固相萃取-毛细管液相色谱测定食品和水样中有机磷和氨基甲酸酯类杀虫剂残留

摘要

采用乙腈提取、固相萃取(SPE)富集浓缩技术结合自行研制开发的毛细管液相色谱(CLC)仪,同时分离测定了食品和水样中1种有机磷和3种氨基甲酸酯类杀虫剂残留.对影响 SPE效率和 CLC分离检测的各类因素进行了优化,包括固相萃取柱种类、样品 pH、洗脱剂种类和体积、上样速率、盐效应、上样体积、检测波长、流动相种类和比例等.结果表明,4种杀虫剂在6 min内达到完全分离,检出限为0.35~1.20 μg/kg,定量限为1.17~4.00 μg/kg.使用该 SPE-CLC法对西红柿、黄瓜、苹果样品和自来水、湖水水样进行加标回收测定,得到食品中加标回收率为72.41%~107.15%,相对标准偏差≤8.12%;水样中加标回收率为71.45%~109.25%,相对标准偏差≤9.28%.该法能够满足农药多残留分析要求.%A method was established for the simultaneous separation and determination of one organophosphorus and three carbamate insecticide residues in food and water samples by solid phase extraction(SPE)followed by analysis using a home-made capillary liquid chromatogram. Various parameters possibly affecting the efficiencies of capillary liquid chromatography(CLC) and SPE were investigated in detail,such as type of SPE column,pH value of samples,type and volume of elution solvent,flow rate of loading sample,salt effect,loading volume,detec-tion wavelength,and type and ratio of mobile phases. Under the optimized experimental condi-tions,the four insecticides were separated completely within 6 min. The limits of detection and limits of quantification were 0.35-1.20 μg/kg and 1.17-4.00 μg/kg,respectively. Satisfactory recoveries of the SPE-CLC method were achieved for spiked food samples of tomato,cucumber and apple ranging from 72.41% to 107.15% with the relative standard deviations(RSDs)no more than 8.12%,and for spiked tap/lake water samples ranging from 71.45% to 109.25% with the RSDs no more than 9.28%. The method can meet the requirements for multi-residue analysis of insecticides.