固相萃取-双柱双检测器-气相色谱法同时测定蔬菜中多种类农药残留

Simultaneous determination of multiple pesticides residues in vegetables by solid phase extraction-double columns and double detectors-gas chromatography

目的建立蔬菜中三大类农药的固相萃取-双柱双检测器-同一升温程序下气相色谱同时测定法。方法样品经乙腈溶剂匀浆提取,Carb-NH2柱净化,样品间隔60 s进样2次,先经CP-Sil 5CB柱分离后进入NPD检测器进行有机磷和氨基甲酸酯类农药测定,然后经CP-Sil 24CB柱分离后进入ECD检测器进行有机氯和拟除虫菊酯测定,阳性样品双柱检测器端互换双柱验证。结果三大类农药在0.01μg/ml^2.0μg/ml范围内质量浓度与峰面积有良好的线性关系,方法检测限在0.0001 mg/kg^0.010 mg/kg,加标回收率在76%~124%之间,相对标准偏差(RSD)在0.95%~4.7%。结论该方法简便、快速,结果准确,能满足蔬菜中多种类农药残留同时分析的要求。

Objective To establish a method for simultaneous detection of three categories of pesticide residues in vegetables by SPE - dual column - dual detector - gas chromatography under the same temperature program. Methods The samples were extracted by aeetonitrile, purified with Carl） - NH2 SPE column and injected twice with interval of 60 s for determination of or- ganophosphorus and carbamate pesticides by CP - Sil 5CB - NPD, organoehlorine and pyrethroid by CP - Sil 24CB - ECD re- spectively. The positive samples were determined again by interchangeable column. Results The three large categories of pes- ticides showed good lincarity in the range of 0.01μg/ml -2.0 μg/ml, the detection limit was 0.0001 mg/kg --0. 010 mg/kg, the recovery rate ranged from 76% to 124% , and the relative standard deviation varied between 0.95% and 4.7%. Conclu- sion This method is simple, rapid and accurate, it can meet the analysis requirements of many kinds of pesticide residues in vegetables.