internal structure of the object being examined can then be derived by evaluating the phase shift of the local surface temperatures in relation to the input energy wave. The ability to derive internal thermophysical inconsistencies within the object, however, requires that the input energy source be used at an optimal frequency, which depends on both the thermophysical characteristics of the object as well as its thickness. (https://movitherm.com/knowledgebase/what-is-lock-in-thermography/)
Loss on ignition analysis
IGNITION ANALYSIS
IGNITION
Method consists of igniting (vigorous heating) a sample at a designated temperature which enables volatile substances within the sample material to escape, until the mass of the sample ceases to change. This process is often performed within air but may be done in another inert or reactive atmosphere. Loss on Ignition measures the organic matter content in samples. The volatile materials lost during the analysis typically consist of combined water (hydrates, for example) and CO2 from carbonates. (https://www.precisa.com/blog/what-is-loss-on-ignition-loi)
GEOROC reports analytes for 'STEPPED HEATING ANALYSIS' as CO2 and H20, so interpret as a loss on ignition technique.
Magnetic field measurement
Techniques for measuring magnetic field. [TBD--what are the actual techniques...]
Manometry
EXTRACTION HYDROGEN MANOMETRY
measurement of the pressure of gases or vapors
Mass spectrometry
ISOTOPE-DILUTION MASS SPECTROMETRY
ISOTOPE-RATIO MASS SPECTROMETRY
MASS SPECTROMETRY ISOTOPE DILUTION
Study of matter through the formation of gas-phase ions that are characterized using mass spectrometers by their mass, charge, structure, and/or physico-chemical properties. (Source: IUPAC; https://doi.org/10.1351/PAC-REC-06-04-06). Atomic mass spectrometric analysis involves: (1) atomization, (2) conversion of a substantial fraction of the atoms formed in step 1 to a stream of ions (usually singly charged positive ions), (3) separating the ions formed in step 2 on the basis of their mass-to-charge ratio (m/z), where m is the mass number of the ion and z is the number of fundamental charges that it bears, and (4) counting the number of ions of each type or measuring the ion current produced when the ions formed from the sample strike a suitable transducer. (Skoog, Holler & Crouch, p. 253). Molecular mass spectrometry is used to determine the structures of inorganic, organic, and biological molecules and the qualitative and quantitative composition of complex mixtures; The appearance of mass spectra for a given molecular species strongly depends on the method used for ion formation. That these methods fall into three major categories: gas-phase sources, desorption sources, and ambient desorption sources. (Skoog, Holler & Crouch, p. 502)
Analytical methods for geochemistry and cosmochemistry
This concept scheme contains skos concepts for analysis methods used to produce observation results with information about the physical properties, chemical or isotopic composition, crystallography, or molecular structure of material samples. Based on spreadsheet compilation of method vocabularies from Geo.X, GEOROC, PetDB and OSIRIS-REx. Definitions added and updated based on web research, and SKOS serialization by S.M. Richard. Note that although there are high-level method categories for 'Physical property measurements' and the 'Bioanalytical method', these are placeholders and only include a few examples that are relevant to analytical methods in geo- or cosmochemistry.
2023-02-14 S.M. Richard. Draft generated, based on spreadsheet compilation of method vocabularies from Geo.X, GEOROC, PetDB and OSIRIS-REx (Astromat). Definitions added and updated and SKOS serialization by S.M. Richard.
2023-05-01 SMR. Add provenance and better source information, prepare for posting to Australian Research Data Commons (ARDC) Research Vocabularies Australia.
2023-05-26 SMR add funding acknowledgement for Astromat support from NASA planetary sciences division, using schema.org/funding property.
2023-06-17 SMR put the dcterm agent objects in https://w3id.org/geochem/1.0/agent URI space (instead of analyticalmethod). Add 'and cosmochemistry' in vocab title.
2024-02-22 SMR some classes have multiple skos:notation values, pick one to keep as a unique notation, move others to altLabel. Add some other altLabels for MC and ID TIMS, SIMS. Deprecate Add SHRIMP (Sensitive high mass resolution ion microprobe) as a method under Secondary ionization mass spectrometry because of its frequent use as a method in the literature. Fix Duplicate notation value-- GC to GAMMA, GAMMA to GR-S. Deprecate 'High resolution inductively coupled plasma mass spectrometry'. TBD--add notations for classes that don't have notation, standardize hyphenation of skos:notation values.
Analytical methods for geochemistry
Compilation of this vocabulary supported by funding from the US National Aeronautics and Space Administration (NASA) Planetary Sciences Division for the Astromaterials Data System at Lamont Doherty Earth Observatory, Columbia University
Australian Research Data Commons, Research Vocabularies Australia
Micromass multiprep mass spectrometry
MICROMASS MULTIPREP MASS SPECTROMETER
Multiprep automated sample preparation device is used to digest powdered biogenic or mineral carbonate material with phosphoric acid or to equilibrate water samples with carbon dioxide or hydrogen.(Micromass is the instrument manufacturer). Output from multiprep goes to mass spectrometer. Example systems e.g. https://www.atmos.albany.edu/geology/webpages/sirmslab.html are doing stable isotope analyses. Components: 1) sample preparation: multiprep device
Microprobe two step laser mass spectrometry
microprobe two-step laser mass spectrometer
Microprobe two-step laser mass spectrometry (microL2MS) is a technique that allows the detection and characterization of organic molecules. Output for point analyses consist of time-of-flight spectra and where appropriate low resolution optical location images. Each spectrum represent the time varying signal recorded by the microchannel plate (MCP) detector assembly in microL2MS instrument following laser photoionization of neutral species liberated from the surface a sample by a preceeding laser desorption pulse. microL2MS instrument output data products will consist of a variable number of spectra and image files depending on the nature of the sample and number of analysis locations.
Microscopic X-ray imaging
X-RAY MICROSCOPY ANALYSIS
Technique uses electromagnetic radiation in the X-ray band to produce magnified images of objects. Since X-rays penetrate most objects, there is no need to specially prepare them for X-ray microscopy observations. Because X-rays do not reflect or refract easily and are invisible to the human eye an X-ray microscope exposes film or uses a charge-coupled device (CCD) detector to detect X-rays that pass through the specimen. It is a contrast imaging technology using the difference in absorption of soft X-rays in the water window region (wavelengths: 2.34-4.4 nm, energies: 280-530 eV) by the carbon atom (main element composing the living cell) and the oxygen atom (an element of water). (https://en.wikipedia.org/wiki/X-ray_microscope)
Microscopy
Observation of samples using visible light optical systems
Micro X-ray fluorescence spectrometry
Micro X-ray fluorescence spectroscopy
Micro X-ray fluorescence
Measurement method of X-ray fluorescence used to measure amounts of elements in a material. Micro-XRF analysis uses highly brilliant X-ray sources (synchrotron source and spot size 100 nm to 2 micron) and microfocussing X-ray optics to give femtogram to attogram detection limits. (Source: IUPAC; Chai et al, 2021, https://doi.org/10.1515/pac-2019-0302).
Mini cryogen free measurement system for thermal conductivity
measure the bulk thermal conductivity of a bar-shaped sample specimen across a wide range of temperatures, producing a table with thermal conductivity vs temperature. (OSIRIS-REx confluence). The label implies that the technique measures thermal conductivity at low temperatures, using a device that does not require liquid nitrogen or liquid helium for cooling. [need more information]
Moisture analysis
DUPONT SOLID'S MOISTURE ANALYSIS
[might be: ]The Model 510 Moisture Analyzer (E. I. du Pont de Nemours & Co.) the sensing element is a quartz crystal coated with a hygroscopic material. The resonant frequency of such a crystal depends on the crystal mass (King, 1964). The mass (and, hence, resonant frequency) changes with the adsorption of moisture. A typical sensitivity factor is about 1 Hz per A thickness of added material. Two crystals are alternately exposed to sample air and dry air. The frequency difference between the two is indicated on the analyzer scale in parts per million (ppm) water vapor by volume. (https://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_138.pdf)
Mossbauer spectrometry
Mossbauer spectroscopy
In its most common form a solid sample is exposed to a beam of gamma radiation, and a detector measures the intensity of the beam transmitted through the sample. The atoms in the source emitting the gamma rays must be of the same isotope as the atoms in the sample absorbing them. The source is accelerated through a range of velocities using a linear motor to produce a Doppler effect and scan the gamma ray energy through a given range. In the resulting spectra, gamma ray intensity is plotted as a function of the source velocity. At velocities corresponding to the resonant energy levels of the sample, a fraction of the gamma rays are absorbed, resulting in a drop in the measured intensity and a corresponding dip in the spectrum. The number, positions, and intensities of the dips (also called peaks; dips in transmitted intensity are peaks in absorbance) provide information about the chemical environment of the absorbing nuclei and can be used to characterize the sample. (https://en.wikipedia.org/wiki/M%C3%B6ssbauer_spectroscopy)
Multi collector inductively coupled plasma mass spectrometry
HIGH-RESOLUTION MULTI-COLLECTOR INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY
ISOTOPE-DILUTION MULTI-COLLECTOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
MULTI-COLLECTOR INDUCTIVELY COUPLED PLASMA MAGNETIC SECTOR MASS SPECTROMETRY
MULTICOLLECTOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY
MULTICOLLECTOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY-ISOTOPE DILUTION
Quadrupole and Multi-Collector (MC) Inductively coupled plasma mass spectrometry (ICP-MS) are grouped into one 'analtyical technique' by O-REx sample analysis team.
