水体中有机磷农药分析基质效应影响及其补偿方式研究

Study on the Matrix Effects of Organophosphorus Pesticides Analysis in Water and Its Compensation Methods

采用固相萃取富集、气相色谱分离、氮磷检测器测定水体中有机磷农药敌敌畏、甲胺磷、乙酰甲胺磷、甲拌磷、氧乐果、久效磷和乐果,对测定过程中的基质效应进行研究。结果表明,水体中有机磷农药测定的过程中存在基质效应,其基质增强比例为1.006~3.147。基质效应与色谱分析条件、有机磷农药种类等有关。通过添加分析保护剂可有效降低基质效应对测定结果的影响,在对L-古洛糖酸γ内脂、聚乙二醇200和聚乙二醇400等的研究中,发现添加PEG200的效果最优。分析保护剂的加入不仅提高了测定的灵敏度,而且可以提高测定结果的精密度和准确度,用于实际样品分析可获得较高的回收率,满足分析检测要求。

An analytical method coupling solid phase extraction and GC-nitrogen and phosphorus detectors was applied to the determination of dichlorvos,methamidophos,acephate,phorate,omethoate,monocrotophos,and dimethoate in water.Matrix effect of organophosphorus determination was also conducted.The results showed that there was a matrix effect in the determination of organophosphorus pesticides in water,and the response enhancement ratios ranged from1.006to3.147.The response enhancement effects were different for chromatographic analysis conditions,organophosphorus pesticide types and so on.Matrix effects can be reduced by the use of analyte protectants.It was found that the effect of adding polyethylene glycol200(PEG200)is the best among the L gulonic acid gamma lactone,PEG200and PEG400.The addition of the analyte protectants not only improved the sensitivity of the measurement,but also enhanced the precision and accuracy of the determination results.It can get a higher recovery rate for the samples analysis to meet the analysis requirements.