Comparison Log
2026-02-01 09:37:47.807225
mwtab Python Library Version: 2.0.0
Source:      https://www.metabolomicsworkbench.org/rest/study/analysis_id/AN007549/mwtab/...
Study ID:    ST004502
Analysis ID: AN007549
Status:      Inconsistent

Sections "SAMPLEPREP" contain missmatched items: {'SAMPLEPREP_SUMMARY': ['"SRM Plasma: NIST SRM 1950 and 8231 were provided by the National Institute of Standards and Technology (Schock, Tracey B. (Fed) tracey.johnston@nist.gov). Samples were stored at -80°C. One whole tube of each SRM plasma was thawed with occasional mixing, and then 200 µL aliquots were transferred to 1.5-mL Eppendorf tubes containing 800 uL ice-cold 1:1:1 mixture of methanol:acetonitrile:acetone (“MAA”). The tubes were stored at -20°C for 1 h, and centrifuged at 12,000 x g, 4°C, for 10 min. Supernatant from all Eppendorf tubes of each SRM plasma were pooled and thoroughly mixed to get two pooled SRM plasma samples. This solution represents a relative concentration of 1. Yeast: Unlabelled and U13C labelled yeast sample was resuspended in 2 mL Water following manufacturer’s instruction (Cambridge Isotope Laboratories), vigorously hand mixed for 30 s, vortex mixed on max speed for 30 s, transferred to 2-mL Eppendorf tubes, and centrifuged at 12,000 x g, 4°C, for 10 min. Then supernatant was diluted 2x with water. This solution represents a relative concentration of 1. To avoid freeze-thaw the yeast extract supernatant, the extract was prepared just before final mixing. Authentic standards: Ninety-six individual pure authentic standards were obtained from Chromadex (Longmont, Colorado, US). Compounds were selected to have low probability of being encountered in the samples at the spiked concentration, and designed to reflect the molecular weight and hydrophobicity distribution of metabolites found in the Human Metabolome Database. The standards selected (all compounds with ID starting with ‘st’) can be found in Appendix 1. 4mix: Individual standard stock solutions were prepared by dissolving 1-2 mg (accurately weighed) of dry standard in appropriate solvents (Appendix 2) to achieve concentration in the range of 100-1000 ug/mL. 4mix standard mixtures were prepared by mixing 200 µL of individual standard according to Appendix 2. 96mix: In a clean, methanol washed (and dried) 20-mL glass vial, 4mix solutions were added to 9.26 mL of methanol according the volumes as described in Appendix 2, to get 96mix-spike A (10 mL total) and 96mix-spike B (10 mL total). These solutions represent a relative concentration of 1. Absolute concentrations are also provided for each individual compound in each sample. Solutions of Spike A and Spike B were stored at -80°C. Internal Standard: Twenty-one internal standards were obtained from Cambrige Isotope Labs (Andover, Massachusettes, USA). Individual internal standard stock solutions were prepared by dissolving 1-2 mg (accurately weighed) dry standard in appropriate solvents (Appendix 1). The final internal standard solution was generated by mixing stock solutions and diluting with methanol. The internal standards solutions were prepared as described in Appendix 1 (all compounds with ID starting with ‘is’). The solutions were stored at -80°C. Preparation Blank: Methanol (240 uL) used in the above sample prep was mixed with 60 µL of IS. Solvent Blank: The following solvents that were used in the above sample prep, 300 µL of MMA, 300 µL of water, 300 µL of methanol, were mixed without the addition of IS. Generation of Benchmark Samples: All samples were prepared by mixing plasma extracts, yeast extracts, spikeA, spikeB, and IS according to the volume ratios presented in Appendix 3 into respective glass autosampler vials (2 mL). When the volume of assigned solutions was greater than 1.8 mL, reagents were added sequentially with intermittent removal of solvents under nitrogen. The full volume of added reagent described in Appendix 3 was dried in the vial, and resuspending in 1500 µL of Methanol and vortex mixed to resuspend solutes. Of these 1500 µL, 600 µL were transferred to a Washington University vial, and 800 µL were transferred to a new CSU vial. Solvent was again evaporated under nitrogen in preparation for shipping, and stored in -80°C until shipment. Samples were shipped overnight on dry ice to Washington University from CSU. Samples were reconstituted in absolute methanol prior to analysis, at equal concentration to the original aliquot volume prior