Nanoindentation and microindentation
determine mechanical properties of materials from the load versus displacement curves as a micro indentor is pressed into the sample surface
Instruments that implement this method (atomic force microscopes) can also generate topographic images of indents, a separate method here under 'AFM topography imaging'
Nanoscale infrared spectrometry
Technique uses a pulsed, tunable IR source to excite molecular absorption in a sample. As the sample absorbs radiation, it heats up, leading to rapid thermal expansion that excites resonant oscillations of the cantilever of an atomic force microscope (AFM), which is detected using the standard AFM photodiode measurement system. These induced oscillations decay in a characteristic ringdown that can be analyzed to extract the amplitudes and frequencies of the oscillations. By measuring the amplitudes of the cantilever oscillation as a function of the source wavelength, local absorption spectra are created. (https://doi.org/10.1016/S1369-7021(10)70205-4)
Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center, NASA
Global Change Master Directory (GCMD), GCMD Keywords, Version 18.0
Terms that are defined or have related instruments identified in the GCMD vocabulary. The mapping is not complete.
Negative ion thermal ionization mass spectrometry
ISOTOPE-DILUTION NEGATIVE ION THERMAL-IONIZATION MASS SPECTROMETRY
NEGATIVE ION THERMAL-IONIZATION MASS SPECTROMETRY
NEGATIVE THERMAL IONIZATION MASS SPECTROMETRY ISOTOPE DILUTION
NEGATIVE THERMAL IONIZATION MASS SPECTROMETRY
NEGATIVE THERMAL-IONIZATION MASS SPECTROMETRY ISOTOPE DILUTION
NEGATIVE THERMAL-IONIZATION MASS SPECTROMETRY
Mass spectrometer techinque. Components: 1) sample processing- dissolution, isotope dilution; 2) ionization: thermal ionization; analyte: negative ions.
Neutron activation analysis
method based on the measurement of the radioactivity or radiation produced in samples when they are irradiated with neutrons (Skoog, Holler & Crouch, p. 842). Quantification of the elemental nuclei of interest is usually performed by gamma ray spectroscopy (high resolution germanium detector), or by beta counting (low background proportional or liquid scintillation counting) when pure beta emitters are measured. Quantification of elements is accomplished by comparison with standards typically processed in the same manner. (https://www.nist.gov/laboratories/tools-instruments/instrumental-neutron-activation-analysis-inaa, https://serc.carleton.edu/research_education/geochemsheets/techniques/INAA.html). Components: 1) sample irradiation 2) gamma ray spectrometry
Neutron counting
DELAYED NEUTRON COUNTING
NEUTRON COINCIDENCE COUNTING
Neutrons from spontaneous fission or induced fission in a sample are emitted essentially simultaneously. In many cases it is possible to obtain a nearly unique signature for a particular nuclear material. The measurement can be made in the presence of neutrons from room background or (a,n) reactions because these neutrons are noncoincident, or random, in their arrival times. used to measure the quantity of uranium or plutonium present in a sample. (https://www.lanl.gov/org/ddste/aldgs/sst-training/_assets/docs/PANDA/Principles%20of%20Neutron%20Coincidence%20Counting%20Ch.%2016%20p.%20457-492.pdf). A delayed neutron is a neutron emitted after a nuclear fission event, by one of the fission products (or actually, a fission product daughter after beta decay), any time from a few milliseconds to a few minutes after the fission event. (https://en.wikipedia.org/wiki/Delayed_neutron).
Neutron irradiation noble gas mass spectrometry
NOBLE-GAS METHOD
neutron-irradiation noble gas mass spectrometry
Techique that exposes sample to neutron-irradiation to produce noble gas isotopes from halogen isotopes within the sample. NI-NGMS requires only small sample masses (~1 mg). The method provides information on the abundances and ratios of the halogen (Cl, Br and I) and the noble gas (Ar, Kr and Xe) elements. (OSIRIS-REx confluence). Technique to measure the abundances of Cl, K, Br, I, Ca, Ba and U, in which samples are exposed to a high neutron fluence to produce nucleogenic noble gas isotopes in abundances proportional to those of the parent elements. (https://goldschmidtabstracts.info/2014/2145.pdf). The noble gas isotopes are liberated from the sample by heating and analyzed with a mass spectrometer (https://www.sciencedirect.com/science/article/pii/S0009254116302339)
Next generation sequencing
Massive parallel sequencing
Massively parallel sequencing
Second generation sequencing
Determination of nucleotide sequence (the DNA primary structure) using non-Sanger-based high-throughput DNA sequencing technologies where millions of DNA strands can be sequenced in parallel. (Source: IUPAC; https://doi.org/10.1515/iupac.90.0262, https://www.degruyter.com/database/IUPAC/entry/iupac.90.0262/html)
Noble gas mass spectrometry
Noble gas and nitrogen static mass spectrometry
Rare-gas mass spectrometry
Noble gases (He, Ne, Ar, Kr, Xe ) are extracted from samples by heating in a vacuum with an IR laser or in a heated crucible. The extracted gases are purified using hot metals or alloys (and cold traps). Noble gas elements can be separated using cryogenic traps and sequentially analyzed by separation of the ions according to their mass/charge ratio and a collection block consisting of single or multiple Faraday cups and/or electron multipliers. (OSIRIS-REx confluence; https://nvlpubs.nist.gov/nistpubs/jres/38/jresv38n6p617_A1b.pdf)
TBD: check if Noble Gas and Nitrogen Static mass spectrometry is something different
Nuclear magnetic resonance spectrometry
Nuclear magnetic resonance spectroscopy
Nuclear magnetic resonance
Measurement principle of spectroscopy to measure the precession of magnetic moments placed in a magnetic induction based on absorption of electromagnetic radiation of a specific frequency by an atomic nucleus. Nuclei having a suitable magnetic moment include 1H, 13C, 15N, 19F, 31P. The technique is used as a method of determining structure of organic molecules, or as a mechanism for quantification. (Source: IUPAC; https://iupac.org/wp-content/uploads/2019/10/PAC-REC-19-02-03.R2_PR191002MC.pdf). A spectroscopic technique that observes the signal produced by nuclear magnetic resonance of the atomic nuclei in a sample when exposed to excitation by radio waves. The signal is related to local magnetic fields around atomic nuclei. The intramolecular magnetic field around an atom in a molecule changes the resonance frequency, thus giving access to details of the electronic structure of a molecule and its individual functional groups. The electromagnetic waves emitted by the nuclei of the sample as a result of perturbation by a weak oscillating magnetic field are detected with sensitive radio receivers. Upon excitation of the sample with a radio frequency (60--1000 MHz) pulse, a nuclear magnetic resonance response - a free induction decay (FID) - is obtained. It is a very weak signal, and requires sensitive radio receivers to pick up. A Fourier transform is carried out to extract the frequency-domain spectrum from the raw time-domain FID. As the fields are unique or highly characteristic to individual compounds NMR spectroscopy is the definitive method to identify monomolecular organic compounds. https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance_spectroscopy
Nuclear microprobe analysis
NUCLEAR MICROPROBE
PROTON MICROPROBE ANALYSIS
PROTON MICROPROBE
Scanning Proton Microprobe
scanning proton microscopy (SPM)
Technique in which a focused beam of Me V light-mass ions is scanned across a sample surface. The most commonly used Me V ion is the proton, which is why the Nuclear Microprobe is also sometimes called the Scanning Proton Microprobe. However, other MeV light ions can generate the same analytical signals as protons, and are preferred for some of the analytical techniques described. The focused beam is scanned over the sample surface, and the strength of the relevant analytical signal is measured at each position in the scanned area to generate an image of the sample. There are many different types of interaction that can occur when an MeV ion is incident on a sample, and each one forms the basis of an analytical technique: Particle-Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS), Nuclear Reaction Analysis (NRA) -- nuclear reaction products such as alpha particles, protons, neutrons, or gamma rays are emitted. The energy of these charged reaction products is measured using a surface barrier detector . (https://www.annualreviews.org/doi/pdf/10.1146/annurev.ns.42.120192.000245)
Nuclear particle track counting
[? guess ] Technique used to measure the 222Rn concentration (Bq.m-3) in occupational and domestic environments. The detector employed is the LEXAN plastic. An electrochemical process is used to reveal the tracks generated at the detector surface by the incidence of the alpha particles from radon and its progeny decay ( Andrade Pinheiro and Cardozo, 2009, https://inis.iaea.org/collection/NCLCollectionStore/_Public/41/057/41057319.pdf)
Nuclear reaction spectrometry
NUCLEAR REACTION ANALYSIS
ion-beam-based analytical method with direct observation of nuclear reactions induced by highly energetic (Me V domain) charged particles. All these reactions are characterized by the prompt emission of charged particles (protons or helium-4 ions) and/or gamma-rays. Method is dedicated to quantitative determination of volumetric distributions of light elements from Z = 1 (H) to Z = 41 (Ga) in the near surface region of solids. (https://doi.org/10.1002/9780470027318.a6208.pub2, https://en.wikipedia.org/wiki/Nuclear_reaction_analysis)
Optical emission spectrometry
DROES
OPTICAL EMISSION SPECTROSCOPY
chemical analysis technique in which sample is heated to temperatures at which atoms emit light at characteristic wavelengths; the light is analyzed spectroscopically and compared with standards to determine composition
Optical spectrometry
OPTICAL SPECTROSCOPY
SPECTROPHOTOMETRY
analytical techniques in which the spectra of visible or ultraviolet light emitted or absobed by, or transmitted through a sample is analyzed to obtain information about the composition of the sample.
