Determination of benzene, toluene, ethylbenzene, p-, m-, o-xylene, and n-butyl acetate in urine by a validated gas chromatography method: Application to an occupational monitoring study

This study was aimed to determine occupational and non-occupational exposure to benzene, toluene p-m-o-xylene (BTEXs) and butyl-acetate (nBA). The aim of this work was to develop a simple, sensitive, and reliable chromatographic method using urine, a non-invasive human sample. The method was applied to samples collected from furniture spray workers (n=53) who are at risk of exposure to BTEXs and nBA and office workers (n=51) who have no known exposure risk. Method validation tests, include the sensitivity (LOD <= 0.018 ng/mL), precision (RSD <= 4.1), accuracy (RE% (-3.9)-4.7), recovery (96.1-103.8%) and linearity (r(2)>= 0.999). Urinary benzene (1.77 vs 1.23 ng/mL, exposed-control, respectively), toluene (51.22 vs 0.77 ng/mt), ethylbenzene (9.25 vs 6.69 ng/mt), para-xylene (1.73 vs 0.62 ng/mt), meta-xylene (2.58 vs 1.20 ng/mt), ortho-xylene (1.61 vs 0.88 ng/ mL), and butyl acetate (33.14 vs 1.63 ng/mL) concentrations were determined in the exposed and control group samples. Significant correlations were found between benzene (p=0.286*), ethylbenzene (p=0.552***) and o-xylene (p=0.292*) levels and smoking status in samples belonging to the control group. The occupationally-exposure-risk group samples have significantly higher BTEXs and nBA concentrations than the control (p<0.001). It was determined that smoking was a significantly effective factor in exposure to benzene, ethylbenzene and o-xylene in the control group.