title: Keto acid profiling analysis as ethoxime/tert-butyldimethylsilyl derivatives by gas chromatography-mass spectrometry.
abstract: Organic acids, including keto acids, are key intermediates of central pathways in cellular metabolism. In this study, a comprehensive and reliable method was developed and optimized for the simultaneous measurement of 17 keto acids in various biological samples. The keto acids were converted to solvent extractable forms by ethoximation followed by tert-butyldimethylsilylation for direct analysis by gas chromatography-mass spectrometry in selected ion monitoring mode. The proposed method was precise (0.05-8.3, % RSD) and accurate (-10.5 to 5.3, % RE) with low limit of detection (0.01-0.5ng/mL) and good linearity (r>0.995) in the range of 0.01-5.0μg/mL. This was suitable for profiling analysis of targeted keto acids in human plasma, urine and rat brain tissue.
authors.affiliation: Department of Molecular Science and Technology, Ajou University, Suwon 443-721, Republic of Korea.
authors.forename: Duc-Toan
authors.initials: DT
authors.lastname: Nguyen
authors.forename: Gwang
authors.initials: G
authors.lastname: Lee
authors.forename: Man-Jeong
authors.initials: MJ
authors.lastname: Paik
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007651:Keto Acids / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000652:urine; D057230:Limit of Detection; D016014:Linear Models; D010091:Oximes / Q000737:chemistry*; D051381:Rats; D015203:Reproducibility of Results; D012821:Silanes / Q000737:chemistry*; D013696:Temperature
chemical_list: D007651:Keto Acids; D010091:Oximes; D012821:Silanes; C103256:tert-butyldimethylsilane