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

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50~1000 ng/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。

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

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/mL 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.