In order to analyse metabolites in urine after trimethylbenzene (TMB) exposure a method based on high-performance liquid chromatography (HPLC) for determination of the six dimethylhippuric acids (2,3-DMHA, 2,6-DMHA, 2,5-DMHA, 2,4-DMHA, 3,4-DMHA and 3,5-DMHA) in urine has been developed.
In contrast to earlier published methods, the present method allows detection of all possible isomers of DMHA in a single analysis.
The DMHAs were extracted from urine with dichloromethane.
After evaporation, the residue was dissolved in mobile phase and analysed by a stepwise gradient HPLC system with ultraviolet (UV) detection at 225 nm.
Mobile phase A (1.25% acetonitrile and 0.3% acetic acid in water) was used up to a retention time of 59.5 min and mobile phase B (5% acetonitrile in water containing 0.3% acetic acid) was used for completion of the analysis at approximately 90 min.
The DMHA isomers were chromatographed on a reversed phase Radial-Pak C18 column (4 mum ; 100 mm x 5 mm inner diameter).
The detection limit for the six isomers was 1.5 mug/ml (range 0.5-3.4,100 mul injection volume).
The precision of the method was 4.2% relative standard deviation (range 3.8-4.4 ; 100 mug/ml).
Standard curves of the DMHAs were linear over the interval 10-500 mug/ml in human urine.
Individual DMHAs or the sum of DMHA isomers may be used as biological indicators of occupational exposure to TMBs.
Mots-clés Pascal : Métabolite, Urine, Analyse quantitative, Chromatographie HPLC, Surveillance biologique, Exposition professionnelle, Homme, Liquide biologique, Isomère, Médecine travail, Benzène(triméthyl)
Mots-clés Pascal anglais : Metabolite, Urine, Quantitative analysis, HPLC chromatography, Biological monitoring, Occupational exposure, Human, Biological fluid, Isomer, Occupational medicine
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0062527
Code Inist : 002B03L06. Création : 21/05/1997.