气质联机分析蔬菜中农药多残留及基质效应的补偿

摘要建立了蔬菜中52种农药化合物的气相色谱\|质谱检测方法, 考察了基质效应和分析保护剂在方法中的应用, 评价了3种分析保护剂组合的加入对补偿基质效应的影响, 确定了最佳配比. 样品前处理采用乙腈提取, 用PSA(Primary-secondary amine)固相材料分散净化技术, 用气质联机在选择离子监测模式下分析检测. 该方法在0.01～1.00 mg/L范围内线性关系良好, 相关系数大于0.98, 最低检测浓度除溴氰菊酯和异菌脲外均在0.2～9.4 mg/kg之间, 各化合物添加回收率为81.8%～119.5%, 相对标准偏差为0.8%～17.6%.

Rapid Determination of Pesticide Multiresidues in Vegetable by Gas Chromatography-mass Spectrometry and Compensation for Matrix Effect with Protectants

Abstract A multi-residue method is described for rapid determination of 52 multi-class pesticides, including  their isomers, in vegetables by gas chromatography-mass spectrometry(GC-MS) with the aid of analyte protectants. Addition of different  combinations of  protectants before injection for compensation of matrix effect was demonstrated. Pesticides were extracted from samples with acetonitrile and the extract was cleaned up by using dispersive method by primary-secondary amine sorbent. Pesticides was injected into GC with the aid of analyte protectants 3-ethoxy-1,2-propanediol(20 mg/mL)and D-sorbitol(1 mg/mL)] , followed by MS detection under EI ionization and selective ion monitoring mode. Good linear and lower limits of detection were obtained, the linear range are between 0.01 and 1.00 mg/L, correlation coefficients are better than 0.98, and the detection limits are mainly between 0.2 and 9.4 μg/kg. All compounds have mean recoveries of 81.8%-119.5% and the relative standard deviation is between 0.8% and 17.6%.