DETERMINATION OF 2,5-HEXANEDIONE, A METABOLITE OF N-HEXANE, IN URINE - EVALUATION AND APPLICATION OF 3 ANALYTICAL METHODS

Three methods for the determination of 2,5-hexanedione (2,5-HD) in uri ne were compared in order to assess their applicability for toxicokine tic studies and biological monitoring of occupational exposure to n-he xane. Two of them were based on derivatization, followed by gas chroma tography and electron-capture detection. Of these two, one is a modifi cation of the other, already published, method. The third one involves direct extraction of 2,5-HD followed by gas chromatography and flame- ionization detection. To determine 2,5-HD in urine of workers occupati onally exposed to n-hexane, the most straightforward method, direct ex traction of 2,5-HD from urine, has been proven to be the most suitable . However, in case of very low concentrations of 2,5-HD in urine, or a nalysis of small samples of blood, e.g. in kinetic studies, it is nece ssary to use a more sensitive procedure. The sensitivity of the method s based on the derivatization of 2,5-HD followed by electron-capture d etection, was, as expected, much higher in terms of analytical reliabi lity. By using these methods, however, precautions are necessary to av oid a matrix effect.