摘要
乐果、敌敌畏、甲拌磷、甲基对硫磷等极性有机磷农药与水具有相似极性,而且在地下水中含量相对偏低,采用常规二氯甲烷作萃取溶剂,液-液萃取时提取比较困难,存在检测组分萃取回收率低、方法稳定性差,方法检出限高等问题。通过加入丙酮作为辅助萃取溶剂,显著提高了检测回收率和方法稳定性。该方法以丙酮-二氯甲烷(体积比1∶9)为萃取剂,液-液萃取、气相色谱-火焰光度检测器检测地下水中敌敌畏、甲拌磷、乐果、甲基对硫磷、马拉硫磷、毒死蜱、对硫磷7种极性有机磷农药。优化条件下,水样平均加标回收率为88.1%~109%,相对标准偏差为0.28%~4.27%(n=3),方法检出下限为ρ=1.17~4.22 ng/L(水样1L)。改进后的分析方法显著改善了准确度、精密度等有效性参数,有利于更准确地测定地下水中极性有机磷农药。
Polar organophosphorus pesticides,such as dimethoate,dichlorvos,phorate and methyl parathion,have similar polarity with water. Meanwhile,their content in groundwater is relatively low. However,it is difficult to extract polar organophosphorus pesticides from water when using methylene chloride as solvent,which has low extractive recoveries,poor stability and high detection limit. Through the addition of acetone as an auxiliary extractive solvent, the recoveries and stability were significantly improved. In this method, acetonedichloromethane( 1∶ 9,v: v) was used as the extracting solvent,which detected dichlorvos,phorate,dimethoate,methyl parathion, chlorpyrifos and parathion in the groundwater through liquid-liquid extraction and gas chromatography-flame photometric detector. Under the optimized conditions,the average recovery rate of water samples was in the range of 88. 1% ~ 109%,with RSDs( n = 3) between 0. 28% and 4. 27%. The detection limit was 1. 17 ~ 4. 22 ng / L. The modified analysis method significantly improved the validity parameter,such as accuracy and precision,which is beneficial for more accurate analysis of polar organophosphorus pesticides in groundwater.
出处
《水资源保护》
CAS
CSCD
2015年第4期98-102 115,共6页
Water Resources Protection
基金
国土资源部地质大调查项目(1212011220324)
中国地质调查项目(1212010816028
1212011120283)
关键词
丙酮
液-液萃取
气相色谱-火焰光度检测器
地下水
有机磷
农药残留
acetone
liquid-liquid extraction
gas chromatography-flame photometric detector
groundwater
organophosphates
pesticide residues