Orbitrap mass spectrometry
Orbitrap is an ion trap mass analyzer consisting of an outer barrel-like electrode and a coaxial inner spindle-like electrode that traps ions in an orbital motion around the spindle. The image current from the trapped ions is detected and converted to a mass spectrum using the Fourier transform of the frequency signal. (https://en.wikipedia.org/wiki/Orbitrap)
Techniques that don't fit in other categories.
Particle beam excitation
ION MICROPROBE ANALYSIS
ION MICROPROBE
Analytical techniques that involve exposing the sample to a beam of accelerated particles (ions or electrons), and detecting and measureing radiation or emitted particles resulting from interaction of the beam with the sample.
Particle cohesion determination
Measurement of cohesive force between dust-sized particles that are close or in direct contact is measured with an Atomic Force Microprobe. One particle is affixed to the pin on the cantilever arm of an AFM, while the second particle is fixed to a substrate. Particles should be characterized in SEM to determine particle shape and local radii at size of contact.
Particle counting
RADON METHOD can we clarify more???
RADON METHOD
RN-EMANATION ANALYSIS
RN-EMANATION
Technique that detects and counts photons or particles (neutrons, alpha particles) that are spontaneously emitted from a sample due to radioactive decay of elements in the sample.
Data in GEOROC for this technique are Ra226 (Radium!) activity. Radium-226 (1600 year half life) yields an alpha particle and Radon-222; Radon-222 (3.82 day half life) yields an alpha particle and Polonium-218... (https://www.nist.gov/image-23773). Guess Radon is being measured as proxy for Radium, and the Radon concentration measured using alpha particle or gamma ray counting....
Radon method is lumped in this group. https://nrpp.info/standards/measurement-methods/ lists 16 methods for anlyzing radon concentration. All are based on counting radioactive decay products from radon in air, water, or collected on charcoal. Some use gamma counting, some count tracks from alpha particles. lacking more detail, assign to 'Particle counting'
Activation analysis
PARTICULE INDUCED GAMMA-RAY EMISSION ANALYSIS
PARTICULE INDUCED GAMMA-RAY EMISSION
Particle induced activation analysis
Measurement of elemental or isotopic contents in a specified amount of a material by irradiation with appropriately chosen penetrating radiation, either elementary particles or electromagnetic radiation, to induce nuclear reactions in the nuclei of the analyte, producing radioactive atoms. Analysis of the radiation emitted by these atoms when they decay allows determiniation of the composition of the sample. (Chai et al, IUPAC recommendations, 2021, https://doi.org/10.1515/pac-2019-0302)
Particle induced X-ray spectrometry
Proton Induced X-ray Emission
An X-ray spectrometry technique in which emisssion of X-rays is induces by bombarding a spot on the sample with ions or sub-atomic particles other than electrons, e.g. neutrons, protons, muons (Chai et al, 2021, https://doi.org/10.1515/pac-2019-0302).
Particle size distribution analysis
Estimation of a particle size distribution by measuring diameter of a set of grains spread on a sample platter.
Particle spectrometry
Analysis of the energy distribution of particles emitted from a sample.
Penfield method analysis
PENFIELD METHOD
Penfield, S. L., 1894, On some methods for the determination of water: American Journal of Science, v. 48, no. 283, p. 30-37. Determination of water by 'heating a weighed quantity of mineral in a closed glass tube, weighing the tube plus the water, then drying and weighing again'. Modified method (Shapirro, 1975, p. 55-56, https://pubs.usgs.gov/bul/1401/report.pdf) water is driven from the sample when it is heated in a Pyrex test tube with sodium tungstate as a flux (Shapiro and Brannock, 1955b). The water is condensed on a piece of preweighed filter paper in the upper part of a test tube that is cooled by crushed ice in a polyethylene jacket surrounding the test tube during the analysis.
pH measurement
Measurement of hydrogen ion concentration in a liquid. Various techniques are used.
Photometry
measurement of the luminance, luminous intensity, or luminance of a light source; with an output weighted by the wavelength response of the human eye. (Source: NASA; UUID; 806d0bc3-8d08-4418-800b-972292f3db99)
Photon activation analysis
INSTRUMENTAL PHOTON ACTIVATION ANALYSIS
Activation of a sample with high-energy photons (gamma rays) to induce production of radionucleides that emit gamma radiation on decay; the decay-related gamma-ray spectrum is interpreted to determine composition of the sample (https://doi.org/10.3390/min11060617)
Photon spectrometry
Analysis of the energy distribution of photons emitted from a sample.
Physical property measurement
Various techniques used to measure the physical properties of a sample.
Pre irradiation group concentration neutron activation analysis
PRE-IRRADIATION GROUP CONCENTRATION ANALYSIS
PRE-IRRADIATION GROUP CONCENTRATION METHOD
A pre-irradiation group concentration method invovling analysis of REE relative to samarium (Sm). The sample is split in two portions. Sm and Nd content of the rock is determined by mass spectrometry isotope dilution analysis on one split. The other split is further purified for REE by cation-exchange, and is used to determine the abundance of REE relative to Sm by NAA. The REE content of the rock is found by normalization to Sm content determined by mass spectrometry in the first portion. The result are directly comparable to REE analyzed by conventional INAA. (https://doi.org/10.1016/0009-2541(90)90036-7, https://doi.org/10.1002/gj.907, http://dx.doi.org/10.1007/BF02055022)
Plasma emission spectrometry
MICROWAVE PLASMA EMISSION SPECTROMETRY
an emission spectrometry technique in which emission of photons is induced by introducing sample into a plasma. There are various techniques for generating plasma.
Plasma optical emission spectrometry
DIRECTLY COUPLED PLASMA OPTICAL EMISSION SPECTROSCOPY
PLASMA OPTICAL EMISSION SPECTROSCOPY
an emission spectrometry technique in which emission of ultraviolet or visible light is induced by introducing sample into a plasma. There are various techniques for generating plasma.
Plasma optical spectrometry
Emission, absorption, or transmission spectroscopy to analyze properties of sample atomized using a plasma. Plasma might be generated by different methods, e.g. inductive coupling, laser resonance, spark.
Plasma source mass spectrometry
ISOTOPE-DILUTION PLASMA IONISATION MULTI-COLLECTOR MASS SPECTROMETRY
PLASMA IONISATION MULTI-COLLECTOR MASS SPECTROMETRY
PLASMA-SOURCE MASS SPECTROMETRY
Mass spectrometry technique. Components: 1) sample preparation: not specified; 2) ionization: plasma; 3) mass analyzer: not specified; 4) detector: not specified. Plasma can be generated in various ways: inductive coupling, spark, lasers, microwaves.
