Naslov
Determination of mandelic acid enantiomers in urine by gas chromatography and electron capture or flame ionization detection

Autori
Kežić, Sanja ; Jakaša, Ivone ; Wenker, Mira

Izvornik
Journal of Chromatography B - Biomedical Sciences and Applications (0378-4347) 738 (2000), 1; 39-46

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Mandelic acid; Enantiomer separation

Sažetak
A sensitive and stereospecific GC method was developed for the analysis of R- and S-enantiomers of mandelic acid (MA) in urine, using a chiral CP Chirasil-Dex-CB column. The enantiomers of MA were derivatised with isopropanol into their corresponding isopropyl esters and determined either directly with flame ionisation detection (FID) or after subsequent derivatisation of a hydroxy group with pentafluoropropionic anhydride with electron-capture detection (ECD). Both derivatisation steps proceeded with negligible inversion of enantiomers (<1 %). The limit of detection of the FID determination was 8 and 5 mg/L for R-MA and S-MA, respectively and of the ECD determination 1 mg/L for both enantiomers. Repeatability (within-day precision) and reproducibility (day-to-day precision) was for both enantiomers below 7.5 % for the FID and below 5.8 % for the ECD analysis. The method was applied to urine of volunteers exposed to 105 and 420 mg styrene/m3 air. In the urine of the exposed volunteers, the S-enantiomer showed higher excretion compared to that of the R-enantiomer, with marked interindividual differences in excretion of both enantiomers.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA