河水及淤泥中农药残留的液质联用检测及江苏稻田区污染现状

采集江苏稻田种植区872份河水和近河淤泥样品,分析稻田常用农药对河水污染现状,建立丙溴磷、三唑磷、丙环唑和咪鲜胺液质联用检测方法。河水样品经饱和氯化钠溶液和二氯甲烷+丙酮混合溶液萃取,淤泥样品经无水硫酸钠和氯化钠及丙酮+正己烷混合溶液提取,C18反相色谱柱分离,三重串联四极杆质谱仪检测。结果表明:建立的液相色谱质谱联用仪检测方法对丙溴磷、三唑磷和丙环唑在河水和淤泥中的检测限均为0.001 5mg.kg-1,定量限均为0.005mg.kg-1。咪鲜胺在河水和淤泥中的检测限均为0.003mg.kg-1,定量限均为0.010mg.kg-1。各农药在0.01～1.0μg.mL-1范围内与响应值线性相关,决定系数均在0.99以上。对丙溴磷、三唑磷和丙环唑在河水和淤泥中分别添加0.005、0.05和0.5mg.kg-1 3个水平,对咪鲜胺在河水和淤泥中分别添加0.01、0.1和1.0mg.kg-1 3个水平,结果表明,平均回收率为80%～110%,相对标准偏差均在20%以内。对江苏稻田种植区河水及淤泥样品进行分析,河水中丙溴磷、三唑磷和咪鲜胺检出率分别为3.7%、1.7%和2.5%,淤泥中三唑磷检出率为1.4%,表明河水污染程度高于淤泥。试验建立的方法简便、快速,且灵敏度、准确度高、精密度好,符合农药残留检测规范要求,适用于高通量农药残留检测。

Determination of pesticide residues in river water and river sediment by LC-MS/MS and survey of contamination status in rice cultivation areas in Jiangsu province

In order to survey the contamination status of rivers by common pesticides used in rice,we analyzed 872 water and soil samples from rivers in rice cultivation areas in Jiangsu province.The water samples were extracted by sodium chloride solution and the mixture of methylene dichloride+acetone;the soil samples by anhydrous sodium sulfate,sodium chloride and the mixture of acetone+n-hexane.The extractions were dried by the stream of nitrogen,separated by the reverse phase column C18,and then detected by liquid chromatography tandem mass spectrometry(LC-MS/MS).The results showed that the limits of detection(LODs) of triazophos,propiconazole and profenofos in water and soil were all 0.001 5 mg·kg-1 and limits of quantitation(LOQs) were all 0.005 mg·kg-1.The LODs of prochloraz in water and soil were both 0.003 mg·kg-1,and LOQs were both 0.010 mg·kg-1.The response of each pesticide showed nice linearity with the concentration within the range of 0.01-1.0 μg·mL-1(R2>0.99).When triazophos,propiconazole and profenofos were spiked into water and soil samples at the levels of 0.005,0.05 and 0.5 mg·kg-1 and prochloraz at the levels of 0.01,0.1 and 1.0 mg·kg-1 respectively,the results demonstrated that the recoveries ranged between 80% and 110% and the relative standard deviations(RSDs) were less than 20%.When water and soil samples from river in rice cultivation areas in Jiangsu were analyzed,the detection rates of triazophos,propiconazole and prochloraz were 3.7%,1.7% and 2.5%,respectively in the water samples;the detection rate of triazophos in the soil was 1.4%.Compared with the soil samples,the water were contaminated more seriously.The method established in this paper was simple,rapid,sensitive,accurate and precise,which was in accord with the pesticide residue determination criteria and could be used for high throughput pesticide monitoring.