Point counting
method to determine the proportion of an area that is covered by some objects of interest. In most cases the area is a thin section or a polished slab. The basic method is to cover the area by a grid of points. Then for each of these points, the underlying object is identified. Then the estimate for the proportion of the area covered by the type of object is based on the fraction of points assigned to that object type. ( https://en.wikipedia.org/wiki/Point_counting_(geology) ). The data are typically collected using a microscope.
Polarography
FILM POLAROGRAPHY
A type of voltammetry in which the working electrode is a unique dropping mercury electrode. Voltammetry is based on the measurement of the current that develops in an electrochemical cell under conditions where concentration polarization exists. At one time, polarography was an important tool for the determination of inorganic ions and certain organic species in aqueous solutions. Many of these analytical applications have been replaced by spectroscopic methods, and polarography became a less-important method of analysis except for certain special applications, such as the determination of molecular oxygen in solutions. (Skoog et al, p. 653, https://en.wikipedia.org/wiki/Polarography, https://unacademy.com/content/nta-ugc/study-material/pharmaceutical-analysis/polarography/)
Porosimetry
Porosimetry is an analytical technique used to determine various quantifiable aspects of a material's porous structure, such as pore diameter, total pore volume, surface area, and bulk and absolute densities. (https://en.wikipedia.org/wiki/Porosimetry)
Positive ion thermal ionization mass spectrometry
POSITIVE ION THERMAL-IONIZATION MASS SPECTROMETRY
Potentiometry
ELECTROMETRY
Technique in which the potential difference between an indicator electrode and a reference electrode is measured. Application: gas-sensing electrodes (e.g., for CO2, NH3, NOx), determination of oxygen in the gas phase (lambda probe) or ions in water solutions (pH sensitive electrodes, ion-sensitive electrodes). (Source: IUPAC; https://doi.org/10.1515/pac-2018-0109).
Prompt gamma neutron activation analysis
Neutron-induced prompt gamma-ray analysis
PROMPT-GAMMA NEUTRON ACTIVATION ANALYSIS
NAA technique based on measurement of the gamma rays emitted during irradiation of the sample. (Skoog, Holler & Crouch, p. 842)
Pyrolysis gas chromatography
Chromatography in which an analytical sample is thermally decomposed to smaller fragments before entering the column.
Pyrolysis gas chromatography flame ionization detection
Pyrolysis Gas Chromatography that uses a flame ionization detector (FID) to measure the concentration of organic species in a gas stream emerging from the column. An FID typically uses a Hydrogen/Air flame into which the sample is passed to oxidize organic molecules and produces electrically charged particles (ions). The ions are collected and produce an electrical signal which is then measured. (Source: IUPAC; https://doi.org/10.1515/pac-2017-0111)
Pyrolysis gas chromatography mass spectrometry
Pyrolysis mass spectrometry
Mass spectrometry technique in which the sample is heated to the point of decomposition and the gas phase decomposition products are characterized by mass spectrometry. (Source: IUPAC; https://doi.org/10.1351/PAC-REC-06-04-06).
Quadrupole inductively coupled plasma mass spectrometry
Mass spectrometry using a quadrupole mass analyzer. Sample preparation, atomization/ionization and detectors not specified
Quantitative analysis electron induced X-ray spectrometry
ELECTRON MICROPROBE ANALYSIS
ELECTRON MICROPROBE
FIELD EMISSION ELECTRON MICROPROBE ANALYSIS
FIELD EMISSION ELECTRON MICROPROBE
Within a given sample, once the X-ray intensities of each element of interest are "counted" in a detector at a specific beam current, the count rates are compared to those of standards containing known values of the elements of interest. Counting is typically done using wavelength-dispersive spectrometry. In turn, the X-ray intensities must be corrected for matrix effects associated with atomic number (Z), absorption (A) and fluorescence (F). This correction procedure is performed within a computer program that takes the raw counting rates of each element, compares these to standards, computes the ZAF correction (or similar type of correction) and displays the results as a function of the weight % of the oxides or elements. (https://serc.carleton.edu/research_education/geochemsheets/wds.html)
Quantitative analysis particle induced X-ray spectrometry
PARTICLE INDUCED X-RAY EMISSION MICROPROBE ANALYSIS
PARTICLE INDUCED X-RAY EMISSION MICROPROBE
Quantitative polymerase chain reaction
DNA amplification
DNA enrichment
Quantitative PCR
Polymerase chain reaction to quantify target nucleotide sequences of interest. (Source: IUPAC; https://doi.org/10.1515/iupac.90.0262, https://www.degruyter.com/database/IUPAC/entry/iupac.90.0262/html). Quantitative PCR adds two elements to the standard Polymerase Chain Reaction (PCR) process: 1)Fluorescent dye and 2) Fluorometer. These two elements turn qPCR to a measurement technique in its own right. The fluorometer detects fluorescence in real time as the thermal cycler runs, giving readings throughout the amplification process of the PCR. As a result, quantitative PCR is also called real-time PCR or RT-PCR. (https://www.thermofisher.com/blog/ask-a-scientist/what-is-qpcr/)
Quantitative reflectance imaging
Quantitative reflectance imaging system
Images acquired for a particular spectral channel [need more information]
Radiochemical neutron activation analysis
DESTRUCTIVE NEUTRON ACTIVATION ANALYSIS
RADIOANALYTICAL NEUTRON ACTIVATION
destructive activation analysis
A method of NAA in which chemical separations are applied after the irradiation to separate activities of interest from interfering activities. (https://indico.cern.ch/event/716552/sessions/310934/attachments/1848163/3033363/MonicaSisti_LRT2019.pdf slide 6, https://www.nist.gov/laboratories/tools-instruments/radiochemical-neutron-activation-analysis-rnaa; Chai et al, 2021, https://doi.org/10.1515/pac-2019-0302). Components: 1) sample irradiation 2) chemical processing 3) gamma ray spectrometry
Raman spectrometry
LASER CONFOCAL-MICRORAMAN ANALYSIS
LASER CONFOCAL-MICRORAMAN
Laser Raman Microanalysis
Raman Spectroscopy
Raman vibrational spectroscopy
Raman
Measurement principle of molecular spectroscopy based on Raman scattering. (Source: IUAPC; https://iupac.org/wp-content/uploads/2019/10/PAC-REC-19-02-03.R2_PR191002MC.pdf). Raman spectroscopy is commonly used in chemistry to provide a structural fingerprint by which molecules can be identified. This technique uses a source of monochromatic electromagnetic radiation to interact with molecular vibrations, phonons or other excitations in the analyzed sample resulting in the energy of the incident photons being shifted up or down. The light source is typically a laser in the visible, near infrared, or near ultraviolet range, although X-rays can also be used. The shift in energy from the incident source gives information about the vibrational modes in the analyzed sample. Electromagnetic radiation from the illuminated spot is collected with a lens and sent through a monochromator. Elastic scattered radiation at the wavelength corresponding to the incident excitation is filtered out, while the rest of the collected light is dispersed onto a detector.
Redox potential measurement
Redox potential is an electrical measurement that shows the tendency of a solution to transfer electrons to or from a reference electrode. From this measurement we can estimate whether the sample is aerobic, anaerobic, and whether chemical compounds such as Fe oxides or nitrate have been chemically reduced or are present in their oxidized forms. The redox potential is used to describe a system's overall reducing or oxidizing capacity. The redox potential is measured in millivolts (mV) relative to a standard hydrogen electrode and is commonly measured using a platinum electrode with a saturated calomel electrode as reference.
Resonance ionization mass spectrometry
A portion of a solid sample is vaporized by a laser or pulsed ion beam. The liberated material consists of atoms and molecules, both as neutrals and ions. The sputtered ions are usually swept away by an electric field, and one or more pulsed lasers tuned to specific resonances in the element of interest are passed through the remaining neutral cloud to affect efficient ionization of that element, while other elements and molecules are largely unaffected. The photoions are then extracted into the mass analyzer, commonly a time-of-flight analyzer.
Resonance ionization time of flight noble gas mass spectrometry
Noble gas mass spectrometry technique that atomizes and ionizes samples using laser resonance to generate a plasma, and a time-of-flight mass analyzer.
