[Determination of seven urinary metabolites of benzene, toluene and xylene by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry].

Objective: To develop a method using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to determine the urinary metabolites of benzene, toluene and xylene. The selected metabolites are S-phenylmercapturic acid (S-PMA) , trans, trans-muconic acid (t, t-MA) , 8-hydroxy-2 deoxyguanosine (8-OHdG) , hippuric acid (HA) , 2-methylhippuric acid (2-MHA) , 3-methylhippuric acid (3-MHA) and 4-methylhippuric acid (4-MHA) . Methods: The urine sample was pretreated using methanol to precipitate the proteins. HSS T3 chromatographic column was used to separate the metabolites. The mass spectrometric acquisition was carried out using multiple reaction monitoring (MRM) after ionization with ESI source. External standard method was used for quantification. Results: All the standard curves showed good linear relation, and r of the seven metabolites was all above 0.999. The detection limits and quantitative limits of the seven metabolites were 0.01-500 ng/ml and 0.02-1 000 ng/ml (based on the actual dilution ratio) , respectively. The average spiked recoveries of four loadings ranged from 85.8% to 109.9%. The intra-day and inter-day precisions were 0.2%-4.5% and 0.6%-9.5%, respectively. The samples can be kept for at least 14 days at both 4 ℃ and -20 ℃. Conclusion: This method is simple, rapid and highly sensitive with low cost, and its accuracy, precision and stability can meet the daily test requirements. It can be applied for the determination of urinary S-PMA, t, t-MA, 8-OHdG, HA, 2-MHA, 3-MHA and 4-MHA for the occupational population exposed to benzene, toluene and xylene.目的： 建立尿中苯、甲苯及二甲苯的生物标志物苯巯基尿酸（S-PMA）、反-反式粘糠酸（t，t-MA）、8-羟基-2-脱氧鸟苷（8-OHdG）、马尿酸（HA）、2-甲基马尿酸（2-MHA）、3-甲基马尿酸（3-MHA）及4-甲基马尿酸（4-MHA）的超高效液相色谱-三重四极杆质谱检测方法。 方法： 尿样采用甲醇沉淀蛋白法，经稀释后进样，通过HSS T3色谱柱对待测化合物进行分离；经电喷雾电离源离子化，采用多反应监测模式进行检测；待测化合物通过外标法进行定量。 结果： 该方法线性良好，r>0.999；方法的检出限和定量限分别为0.01~500和0.02~1 000 ng/ml（以尿样稀释倍数计）；平均加标回收率为85.8%~109.9%；批内和批间精密度分别为0.2%~4.5%和0.6%~9.5%；在4 ℃和-20 ℃条件下均可保存至少14 d。 结论： 该方法简便经济，灵敏度高，准确度、精密度和稳定性均可满足日常测试要求，适用于职业接触苯、甲苯及二甲苯人群尿中S-PMA、t，t-MA、8-OHdG、HA、2-MHA、3-MHA及4-MHA的测定。.