RESUMO
2,5-Hexanedione (2,5-HD) is the most important metabolite of n-hexane and methyl ethyl ketone in human urine. Urinary 2,5-HD is used as a biomarker for biological monitoring of workers exposed to n-hexane. A simple method using headspace solid-phase microextraction (HS-SPME) and gas chromatography (GC) equipped with a flame-ionization detector (FID) was developed. The parameters that affect the HS-SPME-GC-FID process were optimized (i.e., fiber coating, sample volume, adsorption and heating time, salt addition, and extraction temperature). The assay presented linearity in the range of 0.075 to 20.0 mg/L, precision (coefficient of variation < 7.0%), and detection limit of 0.025 mg/L for 2,5-HD in urine. The method was successfully applied to the analysis of 2,5-HD in urine samples from eight workers occupationally exposed to n-hexane in shoemaker's glue.
Assuntos
Adesivos/metabolismo , Cromatografia Gasosa , Monitoramento Ambiental/métodos , Hexanos/metabolismo , Hexanonas/urina , Exposição Ocupacional , Microextração em Fase Sólida , Biomarcadores/urina , Biotransformação , Calibragem , Cromatografia Gasosa/normas , Monitoramento Ambiental/normas , Ionização de Chama , Humanos , Reprodutibilidade dos Testes , Sapatos , Microextração em Fase Sólida/normasRESUMO
Urinary 2,5-hexanedione (2,5-HD) is used as a biomarker for biological monitoring of workers exposed to n-hexane. The purpose of this study was to compare two types of treatment of urine samples during clean-up (with and without acidic hydrolysis) and to study the exposure situation of workers exposed to n-hexane during shoe manufacturing. There, various glues containing n-hexane are used. Quantification of 2,5-HD was carried out by gas chromatography and flame ionization detection (GC-FID). Fifty-two urine samples taken from workers of seven shoe factories were analyzed. Thirty-four persons from the administrative staff of the same factories served as controls. They were not known to be exposed to n-hexane. The samples treated with acidic hydrolysis showed levels (average 0.94 mg/l) approximately 10 times higher than samples without acidic hydrolysis (0.09 mg/l). The difference is predominantly caused by the conversion of other metabolites of n-hexane (e.g. 4,5-dihydroxy-2-hexanone) to 2,5-HD in the presence of acids. Our results also show, that exposure to n-hexane is different between various industries. Levels of 2,5-HD in urine are predominantly dependent on the type of operation (how the glue is applied on the leather during shoe manufacturing). Simple measures, e.g. using a glue handgun instead of a paintbrush significantly decreased exposure to n-hexane.