提出了同时测定蔬菜、水果中9种农药残留的高效液相色谱分析方法.样品经乙腈超声提取及Florisil固相萃取柱富集,用正己烷-二氯甲烷(40+60)混合溶剂从柱上洗脱农药残留使净化.洗脱液在40 ℃氮气吹干,残渣用1.0 mL甲醇溶解,取1 μL样品溶液注入高效液相色谱仪测定.采用C18色谱柱分离,以甲醇-水混合溶液为流动相,紫外254 nm检测.结果表明:9种农药的质量浓度在0.01~1.0 mg·L-1范围内呈线性关系,方法的检出限(3S/N)在0.009~0.049 mg·kg-1之间.分别以蔬菜和水果为基体,加入标准溶液进行回收试验,测得蔬菜中9种农药的回收率为68.3%~103.2%,相对标准偏差(n=6)为1.8%~13.9%;水果中农药的回收率为69.4%~106.0%,相对标准偏差(n=6)为2.9%~11.8%.

A method of HPLC for simultaneous determination of 9 kinds of pesticides in fruit and vegetable samples was proposed.The samples were extracted with acetonitrile,and residual pesticides in sample solution were separated and enriched by solid phase extraction (SPE) on Florisil column.The SPE column was eluted with a mixture of n-hexane and dichloromethane (40+60),and the eluate obtained was evaporated to dryness by N2-blowing at 40 ℃ and taken up with 1.0 mL of CH3OH.A aliquot of 1.0 μL was used for HPLC determination.C18 column was used as the stationary phase and a mixture of methanol and water was used as the mobile phase.UV detection at 254 nm was adopted.Linear relationships were found in the same range of 0.01-1.0 mg·L-1 for the 9 pesticides,with values of detection limit (3S/N) in the range of 0.009-0.049 mg·kg-1.On the base of samples of fruit and vegetable,test for recovery were made by standard adiition method.Values of recovery and RSD′s (n=6) found were in the ranges of 68.3%-103.2% and 1.8%-13.9% (for vegetables);69.4%-106.0% and 2.9%-11.8% (for fruits),respectively.