Sanger sequencing
Chain termination sequencing
Method for determining nucleotide sequence of DNA based on incorporating chain-terminating dideoxynucleotides. Note: The method is named after Frederick Sanger (1918--2013, awarded the Nobel Prize in 1958 and 1980). (Source: IUPAC; https://doi.org/10.1515/iupac.90.0262, https://www.degruyter.com/database/IUPAC/entry/iupac.90.0262/html)
Scanning transmission electron imaging
Scanning transmission electron microscopy
In STEM the electron beam is focused to a fine spot (with the typical spot size 0.05 -- 0.2 nm) which is then scanned over the sample in a raster illumination system constructed so that the sample is illuminated at each point with the beam parallel to the optical axis. (https://en.wikipedia.org/wiki/Transmission_electron_microscopy). In TEM parallel electron beams are focused perpendicular to the sample plane, in STEM the beam is focused at a large angle and is converged into a focal point. The transmitted signal is collected as a function of the beam location as it is rastered across the sample. There are multiple detectors for STEM imaging: 1) BF (bright-field) detector: small angles (0-10 mrad). These images are similar to the bright-field images obtained using TEM; 2) ADF (annular dark-field ) detector: larger angles (10-50 mrad); 3) HAADF (high-angle annular dark-field) detector: Angles greater than 50mrad. (https://chem.libretexts.org/Courses/Franklin_and_Marshall_College/Introduction_to_Materials_Characterization__CHM_412_Collaborative_Text/Electron_and_Probe_Microscopy/Transmission_electron_microscopy_(TEM)%3A_TEM_versus_STEM_and_HAADF )
Secondary electron imaging
Secondary electron microscopy
Techniques that involve bombarding a sample with an accelerated electron or ion beam to produce secondary electrons. An image is formed by scanning the beam in a raster across the sample surface and measuring the intensity (count?) of secondary electrons emitted at each sample point. Secondary electrons are a result of inelastic interactions between the excitation beam and atoms in the sample; they originate from the surface region of the sample. Secondary electron imaging can provide detailed surface information. (https://www.thermofisher.com/blog/materials/sem-signal-types-electrons-and-the-information-they-provide/)
Secondary ionization mass spectrometry
HIGH-RESOLUTION SECONDARY IONIZATION MASS SPECTROMETRY
LARGE ISOTOPE-DILUTION ION-PROBE ANALYSIS
MULTI-COLLECTOR SECONDARY IONIZATION MASS SPECTROMETRY
NANO SECONDARY ION MASS SPECTROMETRY
NANO SECONDARY IONIZATION MASS SPECTROMETRY
SECONDARY ION MASS SPECTROMETRY
Secondary Ion mass spectrometry
secondary-ion mass analyzers are based on bombarding the surface of the sample with a beam of 5- to 20-keV ions. The ion beam is formed in an ion gun in which the gaseous atoms or molecules are ionized by an electron-ionization source. The positive ions are then accelerated by applying a high dc voltage. The impact of these primary ions causes the surface layer of atoms of the sample to be stripped (sputtered) off, largely as neutral atoms. A small fraction, however, forms as positive (or negative) secondary ions that are drawn into a spectrometer for mass analysis. In secondary-ion mass analyzers, which serve for general surface analysis and for depth profiling, the primary ion-beam diameter ranges from 0.3 to 5 mm. Double-focusing, single-focusing, time-of-flight, and quadrupole spectrometers are used for mass determination. Typical transducers for SIMS are electron multipliers, Faraday cups, and imaging detectors. (Skoog, Holler & Crouch, p. 549) Measure method in which a focused beam of primary ions produces secondary ions by sputtering from a solid surface. The secondary ions are analyzed by mass spectrometry. (Source: IUPAC; https://doi.org/10.1351/PAC-REC-06-04-06)
Secondary neutral mass spectrometry
Mass spectrometer that separates the processes of emission and ionisation of sputtered particles. The sputtered neutral particles, atoms and atomic clusters are detected by a mass spectrometer after post sputtering ionisation, which can be performed by an electron beam, electron gas or laser beam. Of these, the most efficient way to ionise the emitted neutral particles is laser beam ionisation. (https://www.spectroscopyeurope.com/system/files/pdf/SNMS_21_4.pdf) Laser ionization mass nanoscope or LIMAS, is a nano-beam time-of-flight secondary neutral mass spectrometry system. The primary ion beam column is a Ga liquid metal ion source that with aberration correction optics can generate a primary ion beam down to 40 nm in diameter under a current of 100 pA with an energy of 20 keV. The sputtered neutral particles are ionized by a femtosecond laser. The ions are introduced into a multi-turn mass analyzer. This instrument would be effective for ultrahigh sensitive analysis of nanosized particles such as return samples from asteroids, comets, and planets. (Ebata, Ishihara, Uchino, Itose; http://dx.doi.org/10.1002/sia.4857.
Sector field inductively coupled plasma mass spectrometry
also called double focusing (electric and magnetic) ICP-MS. Sample in solution is nebulized, atomized and ionized in an inductively coupled plasma; ions are accelerated into a sector field analyzer; the distinguishing feature from other double focusing (electrostatic, then magnetic) high-resolution mass analyzers is not clear. The technique provides good detection capability and resolving power, useful for applications such as speciation analysis.
Seismic velocity and ultrasonic elastic constant measurement
Seismic velocities and rock ultrasonic elastic constants
The compression (p) and shear (s) wave velocities in rock may be determined using a pulse generator and p and s-wave ultrasonic transducers. The transducers are placed on opposite sides of a rock slab and the transit time is measured. (OSIRIS-REx confluence)
Shotgun method
Shot gun sequencing
Method used for determining the order of bases in long DNA using sequencing of DNA broken up randomly into numerous small segments. (Source: IUPAC; https://doi.org/10.1515/iupac.90.0262, https://www.degruyter.com/database/IUPAC/entry/iupac.90.0262/html)
Sensitive high-mass-resolution ion microprobe
SENSITIVE HIGH-MASS-RESOLUTION ION MICROPROBE ANALYSIS
SENSITIVE HIGH-MASS-RESOLUTION ION MICROPROBE
SENSITIVE HIGH-MASS-RESOLUTION ION MICROPROBE-REVERSE GEOMETRY ANALYSIS
SENSITIVE HIGH-MASS-RESOLUTION ION MICROPROBE-REVERSE GEOMETRY
Sensitive High Resolution Ion MicroProbe
SIMS analysis using a system designed to obtain a highly-focused ion excitation beam to induce sputtering from very small target areas (10 to 30 micron-diameter scale), with mass-analyzer and detector designs to maximize mass resolution. Various approaches are used, and technology is constantly evolving, for example SHRIMP-RG (Reverse Geometry), multiple ion collection systems, negative-ion stable isotope measurements.
Single crystal X-ray diffraction
X-ray crystallography
Single-crystal X-ray Diffraction is a non-destructive analytical technique which provides detailed information about the internal lattice of crystalline substances, including unit cell dimensions, bond-lengths, bond-angles, and details of site-ordering. X-ray diffraction is based on constructive interference of monochromatic X-rays and a crystalline sample. These X-rays are generated by a cathode ray tube, filtered to produce monochromatic radiation, collimated to concentrate, and directed toward the sample. The interaction of the incident rays with the sample produces constructive interference (and a diffracted ray) when conditions satisfy Bragg's Law (n*'lambda'=2d*sin(theta)). This law relates the wavelength of electromagnetic radiation to the diffraction angle and the lattice spacing in a crystalline sample. These diffracted X-rays are then detected, processed and counted. By changing the geometry of the incident rays, the orientation of the centered crystal and the detector, all possible diffraction directions of the lattice should be attained. Single-crystal diffractometers use either 3- or 4-circle goniometers. These circles refer to the four angles (2*theta, 'chi', 'phi', and 'omega') that define the relationship between the crystal lattice, the incident ray and detector. Samples are mounted on thin glass fibers which are attached to brass pins and mounted onto goniometer heads. Adjustment of the X, Y and Z orthogonal directions allows centering of the crystal within the X-ray beam. Single-crystal X-ray diffraction is most commonly used for precise determination of a unit cell, including cell dimensions and positions of atoms within the lattice. (https://serc.carleton.edu/research_education/geochemsheets/techniques/SXD.html)
Principles of Instrumental Analysis Seventh Edition
Text book used as source for detailed descriptions of methods and principles involved.
methods found during researching the vocabulary that were not included in any of the source vocabularies
General categories added to group methods found in Geo.X source vocabulary and build hierarchy
SMR add general categories to group Geo.X categories
General categories not included in source vocabularies, added to build a hierarchy of methods.
SMR add general categories
The Geo.X compilation associates methods with instrument, some of the methods are not defined in Geo.X and are added in this vocabulary
SMR add methods associated with instruments from Geo.X
Solid source mass spectrometry
ISOTOPE-DILUTION SOLID-SOURCE MASS SPECTROMETRY
SOLID-SOURCE MASS SPECTROMETRY
Technique for analysis of elements or isotopes in a solid material.
