凝胶渗透色谱-气相色谱串联质谱法测定动物脂肪中164种农药残留

建立了气相色谱-串联质谱法(GC-MS-MS)同时测定动物脂肪中164种农药的多残留分析方法。样品经乙腈均质提取2次,合并提取液并在45℃水浴中旋转浓缩至1 mL,加入5 mLV(环己烷)∶V(乙酸乙酯)=1∶1进行溶剂交换2次后,用V(环己烷)∶V(乙酸乙酯)=1∶1稀释至10 mL,用凝胶渗透色谱(GPC)净化,GC-MS-MS多反应监测模式(MRM)测定,内标法定量。本方法研究的164种农药的线性相关系数为0.9438~1.0000,其中有154种在0.9900以上,占总数的93.9%。方法检出限(S/N≥3)为0.1~360.0μg/kg,其中在10.0μg/kg以下的有121种,占研究农药总数的73.8%。用猪、鸡、牛、羊4种不同的脂肪在低、中、高3个添加水平评价了164种农药的方法效率,其中有150种的回收率在70%~120%之间,相对标准偏差(RSDs)在20%以内。本方法适用于不同动物脂肪中150种农药多残留的定量测定和14种农药的定性测定。

Determination of 164 pesticide residues in animal fat by gel permeation chromatography-gas chromatography-tandem mass spectrometry

A gas chromatography-tandem mass spectrometric (GC-MS-MS) method has been developed for simultaneous determination of 164 pesticide residues in animal fat. The target analytes were extracted with 35 mL of acetonitrile for twice and concentrated to 1 mL in 45 ℃ water bath with a rotary evaporator. The internal standard was added to the concentrated extracts, which was then filtered by 0.45 μm millipore filters. Then the solution was transferred to a 10 mL volumetric flask with cyclohexane+ethyl acetate (1+1) and purified on line by gel permeation chromatography (GPC). The sample solution was determined by GC-MS-MS in multiple reaction monitoring mode (MRM). The established method showed satisfactory linearity with correlation coefficients of 0.9438～1.0000, among which 93.9% were above 0.9900. Under optimized conditions, the detection limits (LOD) (S/N≥3) were in the range of 0.1～360.0 μg/kg, among which 73.8% were below 10.0 μg/kg. Among 164 targeted pesticides, 150 pesticides could be determined quantitatively, the average spiked recoveries of which were between 70% and 120% and the relative standard deviations (RSDs) of which were below 20%, indicating that the method is selective, accurate and suitable for simultaneous quantitation of 150 pesticide residues in animal fat.