加压毛细管电色谱法分析果蔬汁饮品中8种农药残留

该实验建立一种可以同时测定果蔬汁饮品中乐果、敌敌畏、克百威、甲萘威、莠去津、甲基对硫磷、马拉硫磷、百菌清的加压毛细管电色谱（pCEC）法。样品加入1.0%氨水的乙腈溶液提取并以石墨化炭黑（GCB）固相萃取柱净化,检测的流动相为乙腈:5 mmol/L Tris-HCl（66∶34,V/V）体系（pH 7.0）,施加-9 kV电压进行分离,二极管阵列检测器（DAD）的检测波长为220 nm,并以外标法定量。结果表明,8种农药组分在一定质量浓度范围内线性关系良好,检出限（LOD）为0.03～3.70 μg/mL,定量限（LOQ）为0.1～11.2 μg/mL,加标回收率为84.4%～107.0%,精密度实验结果的相对标准偏差（RSD）为2.0%～6.3%。该方法具有操作简单、专属性强、灵敏度高等优点,可满足果蔬汁饮品中多种农药组分的检测要求。

Analysis of 8 pesticide residues in fruit and vegetable drinks by pressurized capillary electrochromatography

A pressurized capillary electrochromatography (pCEC) method was developed for the simultaneous determination of dimethoate, dichlorvos, carbofuran, carbaryl, atrazine, methyl parathion, malathion and chlorothalonil in fruit and vegetable drinks. The sample was extracted with acetonitrile solution of 1.0% ammonia water and purified with graphitized carbon black (GCB) solid phase extraction column. The sample was separated using acetonitrile: 5 mmol/L Tris-HCl (66∶34, V/V) (pH 7.0) as mobile phase with -9 kV applied voltage. The detection wavelength of diode array detector (DAD) was 220 nm, and the external standard method was used for quantification. The results showed that the linearity of the 8 pesticide components was good in a certain mass concentration range, the limit of detection (LOD) was 0.03-3.70 μg/ml, the limit of quantitation (LOQ) was 0.1-11.2 μg/ml, and the recovery rate of standard addition was 84.4%-107.0%, and the relative standard deviation (RSD) of precision tests results was 2.0%-6.3%. The method had the advantages of simple operation, strong specificity and high sensitivity, which could meet the detection requirements of various pesticide components in fruit and vegetable drinks.