Solid state nuclear magnetic resonance spectroscopy
Solid state nuclear magnetic resonance spectrometry
Solid-state nuclear magnetic resonance (NMR) spectroscopy is an atomic-level method to determine the chemical structure, 3D structure and dynamics of solids and semi-solids. The nuclear spin interactions and the effects of magnetic fields and radiofrequency pulses on nuclear spins in solid-state NMR are the same as in liquid-state NMR spectroscopy. However, because of the orientation dependence of the nuclear spin interactions in the solid state, the majority of high-resolution solid-state NMR spectra are measured under magic-angle spinning (MAS), which has profound effects on the types of radiofrequency pulse sequences required to extract structural and dynamical information. (https://doi.org/10.1038/s43586-020-00002-1, https://en.wikipedia.org/wiki/Solid-state_nuclear_magnetic_resonance)
Spark source mass spectrometry
ISOTOPE-DILUTION MULTI-ION COUNTING SPARK-SOURCE MASS SPECTROMETRY
ISOTOPE-DILUTION SPARK-SOURCE MASS SPECTROMETRY
MULTI-ION COUNTING SPARK-SOURCE MASS SPECTROMETRY
SPARK SOURCE MASS SPECTROMETRY - ISOTOPE DILUTION
SPARK-SOURCE MASS SPECTROMETRY AND CALIBRATION WITH RELATIVE SENSITIVITY FACTOR
SPARK-SOURCE MASS SPECTROMETRY
(SSMS) a general technique for multielement and isotope trace analyses. In SSMS, the atomic constituents of a sample, housed in a vacuum chamber, are converted by a high-voltage (~30 kV), radio-frequency spark to gaseous ions for mass analysis. The gaseous positive ions formed in the spark plasma are drawn into the analyzer by a dc voltage. Because a spark source produces ions with a wide range of kinetic energies, double-focusing mass spectrometers are required for mass analysis of the ions. When electron multipliers are used with double-focusing instruments, the spectrum is scanned by varying the magnetic field of the magnetic analyzer. The use of this technique leveled off and then declined with the appearance of ICPMS and some of the other mass spectrometric methods. SSMS is still applied to samples that are not easily dissolved and analyzed by plasma methods. (Skoog, Holler, & Crouch). Mass spectrometry technique. Components: 1) sample preparation: not specified 2) ionization: spark source. NOTE: spark source systems commonly use double focusing mass analyzers.
Spectrometry
SPECTROCHEMISTRY
SPECTROGRAPHIC ANALYSIS
SPECTROGRAPHY
any of various analytical techniques in which an emission (as of particles or radiation) is dispersed according to some property (such as mass, energy, or wavelength) of the emission and the amount of dispersion is measured (https://www.merriam-webster.com/dictionary/spectrometry)
Spectrophotometry
measurement of the intensity of electromagnetic radiation as a function of frequency (or wavelength) of the radiation; radiation enters the meter through a slit and is dispersed by means of a prism. (Source: NASA; UUID: 3f7c8cc2-e3c3-4dfd-a17f-9d480f1f7179)
Spherical cell bulk thermal conductivity analysis
Technique for measuring thermal conductivity, results based on a finite element model of observation data.
apparently a new technique being developed by an OSIRIS-REx sample analysis team work group, need more information to characterize. No hits on Google.
Stepped heating carbon and nitrogen isotopic analysis
Stepped heating carbon and nitrogen isotopic compositions
Stepped combustion technique on the FINESSE highly sensitive mass spectrometric complex (a single gas extraction and purification system coupled with three mass spectrometers operating in static mode). Sample is crushed to powder and loaded in the mass spectrometer extraction system, then heated incrementally (step heating) from 200 to 1400 degree C in the presence of oxygen derived from thermal decomposition, at 930 degree C, of CuO present in a separately heated unit with an inlet into the furnace, resulting in the liberation of individual components. Carbon (in the form of CO2) and molecular nitrogen are cryogenically separated from each other before analysis. Simultaneous analysis is possible by using multiple mass spectrometers connected to a common extraction line: two magnetic sector mass spectrometers for determination of carbon isotopes and nitrogen abundance, and a quadrupole mass spectrometer for nitrogen isotopes. (https://doi.org/10.1016/S0012-821X(02)00592-7)
Structured light scanning
Determination of the three-dimensional shape of an object using projected light patterns, a camera system, and digital processing. The light source from the scanner head projects a series of parallel patterns onto the scan target. When light projects onto the object's surface, the patterns become distorted. The cameras capture these images and send them to the 3D scanning software for processing.
Surface analysis
Analytical techniques focused on characterizing the surface of a sample.
Synchroton X-ray fluorescence spectrometry
SYNCHROTON X-RAY FLUORESCENCE ANALYSIS
Synchotron X-Ray Fluorescence Analysis
Synchrotron-based X-ray Fluorescence Spectroscopy
synchrotron radiation induced X-ray fluorescence analysis
Analysis of X-ray fluorescence spectra generated by excitation using a synchrotron radiation source instead of X-ray tube as excitation source. Synchrotron radiation source has the characteristics of high intensity and high collimation. ( https://link.springer.com/chapter/10.1007/978-981-16-5328-5_6 ). Synchrotron radiation is light emitted when a beam of electrons traveling close to light speed is bent away from a straight trajectory. (https://www.radiasoft.net/blog/synchrotron-radiation-101-light-sources). It is characterized by high brightness--many orders of magnitude brighter than conventional sources--and [is highly polarized], tunable, collimated (consisting of almost parallel rays) and concentrated over a small area (https://www.iop.org/publications/iop/2011/page_47511.html#gref [page no longer accessible])
Synchrotron X-ray fluorescence tomography
X-ray flourescence spectrometery focused to extract inforamtion from inside the volume of a sample, with X-rays sourced from a synchrotron.
Temperature programmed desorption electron probe analysis
TEMPERATURE PROGRAMMED DESORPTION ELECTRON PROBE
carried out by placing a catalyst inside a reactor and pushing an inert gas into the chamber. Alternatively the sample can be located in a UHV chamber with no carrier gas. The sample is dosed with a probe gas such as CO, NH3, H2 etc. The sample is then increased in temperature at a linear ramp rate and the desorption products analysed by a mass spectrometer. This technique is powerful and effective in obtaining information about surface chemistry. (https://www.hidenanalytical.com/blog/what-temperature-programmed-desorption-tpd/)
Tensiometry
measurement of soil moisture tension in the vadose zone, typically using a tensiometer.
Thermal analysis
analysis techniques that measure the thermal properties of a sample, e.g. conductivity, specific heat.
Thermal ionization mass spectrometry
CHEMICAL ABRASION THERMAL-IONIZATION MASS SPECTROMETRY
HIGH-ABUNDANCE SENSITIVITY THERMAL IONIZATION MASS SPECTROMETRY
ISOTOPE DILUTION CHEMICAL ABRASION THERMAL-IONIZATION MASS SPECTROMETRY
ISOTOPE-DILUTION THERMAL-IONIZATION MASS SPECTROMETRY
MULTI-COLLECTOR THERMAL-IONIZATION MASS SPECTROMETRY
THERMAL IONIZATION MASS SPECTROMETRY ISOTOPE DILUTION
THERMAL-IONIZATION MASS SPECTROMETRY
Mass spectrometry technique in which sample undergoes and extraction process to concetrate analyte of interest in a solution that is then placed on a filament, loaded into the mass spectrometer instrument; filaments are heated electrically, causing evaporation and ionization of the analytes, which are then introduced to the mass analyzer. Components: 1) sample preparation: not specified; 2) ionization: thermal ionization
Thermal neutron activation analysis
method based on the measurement of the radioactivity or radiation produced in samples when they are irradiated with neutrons (Skoog, Holler & Crouch, p. 842). Thermal neutrons have energies less than epithermal neutrons in the 0.1 to 0.5 eV range (based on https://elementalanalysis.com/naa/).
Thermogravimetry analysis
THERMOGRAVIMETRIC AND DIFFERENTIAL ANALYZER
Thermogravimetric analysis
Thermogravimetric analysis is a method in which the mass of a sample is measured over time as the temperature changes. This measurement provides information about physical phenomena, such as phase transitions, absorption, adsorption and desorption; as well as chemical phenomena including chemisorptions, thermal decomposition, and solid-gas reactions (e.g., oxidation or reduction). The thermogravimetric data collected from a thermal reaction is compiled into a plot of mass or percentage of initial mass on the y axis versus either temperature or time on the x-axis. This plot can be used for materials characterization through analysis of characteristic decomposition patterns.
Hasan, F. A., Score, R. and Sears, D. W. G. (1989) : The natural thermoluminescence survey of Antarctic meteorites. A discussion of methods for reporting natural TL data. Lunar and Planetary XX. Houston, Lunar Planet. Inst., 383-384; https://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1989LPI....20..383H&db_key=AST
P.H. Benoit, ,K. Ninagawa, and D.W.G. Sears, 2000, Thermoluminescence sensitivity and thermal history of unequilibrated ordinary chondrites: Review and update: Lunar and Planetary Science XXXI, 1394.pdf; https://dsears.hosted.uark.edu//publications/pub%20by%20year/2000%20papers/benoit%20et%20al%202000c.pdf
Thermoluminescence analysis
Technique used to evaluate the degree of metamorphism for ordinary chondrites, CM, CV, and CO chondrites and eucrites, and to identify meteorites that have experience unusual radiation or thermal history. Procedure: samples pulverized to 100 mesh powders, metal removed with a hand magnet. Aliquot (typically 4 mg) placed in copper pans, their natural TL emitted light intensity measured while by heating to 500 degree C, annealing any TL effect. Sample is then given a known dose of radiation and induced TL measured by heating to 500 degree C while the intensity of light emitted is measured. Light measured using a photomultiplier (or similar radiometer) equipped with IR and red filters (possibly other filters). Measurements include TL sensitivity - the maximum intensity of light emitted normalized to a standard of Dhajala (H3.8) powder; Temperature of maximum TL light intensity ('peak temperature'); Peak width of the light intensity vs. temperature curve as full-width at half maximum; ratio of light intensity peak height at low and high temperature (generally 250 and 350 degrees C), 'equivalent dose' - the ratio of natural TL intensity to induced TL intensity (at 250 degree C), multiplied by the excitation dose to induce TL. Parameters in the experiments include the mass of sample analyzed, temperature range for heating, kind of radiometer and filters used, heating rate (count time at each temperature...), and dose of radiation to the sample after the initial heating and annealing.
Thermoluminescence dating
the determination of the time elapsed since a sample was either heated or exposed to sunlight. The method is based on three observations. 1. estimation of the ionizing radiation flux in the sample location; 2. estimation of the accumulation rate of trapped exited states in the material lattice per unit of time at a given ionizing radiation flux; and 3) measurement of emitted thermoluminescent light intensity as the sample is heated. The ionizing radiation flux at the sample site is related to exposure to sunlight (related to depth of burial), cosmic rays, and radiation due to radioactive decay of elements in the enclosing material (mostly related uranium and potassium concentration). The ionizing radiation in the sample environment creates electronic excited states in the sample that can be trapped. Exposure to light or heat can causes the electrons in these states to decay to a lower-energy state and emit photons. If the sample has been heated at some point (e.g. by firing ceramics), the accumulation of trapped electrons is reset. By measuring the intensity (total energy carried by the photons reaching a unit area) of light emited when the sample is heated, the density of these electronically excited sites can be estimated. In combination with the ambient radiation flux, and the trapped excited state accumulation rate in the material, the time interval since the sample was reset can be estimated.
Titration
TITRATION ANALYSIS
VOLUMETRIC ANALYSIS
VOLUMETRY
method to determine the concentration of an identified analyte, in which a reagent, termed the titrant or titrator, with known concentration and volume reacts with a solution of analyte (which may also be termed the titrand) to determine the analyte's concentration. The volume of titrant that reacted with the analyte is termed the titration volume. (https://en.wikipedia.org/wiki/Titration)
Total reflection X-ray fluorescence spectrometry
TOTAL REFLECTION X-RAY FLUORESCENCE ANALYSIS
total reflection X- ray fluorescence analysis
a surface elemental analysis technique often used for the ultra-trace analysis of particles, residues, and impurities on smooth surfaces. TXRF is essentially an energy dispersive XRF technique arranged in a special geometry. An incident beam impinges upon a polished flat sample carrier at angles below the critical angle of external total reflection for X-rays, resulting in the reflection of most of the excitation beam photons at this surface. Since Total Reflection angle depends on the energy of the photon, one can use this effect to eliminate the high energy photons from the excitation spectrum and minimize their contribution to the background in the measured spectra, thus making possible to achieve better detection limits. Due to this configuration, the measured spectral background in TXRF is less than in conventional XRF. This reduction results in increased signal to noise ratio. (https://www-pub.iaea.org/MTCD/publications/PDF/TCS-51/html/pdf/Section%201.pdf)
Track counting
Techniques that measure microscopic damage tracks due to radioactive decay of atoms in the sample.
Transmission electron imaging
Transmission electron microscopy
technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. Multiple operating modes based on electron imaging include conventional imaging, scanning TEM imaging (STEM), and electron diffraction. (https://en.wikipedia.org/wiki/Transmission_electron_microscopy)
Transmission spectrometry
Spectrographic techniques based on spectra of electromagnetic radiation that is transmitted through a sample.
Transmitted electron diffraction
In a transmission electron microscope, the electron beam passes through a thin film of the examined material. As it interacts with the sample, part of the beam is diffracted and part is transmitted through the sample without changing its direction. Below the sample, the beam is controlled by another set of magnetic lens and apertures. Each set of initially parallel rays is focused by the first lens Objective (optics) to a certain point in the back focal plane of the first lens, forming a spot. The location of these spots is related to the interplanar distance in the sample. Other lenses below the sample can be used to produce a magnified image of the spots for all the different directions that the electrons leave the sample, a diffraction pattern. (https://en.wikipedia.org/wiki/Electron_diffraction#In_a_transmission_electron_microscope)
Ultraviolet emission spectrometry
ULTRAVIOLET EMISSION SPECTROGRAPHY
Technique based on spectrometer analysis of light emitted in the ultraviolet frequence range.
Visible light microscopy
observation of samples at high magnification using transmitted or reflected light in human-visible part of the spectrum.
Visible, near-infrared, and mid-infrared imaging
Visible, near-infrared, and mid-infrared (VNMIR) 2D spectral raster SwRI micro-FTIR
Visualization of infrared spectra data collected at a raster of points on a sample surface by selecting particular spectral intervals normalizing and mapping the measured intensity in the interval to an image channel; gray scale image based on a single spectral interval, color image with three intervals mapped to R,G,B channels.
Voltammetry
INVERSION VOLT-AMPEROMETRY
VOLTAMETRY
Voltammetry is based on the measurement of the current that develops in an electrochemical cell under conditions where concentration polarization exists. Voltammetry comprises a group of electroanalytical methods in which information about the analyte is obtained by measuring current as a function of applied potential under conditions that promote polarization of an indicator, or working, electrode. [Skoog, Holler & Crouch, p. 653).
Wavelength dispersive electron induced X-ray Spectrometry
Wavelength-dispersive X-ray fluorescence analysis
X-rays are generated in the sample by interaction with the excitation electron beam, and are selected using an analytical crystal(s) with specific lattice spacing(s). When X-rays encounter the analytical crystal at a specific angle theta, only those X-rays that satisfy Bragg's Law are reflected and a single wavelength is passed on to the detector. The wavelength of the X-rays reflected into the detector may be varied by changing the position of the analyzing crystal relative to the sample i.e. the X-ray source-crystal distance is a linear function of the wavelength. Consequently, X-rays from only one element at a time can be measured on the spectrometer and the position of a given analytical crystal must be changed in order to adjust to a wavelength characteristic of another element. There is commonly more than a single analytical crystal in a WD spectrometer and, in the case of most EPMA instruments, there are typically multiple spectrometers with a suite of analytical crystals so that the spectrometers can reach all of the elemental wavelengths of interest and it will optimize performance in different wavelength ranges. X-rays of specific wavelengths from the analytical crystal are passed on to the X-ray detector. (https://serc.carleton.edu/research_education/geochemsheets/wds.html)
Wavelength dispersive electron induced X-ray spectrometry
Wavelength-modulation spectrometry
Wavelength-modulation spectroscopy
Laser-absorption spectroscopy (LAS) technique in which excitation laser wavelength is modulated to embed discrete frequencies in the detector signal while the nominal wavelength of the laser is scanned across a molecules absorption transition. The modulation shifts absorption information to harmonics the excitation frequency, extracted via digital lock-in filters during post-processing, and the wavelength scanning enables spectra of WMS signals to be measured. The WMS signals are then used to calculate gas conditions using calibration-free WMS models.
