分散固相萃取-气相色谱串联质谱法检测大米中35种农药残留

Simultaneous determination of 35 kinds of pesticide residues in rice by dispersive solid phase extraction-gas chromatography-tandem mass spectrometry

目的建立分散固相萃取-气相色谱串联质谱法测定大米中35种农药残留的分析方法。方法采用QuEChERS方法对样品进行前处理。样品经乙腈提取,盐析后,提取液经N-丙基-乙二胺硅烷(N-propyl-ethylenediamine silane,PSA)和十八烷基硅胶(C18)分散固相材料净化后上机测定。用气相色谱-三重四极杆串联质谱仪进行多农残检测。结果35种农药在50~1000ng/mL之间呈良好的线性关系,相关系数r均大于0.99。在0.02、0.1、0.2 mg/kg加标水平下,35种农药的平均回收率为75.4%~128.6%,相对标准偏差(relative standard deviation,RSD)为0.6%~10.8%(n=6)。结论该方法快速、准确、灵敏,适合测定大米中多种农药残留。

Objective To establish the method for determination of 35 kinds of pesticide residues in rice by dispersive solid phase extraction-gas chromatography tandem mass spectrometry.Methods The samples were pretreated with QuEChERS method and extracted by acetonitrile.After salt extraction,the extracting solution was purified by PSA(N-propyl-ethylenediamine silane)and C18.The pesticide residues was determined by gas chromatography triple-quadrupole mass spectrometry.Results There was a good linear relationship between 50~1000 ng/m L and the correlation coefficient r was greater than 0.99.At 0.02,0.1,0.2 mg/kg,the average recoveries of 35 pesticides was 75.4%~128.6%,and the relative standard deviations(RSDs)were 0.6%~10.8%.Conclusion This method is rapid,accurate and sensitive for determination of pesticide residues in rice.