Journal of the Brazilian Chemical Society
Print version ISSN 0103-5053
PAIVA, Maria José N. de; MARTINS, Isarita and SIQUEIRA, Maria Elisa P. B. de. Analysis of ortho-cresol in urine by solid phase microextraction-capillary gas chromatography. J. Braz. Chem. Soc. [online]. 2007, vol.18, n.5, pp. 1034-1039. ISSN 0103-5053. http://dx.doi.org/10.1590/S0103-50532007000500024.
The object of the present study was the development of method for the determination of urinary ortho-cresol using solid-phase microextraction (SPME), followed by capillary gas chromatography-flame ionization detection (GC/FID). After optimization of the SPME variables and validation of the method, it was applied to analysis of o-cresol in urine collected from 27 workers exposed to solvents in automotive repair shops. The maximum extraction efficiency was obtained using fiber of carbowax-divinylbenzene (CW/DVB), 70 µm, immerged 20 min in acid hydrolysed urine added with 3 g Na2SO4 at pH 7.0 and under magnetic stirring. The method showed linearity between 0.1 to 1.5 mg L-1, LOQ of 0.1 mg L-1, precision between 6.8 to 7.8% CV. Mean o-cresol in urine from exposed workers was 0.35 ± 0.23 mg L-1. The SPME-GC/FID method is fast, simple and can be applied to the occupational toluene biomonitoring.
Keywords : urinary ortho-cresol; SPME; biomonitoring; toluene.