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目的建立采用分散固相萃取-液相色谱-串联质谱法同时测定果蔬中21种氨基甲酸酯类农药多残留的分析方法。方法称取5g样品,用15 ml含有1%乙酸的乙腈振荡提取后,每3 ml提取液加入900 mg无水硫酸镁、150 mg PSA,再根据提取液色素含量,决定是否加入GCB,分散固相萃取法净化,经涡旋、离心、过滤后,采用LC-MS/MS,在正离子模式下选用多反应监测(MRM)扫描测定。结果 21种氨基甲酸酯类农药在0.5 ng/ml~20ng/ml时线性相关系数均在0.99以上。分别对菜心、黄瓜、葡萄、香蕉进行3个水平的加标回收试验(10μg/kg、20μg/kg、50μg/kg),21种目标物的回收率为71.6%~119.8%,相对标准偏差为2.4%~23.0%。结论该方法前处理过程简单快速、灵敏度高、准确度好,可以满足果蔬中多种氨基甲酸酯类农药残留同时检测的要求。
OBJECTIVE To establish a method for simultaneous determination of 21 residues of carbamate pesticides in fruits and vegetables by dispersive solid-phase extraction-liquid chromatography-tandem mass spectrometry. Methods Weigh 5g sample, extract with 15ml acetonitrile containing 1% acetic acid, add 900mg anhydrous magnesium sulfate and 150mg PSA to 3ml extract, and decide whether to add GCB according to the pigment content of the extract. Phase extraction and purification. After being vortexed, centrifuged and filtered, LC-MS / MS was used to select multiple reaction monitoring (MRM) scans in positive ion mode. Results The linear correlation coefficients of 21 carbamate pesticides at 0. 5 ng / ml ~ 20 ng / ml were above 0.99. Three levels of spiked recoveries (10μg / kg, 20μg / kg, 50μg / kg) were collected from Brassica campestris, Cucumber, Grape and Banana respectively. The recoveries of 21 target species ranged from 71.6% to 119.8%. The relative standard deviations 2.4% ~ 23.0%. Conclusion The pretreatment method of this method is simple, rapid, sensitive and accurate, which can meet the requirements of simultaneous detection of various carbamate pesticide residues in fruits and vegetables.