Armbruster, Michael R. published the artcileIsobaric 4-Plex Tagging for Absolute Quantitation of Biological Acids in Diabetic Urine Using Capillary LC-MS/MS, Safety of 2-Hydroxy-2-phenylacetic acid, the publication is ACS Measurement Science Au (2022), 2(3), 287-295, database is CAplus and MEDLINE.
Isobaric labeling in mass spectrometry enables multiplexed absolute quantitation and high throughput, while minimizing full scan spectral complexity. Here, we use 4-plex isobaric labeling with a fixed pos. charge tag to improve quantitation and throughput for polar carboxylic acid metabolites. The isobaric tag uses an isotope-encoded neutral loss to create mass-dependent reporters spaced 2 Da apart and was validated for both single- and double-tagged analytes. Tags were synthesized inhouse using deuterated formaldehyde and Me iodide in a total of four steps, producing cost-effective multiplexing. No chromatog. deuterium shifts were observed for single- or double-tagged analytes, producing consistent reporter ratios across each peak. Perfluoropentanoic acid was added to the sample to drastically increase retention of double-tagged analytes on a C18 column. Excess tag was scavenged and extracted using hexadecyl chloroformate after reaction completion. This allowed for removal of excess tag that typically causes ion suppression and column overloading. A total of 54 organic acids were investigated, producing an average linearity of 0.993, retention time relative standard deviation (RSD) of 0.58%, and intensity RSD of 12.1%. This method was used for absolute quantitation of acid metabolites comparing control and type 1 diabetic urine. Absolute quantitation of organic acids was achieved by using one isobaric lane for standards, thereby allowing for anal. of six urine samples in two injections. Quantified acids showed good agreement with previous work, and six significant changes were found. Overall, this method demonstrated 4-plex absolute quantitation of acids in a complex biol. sample.
ACS Measurement Science Au published new progress about 90-64-2. 90-64-2 belongs to alcohols-buliding-blocks, auxiliary class Carboxylic acid,Benzene,Alcohol,Natural product, name is 2-Hydroxy-2-phenylacetic acid, and the molecular formula is C8H8O3, Safety of 2-Hydroxy-2-phenylacetic acid.
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