Fe_(3)O_(4)/g-C_(3)N_(4)磁性固相萃取湖水中的3种苯甲酰脲杀虫剂

Determination of Benzoylurea Insecticides in Lake Water with Fe_(3)O_(4)/g-C_(3)N_(4) Based Magnetic Solid Phase Extraction

建立了Fe_(3)O_(4)/g-C_(3)N_(4)磁性固相萃取,结合高效液相色谱-可变波长紫外检测,用于测定湖水中3种苯甲酰脲杀虫剂的新方法。实验考察了溶液pH、离子强度、吸附剂用量、吸附时间、洗脱溶剂种类和体积对3种目标物回收率的影响。在最优实验条件下,氟铃脲和虱螨脲在0.50~500 ng/mL(r≥0.9997)、氟啶脲在0.20~200 ng/mL(r=0.9999)范围内线性关系良好,检出限(S/N=3)和定量限(S/N=10)分别为0.05~0.15 ng/mL和0.20~0.50 ng/mL。3个加标水平的回收率为74.6%~102%,日内和日间精密度(n=3)分别为1.9%~5.3%和2.2%~9.0%。当上样体积为30 mL时,Fe_(3)O_(4)/g-C_(3)N_(4)对湖水中3种苯甲酰脲杀虫剂有效富集达112~153倍。吸附剂重复使用10次时,目标物回收率的相对标准偏差≤9.8%。本方法高效经济,可用于湖水中苯甲酰脲杀虫剂的分离分析。

A method of magnetic solid phase extraction using magnetic carbon nitride composite(Fe_(3)O_(4)/g-C_(3)N_(4))coupled to high performance liquid chromatography-variable wavelength detection was developed for the determination of three kinds of benzoylurea insecticides(hexaflumuron,lufenuron and chlorfluazuron)in lake water samples.The main extraction parameters,including pH and ionic strength of solution,amount of sorbent,extraction time,eluting solvent and eluting volume were investigated.Under the optimized conditions,the proposed method gave the linear ranges of 0.50-500 ng/mL(r≥0.9997)for hexaflumuron and lufenuron,and 0.20-200 ng/mL(r=0.9999)for chlorfluazuron.The limits of detection(S/N=3)and limits of quantification(S/N=10)ranged from 0.05 to 0.15 ng/mL and 0.20 to 0.50 ng/mL,respectively.The recoveries at three spiked levels were 74.6%-102%,and the intra-day and inter-day precisions varied from 1.9%to 5.3%and 2.2%to 9.0%,respectively.Besides,the enhancement factor of 112-153 was achieved for all the analytes when 30 mL of the lake water was loaded.The sorbent was stable enough for ten replicate cycles of extraction/desorption with relative standard deviations≤9.8%.The method could be applied for the determination of benzoylurea insecticides in lake water due to its high efficiency and low consumption.