The objective of the study was to validate a new and simple method to determine MOCA in the urine of exposed workers.
The separation, identification and quantification of urinary MOCA were performed in spiked urines by a sensitive and practical high-performance liquid chromatography (HPLC) method and applied to urine samples of 11 workers occupationally exposed to MOCA ; the postshift urinary levels of MOCA in their urine samples with and without hydrolysis, « total » and « free » MOCA respectively, were determined.
In addition, we investigated the use of citric or sulfamic acid as preservatives of urine samples.
The « total » and « free » MOCA were extracted with isooctane from hydrolysed and nonhydrolysed 20-ml urine samples respectively.
After evaporation, the residue was dissolved in 4 ml of 2. 10-2 M aqueous hydrochloric acid and analysed by an isocratic HPLC system using both ultraviolet (UV) detection at 244 nm and electrochemical detection working in oxidation mode (0.9 V) with an Ag/AgCl reference electrode.
Mobile phase (50% acetonitrile in water containing 0.4% acetate buffer solution pH=4.6) was used to complete the 20-min analysis. « Free » and « total » MOCA were chromatographed on a reversed-phase C8 column (5 mum ; 250 mm x 4 mm).
The standard curve of MOCA was linear over the range 5-500 mug/l in human urine.
The detection limit was 1 mug/l for a 20-mul injection volume ; the repeatability ranged from 5.6 to 1. (...)
Mots-clés Pascal : Amine, Composé aromatique, Exposition professionnelle, Médecine travail, Homme, Surveillance biologique, Urine, Liquide biologique, Analyse quantitative, Chromatographie HPLC, Analyse électrochimique, 4,4p-Méthylènedianiline(2,2p-dichloro)
Mots-clés Pascal anglais : Amine, Aromatic compound, Occupational exposure, Occupational medicine, Human, Biological monitoring, Urine, Biological fluid, Quantitative analysis, HPLC chromatography, Electrochemical analysis
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0436299
Code Inist : 002B03L06. Création : 22/03/2000.