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目的建立一种灵敏、可靠的气相色谱-质谱联用(GC-MS)测定方法,以检测人尿中拟除虫菊酯类农药的主要代谢产物3-苯氧基苯甲酸(3-PBA)的浓度。方法尿液中加入内标2-苯氧基-苯甲酸(2PBA),以正己烷为提取溶剂,在酸性条件下采用液一液萃取法提取目标化合物3-PBA,然后在碱性条件下去除溶于有机相的杂质,目标化合物则进入水相,再在酸性条件下以正己烷重新提取水相中的目标化合物,氮吹干正己烷后,用N,(特丁基二甲基硅烷基)-N-甲基三氟乙酰胺(MTBSTFA)对目标化合物进行衍生化处理,利用GC-MS对衍生化产物进行分离检测,以分析尿液中3-PBA的浓度。结果尿液中3-PBA在0.05～30μg/L浓度范围内呈良好线性,相关系数为0.9974;最低检测限为0.01μg/L,日内相对标准偏差(RSD)为2.4%～3.8%,日间RSD为8.7%～10.8%;相对回收率为94.3%～120.6%。结论该方法经济、可靠,且灵敏度比其他类似方法高,可以快速准确地检测人尿液中拟除虫菊酯类农药主要代谢产物3-PBA浓度,从而预测该类农药在中国普通人群中的暴露水平,并为拟除虫菊酯类农药的安全性评价提供依据。
Objective To establish a sensitive and reliable method for the determination of 3-phenoxybenzoic acid (3-PBA), a major metabolite of pyrethroid pesticides in human urine by gas chromatography-mass spectrometry (GC-MS) . Methods 2-phenoxy-benzoic acid (2PBA) as internal standard was added into the urine and the target compound 3-PBA was extracted under acidic condition by using n-hexane as the extraction solvent. Then the target compound 3-PBA was extracted under alkaline condition The target compound is dissolved in the organic phase and the target compound is then taken to the aqueous phase. The target compound in the aqueous phase is extracted again with n-hexane under acidic conditions. After n-hexane is dried in nitrogen, the target compound is treated with N, (t-butyldimethylsilyl ) -N-methyl-trifluoroacetamide (MTBSTFA) to derivatize the target compound. The derivatized product was separated and detected by GC-MS to analyze the concentration of 3-PBA in urine. Results The linearity of 3-PBA in urine was linearly correlated with the concentration of 3-PBA in the range of 0.05-30 μg / L with a correlation coefficient of 0.9974. The minimum detectable limit of detection was 0.01 μg / L. The relative standard deviations (RSDs) were 2.4% -3.8% RSD was 8.7% ~ 10.8%; the relative recovery was 94.3% ~ 120.6%. Conclusion This method is more economical, more reliable and more sensitive than other similar methods. It can rapidly and accurately detect the concentration of 3-PBA, the main metabolite of pyrethroids in human urine, and predict the exposure level of this kind of pesticide in Chinese general population , And provided the basis for the safety evaluation of pyrethroid pesticides.