凝胶渗透色谱净化/液相色谱-串联质谱法对动物脂肪中111种农药残留量的同时测定

建立了液相色谱-串联质谱法同时测定动物脂肪中111种农药残留的分析方法.样品经乙腈均质提取2次,旋转蒸发浓缩后经过凝胶渗透色谱净化.111种农药在Atlantis T3柱上以乙腈和0.1%甲酸溶液为流动相,梯度洗脱条件下完成分离,采用电喷雾电离串联质谱在正离子多反应监测模式下进行测定.目标化合物的保留时间为2.4 ～33.8 min,线性相关系数为0.984 5 ～0.999 9;在4种动物脂肪中分别添加1倍、2倍、4倍定量下限3个水平的平均回收率为60% ～120%,相对标准偏差为0.6% ～19.8%;111种农药在动物脂肪中的检出限为0.20 ～960 μg/kg,定量下限为0.40 ～2 400 μg/kg.该方法操作简单、灵敏度高、选择性好,符合农药多残留分析的要求.

Determination of 111 Pesticides Residues in Animal Fat by Gel Permeation Chro-matography Purification/Liquid Chromatography-Tandem Mass Spectrometry

A new analytical method was established for the simultaneous determination of 111 pesticide residues in animal fat by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The sample was extracted with acetonitrile using a high speed homogenizer and cleaned up on a gel permeation chromatography(GPC) using ethyl acetate-cyclohexane(1 ∶ 1,by volume) as mobile phase.The 24-48 min elute fraction was collected for subsequent analysis.The target compounds were separated on a Atlantis T3 column by gradient elution with acetonitrile and 0.1% formic acid solution(by volume) as mobile phase and 111 pesticide residues were quantified in positive multiple reaction monitoring mode(MRM).The retention time of the pesticide residues were between 2.4-33.8 min,and the linear correlation coefficients were in the range of 0.984 5-0.999 9.The limit of detection(LOD) for 111 pesticides in animal fat were between 0.20 μg/kg and 960 μg/kg,and the LOQ were between 0.40 μg/kg and 2 400 μg/kg.At the spiked level of limit of quantification(LOQ),2 times of LOQ and 4 times of LOQ in four animal fat,such as pork,chicken,beef,mutton,the recoveries of the pesticide residues were between 60% and 120% and the relative standard deviations were in the range of 0.6% -19.8%.The established method is simple,sensitive and selective,and could meet the requirement of pesticide multi-residues analysis.