超高效液相色谱法快速测定罗汉果中乙螨唑的残留量

Rapid determination of etoxazole residues in Siraitia grosvenoriis by ultra high performance liquid chromatography

目的建立超高效液相色谱法检测罗汉果中乙螨唑残留的分析方法。方法样品经乙腈溶液提取,氯化钠盐析,加入无水硫酸镁脱水、并经过优化后的中性氧化铝和石墨化炭黑(GCB)填料组合进行净化,最后超高效液相色谱测定,基质标准溶液外标法定量。结果乙螨唑在0.05 mg/L~5.0 mg/L浓度内具有良好的线性关系,相关系数>0.999,方法的检出限为0.01 mg/kg,在0.05 mg/kg、1.0 mg/kg和2.0 mg/kg 3个添加水平下,乙螨唑在罗汉果的平均回收率为95.6%~102.9%,精密度为1.90%~2.74%。结论该方法样品前处理过程简单快速,分析时间短,符合农药残留试验的要求,适用于罗汉果中乙螨唑残留量的分析。

Objective To develop a reliable method for the determination of etoxazole residues in Siraitia grosvenoriis with sample preparation by ultra high performance liquid chromatography(UPLC).Methods The sample were extracted with acetonitrile,then salted out by sodium chloride,dehydrated by anhydrous magnesium sulfate and cleaned-up by optimized solid phase extraction materials of neutral alumina and graphitized carbon black(GCB),finally conducted for the detection of etoxazole residues by UPLC with external standard method considering sample matrix effects.Results The linearity was good in the concentration range of 0.05 mg/L-5.0 mg/L for etoxazole with the correlation coefficients more than 0.999.The limits of detection(LOD)for Siraitia grosvenoriis was 0.01 mg/kg.The average recoveries at three spiked concentration levels of0.05 mg/kg,1.0 mg/kg,2.0 mg/kg were in the 95.6%-102.9%,with the precision was within 1.90%-2.74%.Conclusion This method has advantages of rapid pretreatment and quick analysis which can meet the requirements of pesticide residues analysis,and is suitable for the determination of etoxazole in Siraitia grosvenoriis.