MS Description
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Extraction procedures<br />
All meta … Extraction procedures<br />
All metabolite extraction procedures were kept on ice, and the quantities for sample aliquots were 25 μL for blood plasma, 5 x 10^6 for cells, 5 mg for tissues, and 2 mL for algae cultures. Metabolites were extracted with 1,000 μL of degassed acetonitrile:isopropanol:water (3:3:2, v/v/v) and then homogenized, centrifuged, decanted, and evaporated. Extracts were cleaned with 500 μL of degassed acetonitrile:water (1:1, v/v) to remove triglycerides and membrane lipids, and evaporated again. For GC-MS analysis, internal standard C8–C30 fatty acid methyl esters were added to determine the retention index. The dried samples were derivatized with 10 μL of methoxyamine hydrochloride (or ethoxyamine hydrochloride) in pyridine and subsequently by 90 μL of MSTFA (or MSTFA-d9) for trimethylsilylation of acidic protons.<br />
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The biological sample was NIST standard human plasma; analysis procedures were done according to the “Agilent GC-Quadrupole MS” protocol from a previous report. upole MS” protocol from a previous report.
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