基于乙醇体系的一测多评液相色谱法测定饮用水中4种农药残留

Determination of Four Pesticide Residues in Drinking Water by LC with Quantitative Analysis of Multi-Components by Single Marker Method Based on Ethanol System

目的:建立一种基于乙醇体系的液相色谱一测多评法测定饮用水中4种农药残留。方法:分别考察不同固相萃取柱、不同洗脱溶剂、水样pH值、校正因子等因素对分析效果的影响,最终确定水样经PEP(Polar enhanced polymer)固相萃取柱富集净化后,以乙醇和20 mmol/L乙酸铵为流动相,经C18-AR液相柱分离,DAD(Diode array detector)检测器检测。同时,以三甲苯草酮为参考,建立一测多评法测定4种农药残留的计算模型。通过改变流速、柱温、进样量和仪器等因素考察校正因子f的稳定性。结果:该方法回收率为92.6%~102.4%,精密度为0.6%~5.4%,检出限为1.4~2.3μg/L。校正因子稳定性良好,f苯/三=0.685、f氟/三=1.403、f草/三=1.276。结论:该方法处理过程简单、易于操作、环境兼容性好。一测多评法与外标法在定量结果上无显著差异,适合用于开展饮用水中4种农药残留的检测。

Object:To establish a method for determination of 4 kinds of pesticide residues in drinking water by liquid chromatography(LC)with quantitative analysis of multi-components by single marker method based on ethanol system.Methods:The effects of different solid phase extraction columns,elution solvents,water sample pH,and correction factors on the analysis were investigated,and the water samples were finally determined to be concentrated and purified by polar enhanced polymer(PEP)solid phase extraction column,separated by C18-AR liquid chromatograthy column with ethanol and 20 mmol/L ammonium acetate mobile phase and detected by diode array detector(DAD).At the same time,a calculation model for the determination of 4 kinds of pesticide residues with quantitative analysis of multi-components by single marker method was established with reference to tralkoxydim,and the stability of relative correction factor f was investigated by changing the flow rate,column temperature,sample size and instrument.Results:The method showed good recovery rates ranging from 92.6%to 102.4%and precision ranging from 0.6%to 5.4%,with detection limits ranging from 1.4μg/L to 2.3μg/L.The correction factors were stable,with values of f metrafenone/tralkoxydim=0.685,f fluoronitrofen/tralkoxydim=1.403,and f chlornitrofen/tralkoxydim=1.276.Conclusion:This method offers advantages such as simplicity in processing,ease of operation,and environmental compatibility.The quantitative analysis of multi-components by single marker method showed no significant difference in quantitative results compared to the external standard method,making it suitable for the detection of four pesticide residues in drinking water.