title: An improved method for the simultaneous determination of mandelic and phenylglyoxylic acids by gas chromatography.
abstract: We present a method that permits the simultaneous analysis of mandelic acid (MA) and phenylglyoxylic acid (PGA) in the urine of workers occupationally exposed to styrene. The method consists of urine extraction in acid medium with chloroform and the subsequent formation of the respective methyl esters. The samples were submitted to gas chromatography using a glass column packed with 10% SP-1000. Recoveries of 66.7% and 95.4% were obtained for MA and PGA, respectively, with limits of quantitation of 0.03 g/L for MA and 0.02 g/L for PGA. The method proved to be precise in terms of both intra-assay and interassay analysis, with coefficients of variation less than 10%.
authors.affiliation: Department of Clinical, Toxicological, and Food Science Analyses-Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: V L
authors.initials: VL
authors.lastname: Lanchote
authors.forename: A C
authors.initials: AC
authors.lastname: dos Santos
authors.forename: R H
authors.initials: RH
authors.lastname: Queiroz
authors.forename: E
authors.initials: E
authors.lastname: Tozatto
authors.forename: D
authors.initials: D
authors.lastname: Carvalho
mesh_terms: D002849:Chromatography, Gas / Q000379:methods; D006038:Glyoxylates / Q000652:urine*; D006801:Humans; D007202:Indicators and Reagents; D008333:Mandelic Acids / Q000652:urine*; D016273:Occupational Exposure / Q000032:analysis*; D013343:Styrenes
chemical_list: D006038:Glyoxylates; D007202:Indicators and Reagents; D008333:Mandelic Acids; D013343:Styrenes; C012482:phenylglyoxylic acid; C037938:mandelic acid