[Study on the method of detection of benzene exposure biomarkers by solid phase extraction-gas chromatography-tandem...

Objective: A gas chromatography-tandem mass spectrometry detection method for benzene and its metabolites was established to provide methodological support and theoretical basis for the study of benzene toxicity mechanism. Methods: In August 2019 to March 2020, the animal model of containing high concentration of benzene by inhalation of poison through the respiratory tract of mice was established, taken the blood of mice after dyeing the poison, and the HLB solid phase extraction method was used to extract and purify the samples. The gas chromatography-tandem mass spectrometry detection method was used to qualitative and quantitative analysis of the target substances. After separated by HP-17MS capillary chromatographic column, the compounds were ionized with EI ion source, mass spectrometry detection was carried out by selective ion scanning method (SIM) , and quantification was carried out by external standard curve method. Results: Benzene and its metabolites (phenol, catechol, hydroquinone and m-trihydroxybenzene) in blood could be effectively separated and quasi deterministic and quantitative by this method. The regression equations and correlation coefficients of this method for detecting benzene and its metabolites were: benzene: y=3252.1x+1540, r=0.9993; phenol: y=2046.5x+1423, r=0.9991; catechol: y=1853.9x+945, r=0.9993; hydroquinone: y=1891.5x+840, r=0.9992; m-trihydroxybenzene: y=1052.4x+655, r=0.9991. The detection limits for benzene, phenol, catechol, hydroquinone and m-trihydroxybenzene were 0.03, 0.03, 0.05, 0.05 and 0.10 μg/g, respectively. And the lower limits of quantification were 0.10, 0.10, 0.15, 0.15 and 0.30 μg/g, respectively. The intra-assay precision interval was 2.64%-10.06%, the inter-assay precision interval was 1.37%-10.17%, and the spike recovery rate was 89.8%-102.3%. This method could be used to quantitatively detect benzene, phenol, catechol, hydroquinone and m-trihydroxybenzene in the blood of benzene-infected mice. Conclusion: Solid phase extraction-gas chromatography-mass spectrometry can be used for qualitative and quantitative detection of benzene and its metabolites (phenol, catechol, hydroquinone and m-trihydroxybenzene) accurately.