QuEChERS法与UPLC-MS/MS法测定水稻糙米中的吡唑醚菌酯残留

摘要

采用QuEChERS的前处理方法,建立了一种简单、快速、灵敏的水稻糙米中吡唑醚菌酯残留量的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。该方法以乙腈作为萃取溶剂,经液液分配萃取后,盐析分层,N-丙基-乙二胺键合硅胶(PSA)和C18键合硅胶净化后,进行超高效液相色谱-串联质谱(UPLC-MS/MS)分析,实现了样品的快速提取、净化、分离和检测。在优化条件下,吡唑醚菌酯在0.01~0.5 mg/L的范围内浓度与峰面积呈良好线性关系(R2=0.9900),回收率为82%~106%,相对标准偏差小于11%,该方法具有较好的准确度和精密度。经水稻田间试验,发现糙米中的吡唑醚菌酯残留量在0.006~0.023 mg/kg之间。%In this paper,a high efficient,rapid and sensitive determination method of pyraclostrobine in brown rice samples was proposed by a modified QuEChERS (quick,easy,cheap,effective,rugged and safe) method. Acetonitrile (ACN) was used to extract the residue of pyraclostrobine in samples.After salting out,the organic layer was cleaned up using PSA and C18 sorbents,and then the solution was directly analyzed by ultra-high -performance liquid chromatography -tandem mass spectrometry (UPLC-MS/MS),resulting in rapid extraction,clean-up,separation and detection of pyraclostrobine in samples. Under the optimized LC and MS conditions,good linearity in the range of 0.01~0.05 mg/kg was obtained for pyraclostrobine with R2 of 0.990 0.The method recoveries of the pyraclostrobine spiked at low,middle and high concentrations in blank rice samples were from 82% to 106%,with relative standard deviations less than 11%,indicating that the proposed method has good accuracy and precision.At last,the proposed method was applied to analyze the final residues of pyraclostrobine in samples,and the residues of pyraclostrobine in brown rice samples were in the range of 0.006~0.023 mg/kg.