CONTENT OF trans, trans-MUCONIC, HIPPURIC, MANDELIC AND PHENYLGLYOXYLIC ACIDS METHYL ESTERS IN BIOLOGICAL SAMPLES

摘要

The present study concerns the development of gas chromatographic method for the quantitative determination of trans, trans-muconic (MA), hippuric (HA), mandelic (MdA) and phenylglyoxylic (PgA) acids methyl esters in biological specimens. The liquid-liquid extraction with ethyl acetate is employed to obtain acids from urine sample and subsequent derivatisation with a diazomethane solution. The created method is validated for linearity, accuracy, sensitivity, within-laboratory reproducibility and uncertainty. The detection limit for each acid methyl esters is determined experimentally. The average recovery is 96.8%. The relative expanded uncertainty obtained for all acids methyl esters is equal to 3.0% or less. The proposed method is applied to determine biomarkers in urine samples from the occupationally exposed subjects working in petroleum refineries plants. All urine samples, presented in our study give indications that they do not contain simultaneously all investigated biomarkers.