Wet chemistry
WET-CHEMICAL ANALYSIS
Wet chemistry is a form of analytical chemistry that uses classical methods such as observation to analyze materials. It is called wet chemistry since most analyzing is done in the liquid phase. (https://en.wikipedia.org/wiki/Wet_chemistry)
X-ray absorption near edge structure spectrometry
X-RAY ABSORPTION NEAR-EDGE STRUCTURE SPECTROSCOPY
X-ray absorption near edge structure (XANES) spectroscopy
This technique is based on the absorption of an X-ray photon, in which an electron interacts with an incident X-ray to acquire a time dependent acceleration. The electron may then be promoted from a core-orbital to an unoccupied bound or continuum state with an intensity given by Fermi's Golden Rule. By varying the energy of a monochromatized beam of incident photons, a spectrum of the absorption cross section can be generated. The probability of an excitation sharply increases when the energy of the incident photon reaches the binding energy of a core-electron. In X-ray Absorption Spectroscopy (XAS) this is referred to as an edge. XANES is a subset of XAS in which the local electronic structure is characterized by investigating the absorption cross section within 50-100 eV of an edge. The XANES region is sensitive to a wealth of electronic structure information, which may be analyzed in three sections. Before the edge, the intensity of pre-edge features is greatly affected by the coordination geometry of the central atom. At the edge, formal oxidation state may be qualitatively assigned, as the energy of the edge position is not an invariant quantity for a given element, the position shifts in accordance with electron density. Finally, coordination shells are interrogated just beyond the edge as the emitted photoelectron scatters off neighboring atoms. (https://www.cei.washington.edu/education/science-of-solar/xray-absorption-near-edge-spectroscopy-xanes/)
X-ray absorption spectrometry
In this technique, the sample is exposed to monochromatic X-rays for which the photon energy is tuned to a range where core electrons can be excited (0.1-100 keV). When the incident X-ray energy is larger than the electron binding energy, there is a sharp increase in absorption (an edge). The edge positions are related to the core electron that is excited. Each element has its own edge energy, and an element's valence can be measured even in a heterogeneous sample. There are three main regions found on a spectrum generated by XAS data which are treated as separate spectroscopic techniques: 1) absorption threshold determined by the transition to the lowest unoccupied states; 2) near-edge structure (XANES); 3) Extended X-ray absorption fine structure (EXAFS) (at energy higher than the edge). X-ray absorption spectroscopy (XAS) is used for determining the local geometric and/or electronic structure of matter. The experiment is usually performed at synchrotron radiation facilities, which provide intense and tunable X-ray beams. Samples can be in the gas phase, solutions, or solids. (https://en.wikipedia.org/wiki/X-ray_absorption_spectroscopy, https://www.bnl.gov/nsls2/userguide/lectures/lecture-4-ravel.pdf)
X-ray computed tomography
X-ray computed micro-tomography (XCMT)
2D Radiograph collected as a stack of planar surfaces by focusing X-rays at progressively greater depth throught the sample. The stack is then used for the reconstruction process to create a 3D volume.
X-ray diffraction
X-RAY DIFFRACTION SPECTROMETRY
X-ray diffraction analysis
X-ray diffraction snalysis
Measurement method using diffraction of X-radiation to obtain the spatial arrangement of atoms in a crystalline sample. X-ray diffraction is based on constructive interference of monochromatic X-rays and a crystalline sample. These X-rays are generated by a cathode ray tube, filtered to produce monochromatic radiation, collimated to concentrate, and directed toward the sample. The interaction of the incident rays with the sample produces constructive interference (and a diffracted ray) when conditions satisfy Bragg's Law (n*'lambda'=2d*sin(theta)). This law relates the wavelength of electromagnetic radiation to the diffraction angle and the lattice spacing in a crystalline sample. These diffracted X-rays are then detected, processed and counted. By changing the geometry of the incident rays, the sample, and the detector, all possible diffraction directions of the lattice should be attained.(https://serc.carleton.edu/research_education/geochemsheets/techniques/XRD.html) Copper K-a radiation (l = 0.15406 nm, E = 8.04 keV) is typically used for routine XRD. (Source: IUPAC; https://doi.org/10.1515/pac-2019-0302). Technique based on observing the scattered intensity of an X-ray beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy where the scattering is elastic and the scattering object is crystalline, so that the resulting pattern contains sharp spots analyzed by X-ray crystallography. (https://en.wikipedia.org/wiki/X-ray_scattering_techniques)
X-ray fluorescence spectrometry
Active X-Ray Spectrometer
X-RAY FLUORESCENCE ANALYSIS
X-RAY FLUORESCENCE
X-ray Fluorescence spectroscopy
X-ray fluorescence analysis
XRF Spectroscopy
Primary X-rays are used to excite (fluoresce) X-rays that are emitted from the specimen. A fused disc or pressed pellet is used for the determination of major element concentrations or trace element abundances in a bulk specimen. The X-ray detector utilizes a set of diffracting crystals specially positioned to detect one characteristic X-ray at-a-time. This sequential measurement of X-rays is termed Wavelength Dispersive Spectroscopy (WDS). Additional information available at 'http://www.nmnh.si.edu/minsci/labs/xrf.htm'. Measurement method of X-ray fluorescence used to measure amounts of elements in a material. (Source: IUPAC; https://doi.org/10.1515/pac-2019-0302)
X-ray imaging
X-RADIOGRAPHY
As X-rays pass through an object, X-rays of a particular wavelength are attentuated more or less depending on the materials through which the X-rays pass and the thickness of the material. The attenuation of X-rays passing through the object makes a 'shadow pattern' which can be captured for study on photographic film, or by a reusable phosphor screen which can be read by a digital scanner, or directly by a digital detector. The resulting X-radiographs enable visualizing features hidden below an object's surface. The different attenuation values can also be used to distinguish between materials which look the same under visible light but have different X-ray absorptions. (https://www.fieldmuseum.org/science/research/area/conserving-collections/examination-documentation/x-radiography)
X-ray composition map
COMPUTER-AIDED MICROANALYZER
image produced using composition data derived from X-ray spectra analysis at a raster of points on a sample surface. Might be based on EDS or WDS data
X-ray photoelectron spectrometery
X-RAY PHOTOELECTRON SPECTROSCOPY
Technique based on irradiation of the sample surface with monochromatic X-radiation (Skoog, Holler, Crouch p540) resulting in emission of electrons. The emitted electron energy spectra are obtained and chemical states are inferred from the measurement of the kinetic energy and the number of the ejected electrons. A typical XPS spectrum is a plot of the number of electrons detected at a specific binding energy. Each element produces a set of characteristic XPS peaks. These peaks correspond to the electron configuration of the electrons within the atoms, e.g., 1s, 2s, 2p, 3s, etc. The number of detected electrons in each peak is directly related to the amount of element within the XPS sampling volume. XPS requires high vacuum (residual gas pressure p ~ 10-6 Pa) or ultra-high vacuum (p less than 10-7 Pa) conditions. (https://en.wikipedia.org/wiki/X-ray_photoelectron_spectroscopy)
X-ray photoelectron spectrometry composition mapping
X-ray photoelectron spectroscopy (XPS) elemental/chemical maps
Technique based on irradiation of the sample surface with monochromatic X-radiation (Skoog, Holler, Crouch p540) resulting in emission of electrons. The emitted electron energy spectra are obtained and chemical states are inferred from the measurement of the kinetic energy and the number of the ejected electrons. A typical XPS spectrum is a plot of the number of electrons detected at a specific binding energy. Each element produces a set of characteristic XPS peaks. Image produced from a raster of X-ray Photoelectron Spectrometer data, with image channels mapped to 1 or three characteristic energy peaks.
X-ray powder diffraction
Powder X-ray diffraction
X-ray powder diffraction (XRD) is a rapid analytical technique primarily used for phase identification of a crystalline material and can provide information on unit cell dimensions. The analyzed material is finely ground, homogenized, and average bulk composition is determined. The geometry of an X-ray diffractometer is such that the sample rotates in the path of the collimated X-ray beam at an angle theta while the X-ray detector is mounted on an arm to collect the diffracted X-rays and rotates at an angle of 2*theta. The instrument used to maintain the angle and rotate the sample is termed a goniometer. For typical powder patterns, data is collected at 2theta from ~5degree to 70degree, angles that are preset in the X-ray scan. X-ray powder diffraction is most widely used for the identification of unknown crystalline materials (e.g. minerals, inorganic compounds). (https://serc.carleton.edu/research_education/geochemsheets/techniques/XRD.html)
X-ray spectrometry
Analysis of the energy distribution of photons in the X-ray wavelength range that are emitted from a sample.