固相微萃取—高效液相色谱联用测定番茄中氨基甲酸酯类农药残留

Determination of Carbamates Residues in Tomatoes by Solid Phase Microextraction Coupled with High Performance Liquid Chromatography

目的:采用固相微萃取(SPME)-高效液相色谱法(HPLC)建立番茄中氨基甲酸酯类农药残留的分析方法。方法:通过试验优化,在室温、搅拌速度为1100r/min条件下,选用65μm聚二甲基硅氧烷/二乙烯基苯(PDMS/DVB)涂层萃取纤维萃取40min,然后在流动相中静态解吸2min,之后进行HPLC分析。HPLC的色谱柱为SymmetryRC18反相色谱柱,乙腈-水V(乙腈)∶V(水)=40∶60为流动相,流速1.0mL/min。呋喃丹、西维因、异丙威的检测波长分别为278、220、205nm。结果:3种农药在0.1～2mg/kg范围内呈良好的线性关系,线性相关系数分别为0.9935、0.9980和0.9943。检出限(信噪比为3)0.011～0.023mg/kg,回收率91.2%～94.6%,相对平均偏差(RSD)1.9%～4.4%。结论:该方法适用于番茄中氨基甲酸酯类农药的残留分析。

Objective： Aim A novel analytical method for the determination of carbofuran, carbaryl and isopmcarb in tomatoes has been developed, which was based on solid-phase microextraction （SPME） coupled with high performance liquid chromatography （HPLC）. Method： The tomatoes were first blended and centrifuged. Then, an aliquot of the resulting extracting solution was subjected to SPME on a 65 p,m polydimethylsiloxane/divinylbenzene （PDMS/DVB） fiber for 40 min at room temperature with the solution being stirred at 1 100 r/rain. The extracted pesticides on the SPME fibre were desorbed in mobile phase into SPME/HPLC interface for HPLC analysis. Separations were carried out on a Symmetry C18 Column. Mobile phase was acetonitrile/water mixture （40/60,V/V）; flow rate was 1.0 mL/min; detection wavelengths for quantification were 278, 220 and 205 nm for carbofuran, carbaryl and isoprocarb, respectively. Results：The method was linear over the range from 0.1 to 2 mg/kg in tomatoes for all the three compounds with the detection limits of 0.015, 0.023 and 0.011 mg/kg and the correlation coefficients of 0.9935, 0.9943 and 0.9980, respectively. The average recover- ies were in the range from 91.2% to 94.6% with the relative standard deviations（RSD） from 1.9 % to 4.4 % at 0.2 mg/ kg level. Conclusion： The method is simple, sensitive and organic solvent-free, and is suitable for the determination of residues of carbofuran, carbaryl and isoprocarb in tomatoes.