一次性滴管辅助的分散液液微萃取-气相色谱法快速测定环境水样中的氟虫腈及其代谢产物

Liquid-Liquid Micro-Extraction and Gas Chromatography-Electron Capture Detector for Rapid Determination of Fipronil and Its Metabolites in Environmental Water Samples

本研究建立了一种基于一次性滴管辅助的分散液液微萃取结合气相色谱-电子捕获检测器(GC-ECD)测定水中氟虫腈及其代谢产物的新方法。实验优化了一系列影响富集效率的参数,包括萃取剂种类和体积、分散剂的种类和体积、离子强度等。在优化的萃取条件下,4种目标分析物氟甲腈、氟虫腈亚砜、氟虫腈、氟虫腈砜的富集倍数在132~196之间,在20~10000 ng/L的浓度范围内线性关系良好,线性相关系数(r^(2))大于0.999,检出限在2.6~4.6 ng/L之间,定量限在8~15 ng/L之间。在加标量为0.1 ng/mL的浓度水平下,4种目标分析物回收率在85.8%~110.8%之间,相对标准偏差(RSD,n=3)小于8.0%。本方法前处理时间短,富集效率高,经济环保,为环境水样中氟虫腈及其代谢产物的测定提供了一种新选择。

In this study,a new method for separation and enrichment of fipronil and its metabolites in environmental water samples was developed based on disposable pipet assisted dispersive liquid-liquid microextraction(DPP-DLLME).In order to obtain higher detection sensitivity,parameters that might affect the enrichment performance of DPP-DLLME were optimized including the type and volume of extractant,the type and volume of dispersive solvent,the ionic strength of sampling solution.Under the optimized extraction conditions,the enrichment factors of four target analytes including fipronil desulfinyl,fipronil sulfide,fipronil and fipronil sulfone were in the range of 132-196.By coupling with gas chromatography-election capture detector(GC-ECD),a new method for analysis of fipronil and its metabolites in environmental water samples was established.The linear range was 20-10000 ng/L with correlation coefficient R^(2) higher than 0.999.The limits of detection for four target analyses were in the range of 2.6-4.6 ng/L,and the limits of quantitation were in the range of 8-15 ng/L.At the spiking concentration level of 0.1 ng/mL,the recoveries of the four target analytes in real environmental water samples ranged from 85.8%to 110.8%,and the RSDs were less than 8.0%.Finally,the established DPP-DLLME method was successfully applied to the detection of fipronil and its metabolites in several environmental water samples.