微波辅助-固相萃取-高效液相色谱法测定稻谷中苯噻草胺残留量

High performance liquid chromatography combined with microwave-assisted extraction and solid phase extraction in determination of mefenacet residues in rice

目的:建立测定稻谷中苯噻草胺残留量的微波辅助-固相萃取-高效液相色谱法(MAE-SPE-HPLC)。方法:以丙酮-乙腈(体积比3:7)为提取剂,采用微波辅助萃取稻谷中残留的苯噻草胺,经弗罗里硅土固相萃取小柱净化后,用高效液相色谱-二极管阵列检测器检测。以乙腈-水为流动相,流速1.0ml/min,217nm检测。结果:苯噻草胺在0.198～9.900μg/ml范围内呈良好的线性关系,最低检测限为0.0396μg/ml。稻壳添加平均回收率为90.8%,RSD为1.8%;糙米添加平均回收率为85.6%,RSD为2.5%。结论:MAE-SPE-HPLC法简便、快速,可用于稻谷中苯噻草胺残留量的测定。

Objective： To establish a method by combining microwave-assisted extraction（MAE）, solid phase extraction （SPE） and high performance liquid chromatography （HPLC） for determination of the mefenacet residues in rice. Methods： Acetone and acetontrile （3 ： 7） were used as extraction solvent. Microwave-assisted extraction was used to extract mefenacet residues in the rice. The extracts were then cleaned up with a Florisil cartridge and then subjected to Hypersil C18 column（5 μm,4. 6 mm× 200 mm ）, with acetonitrile ： water（50 ： 50,V/V）solution as mobile phase and with a flow rate of 1.0 ml/min; the ultraviolet detection wavelength was at 217 nm. Results： Good linear correlation for mefenacet was found within a concentration range of 0. 198-9. 900 μg/ml. The detection limit was 0. 039 6 μg/mL for mefenacet（S/N=2）. The average recovery rate of rice hull and brown rice were 90.8% （RSD 1.8% ） and 85.6%（RSD 2.5%） ,respectively. Conclusion： The present method is simple and rapid; it can be used for the determination of mefenacet residues in rice.