to drying.', 'SRM Plasma: NIST SRM 1950 and 8231 were provided by the National Institute of Standards and Technology (Schock, Tracey B. (Fed) tracey.johnston@nist.gov). Samples were stored at -80°C. One whole tube of each SRM plasma was thawed with occasional mixing, and then 200 µL aliquots were transferred to 1.5-mL Eppendorf tubes containing 800 uL ice-cold 1:1:1 mixture of methanol:acetonitrile:acetone (“MAA”). The tubes were stored at -20°C for 1 h, and centrifuged at 12,000 x g, 4°C, for 10 min. Supernatant from all Eppendorf tubes of each SRM plasma were pooled and thoroughly mixed to get two pooled SRM plasma samples. This solution represents a relative concentration of 1. Yeast: Unlabelled and U13C labelled yeast sample was resuspended in 2 mL Water following manufacturer’s instruction (Cambridge Isotope Laboratories), vigorously hand mixed for 30 s, vortex mixed on max speed for 30 s, transferred to 2-mL Eppendorf tubes, and centrifuged at 12,000 x g, 4°C, for 10 min. Then supernatant was diluted 2x with water. This solution represents a relative concentration of 1. To avoid freeze-thaw the yeast extract supernatant, the extract was prepared just before final mixing. Authentic standards: Ninety-six individual pure authentic standards were obtained from Chromadex (Longmont, Colorado, US). Compounds were selected to have low probability of being encountered in the samples at the spiked concentration, and designed to reflect the molecular weight and hydrophobicity distribution of metabolites found in the Human Metabolome Database. The standards selected (all compounds with ID starting with ‘st’) can be found in Appendix 1. 4mix: Individual standard stock solutions were prepared by dissolving 1-2 mg (accurately weighed) of dry standard in appropriate solvents (Appendix 2) to achieve concentration in the range of 100-1000 ug/mL. 4mix standard mixtures were prepared by mixing 200 µL of individual standard according to Appendix 2. 96mix: In a clean, methanol washed (and dried) 20-mL glass vial, 4mix solutions were added to 9.26 mL of methanol according the volumes as described in Appendix 2, to get 96mix-spike A (10 mL total) and 96mix-spike B (10 mL total). These solutions represent a relative concentration of 1. Absolute concentrations are also provided for each individual compound in each sample. Solutions of Spike A and Spike B were stored at -80°C. Internal Standard: Twenty-one internal standards were obtained from Cambrige Isotope Labs (Andover, Massachusettes, USA). Individual internal standard stock solutions were prepared by dissolving 1-2 mg (accurately weighed) dry standard in appropriate solvents (Appendix 1). The final internal standard solution was generated by mixing stock solutions and diluting with methanol. The internal standards solutions were prepared as described in Appendix 1 (all compounds with ID starting with ‘is’). The solutions were stored at -80°C. Preparation Blank: Methanol (240 uL) used in the above sample prep was mixed with 60 µL of IS. Solvent Blank: The following solvents that were used in the above sample prep, 300 µL of MMA, 300 µL of water, 300 µL of methanol, were mixed without the addition of IS. Generation of Benchmark Samples: All samples were prepared by mixing plasma extracts, yeast extracts, spikeA, spikeB, and IS according to the volume ratios presented in Appendix 3 into respective glass autosampler vials (2 mL). When the volume of assigned solutions was greater than 1.8 mL, reagents were added sequentially with intermittent removal of solvents under nitrogen. The full volume of added reagent described in Appendix 3 was dried in the vial, and resuspending in 1500 µL of Methanol and vortex mixed to resuspend solutes. Of these 1500 µL, 600 µL were transferred to a Washington University vial, and 800 µL were transferred to a new CSU vial. Solvent was again evaporated under nitrogen in preparation for shipping, and stored in -80°C until shipment. Samples were shipped overnight on dry ice to Washington University from CSU. Samples were reconstituted in absolute methanol prior to analysis, at equal concentration to the original aliquot volume prior to drying.']}
Sections "PROJECT" contain missmatched items: {'FUNDING_SOURCE': ["This research was supported by the NPH Common Fund's Metabolomics Program (U01CA235507-01, PI: Xiuxia Du).", "This research was supported by the NPH Common Fund''s Metabolomics Program (U01CA235507-01, PI: Xiuxia Du)."]}