气相色谱-质谱法测定蔬菜和水果中193种农药的残留量

在系统优化固相萃取吸附剂填料类型、洗脱溶剂种类及体积的基础上,建立了蔬菜和水果中193种农药残留的气相色谱-质谱(GC-MS)检测方法。样品经乙腈均质提取,C₁₈/PSA固相萃取柱净化,乙腈洗脱,GC-MS选择离子监测(SIM)模式检测,以磷酸三苯酯内标法定量。结果表明,130种农药在10~1000 μg/L、34种农药在20~1000 μg/L、26种农药在50~1000 μg/L、3种农药在100~1000 μg/L范围内线性关系良好,相关系数为0.9967~1.0000,方法检出限(以信噪比为3计)为0.04~8.26 μg/kg,添加回收率为71.6%~117.9%,相对标准偏差为3.0%~11.8%。该方法样品处理简单快速,相比其他多残留分析方法净化效果好,其灵敏度和选择性明显提高,适用于日常检测工作。

Determination of 193 pesticide residues in vegetables and fruits by gas chromatography-mass spectrometry

On the basis of optimization of solid phase extraction adsorbent, eluting solvent types and amounts, a gas chromatography-mass spectrometric method was developed for the determination of 193 pesticide residues in vegetables and fruits. The analytes were extracted from the samples using acetonitrile. The extract was cleaned-up with a C₁₈/PSA solid-phase extractor, eluted by acetonitrile and analyzed by GC-MS under selected ion monitoring (SIM) mode using triphenyl phosphate (TPP) as internal standard. The linear range was from 10 to 1000 μg/L for 130 pesticides, from 20 to 1000 μg/L for 34 pesticides, from 50 to 1000 μg/L for 26 pesticides, from 100 to 1000 μg/L for the other 3 pesticides with the good correlation coefficients (r≥0.9967). The limits of detection were 0.04-8.26 μg/kg. The mean recoveries of the pesticides were 71.6%-117.9%. The relative standard deviations were 3.0%-11.8%. This method is simple, rapid, sensitive and specific. It is appropriate for the simultaneous identification and quantification of the multi-residues in fruits and vegetables.