气相色谱-质谱法测定番茄酱中甲霜灵、苯霜灵、恶霜灵的残留量

Determination of metalaxyl,benalaxyl and oxadixyl residues in tomato sauce by gas chromatography mass spectrometry

目的：建立了番茄酱中甲霜灵、苯霜灵、恶霜灵残留量的气相色谱-质谱（GC—MS）测定方法。方法：番茄酱经乙腈提取盐析，样液浓缩后丙酮溶解定容。净化液用GC—MS测定，外标法定量。结果：4个添加水平的平均回收率在76．5％～103．2％之间，相对标准偏差在2．1％～7．8％之间。3种农药的最低检出限（LOD）分别为：甲霜灵、苯霜灵0．01mg／kg；恶霜灵0．05mg／kg。结论：该法简便、快速、灵敏、准确，各项技术指标均满足农药残留检测的要求。

Objective：A method for determination of metalaxyl, benalaxyl and oxadixyl residues in tomato sauce by capillary gas chromatography - mass spectrometry （ GC - MS） has been developed. Methods. Extraction of the tomato sauce sample with acetonitrile was followed by salting - out and concentration step, finally the extract was dissolved in acetone. External standards were used for quantitative determination. Results：The average recoveries and relative standard deviations ranged from 76. 5% to 103. 2% and 2. 1% to 7. 8% ,respectively. The limit of detection （LOD） was 0. 01 mg/kg for metalaxyl and benalaxyl,and 0. 05 mg/kg for oxadixyl. Conclusion：The method is simple, rapid, sensitive and accurate and it is suitable for routine inspection of residues of three pesticides in tomato sauce.