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目的建立固相萃取-气相色谱-串联质谱法同时测定大米中10种除草剂残留的方法。方法采用乙腈漩涡提取样品中待测组分,通过比较Carbon/NH2柱、Florisil柱、HLB柱、PSA柱4种小柱对大米中10种除草剂的吸附和净化情况,选Carbon/NH2柱进行净化,大米对10种除草剂均存在基质加强效应,以大米基质校准工作曲线,采用气相色谱-串联质谱法在多反应监测(MRM)模式下进行测定,外标法定量。结果 10种除草剂的质量浓度为40μg/L~1 600μg/L时,线性关系良好,相对标准偏差(RSD)<10%,加标回收率为76.9%~109.5%。按信噪比(S/N)为10计,本方法的检出限(LOQ)为0.09μg/kg~1.2μg/kg。结论该分析方法背景干扰低、灵敏度高、检出限低于国家标准及相关文献报道值,适合大米中除草剂的同时测定。
Objective To establish a method for the simultaneous determination of ten herbicide residues in rice by solid-phase extraction-gas chromatography-tandem mass spectrometry. Methods Acetonitrile swirl was used to extract the components to be tested. The adsorption and purification of 10 herbicides in rice were compared by using Carbon / NH2 column, Florisil column, HLB column and PSA column. Carbon / NH2 column Purification, rice matrix enhancement effect on the existence of 10 kinds of herbicides, the rice matrix calibration curve, the use of gas chromatography-tandem mass spectrometry in multiple reaction monitoring (MRM) mode of measurement, external standard. Results The results showed that the linearity was good with the relative standard deviations (RSDs) <10% and the spike recoveries were 76.9% -109.5% when the concentration of 10 herbicides was 40μg / L ~ 1 600μg / L. The detection limit (LOQ) was 0.09μg / kg ~ 1.2μg / kg according to the S / N ratio of 10. Conclusion The method has low background interference and high sensitivity, and the detection limit is lower than the national standards and reported values in the literature, which is suitable for the simultaneous determination of herbicides in rice.