疏水性低共熔溶剂超声辅助分散液液微萃取高效液相色谱法测定环境水中的除草剂残留

Ultrasonic Assisted Dispersive Liquid-liquid Microextraction Based on Hydrophobic Deep Eutectic Solvent for the Determination of Herbicide Residues in Environmental Water Samples by HPLC

建立了疏水性低共熔溶剂超声辅助分散液液微萃取(DES-UA-DLLME)高效液相色谱法测定环境水中除草剂的农药残留分析方法。通过对不同种类低共熔溶剂的萃取效率进行筛选,以正癸酸(氢键给体)与氯化四丁基铵(氢键受体)在物质的量比为3∶1形成的疏水性低共熔溶剂萃取效率最高,并且对影响萃取的一些参数(DES的体积、超声萃取时间、离心时间以及水样pH等)进行优化。在最优条件下,7种除草剂的最小检出限和定量限分别为0.026~0.057μg/L和0.09~0.19μg/L,添加回收率和相对标准偏差(RSD)分别为80.5%~97.6%和2.8%~7.8%,并且应用于实际环境样本中7种除草剂的检测,同时进行不同浓度添加回收率实验,回收率为85.0%~99.3%,能够满足农药残留分析要求。

An ultrasound assisted dispersive liquid-liquid micextraction method based on hydrophobic deep eutectic solvent(DESUA-DLLME)was developed for the determination of herbicide residues in environmental water samples by high performance liquid chromatography(HPLC).The types of deep eutectic solvents were selected for high extraction efficiencies and DES composed of n-decanoic acid and tetrabutylammonium chlorid at 3∶1 molar ratio provided higher extraction efficiencies.Several important factors affecting extraction efficiency conditions,including the volume of DES,ultrasonic time,centrifuge time and sample pH were optimized.Under the optimized conditions,limits of detection and limits of quantification of seven herbicides were in the range of 0.026~0.057μg/L and 0.09~0.19μg/L,respectively.The recoveries were ranged from 80.5%to 97.6%,and the relative standard deviations(RSD)were between 2.8%and 7.8%.Finally the developed method was successfully applied for determination of seven herbicides from several real environmental water samples.Then the proposed method on the real water samples was demonstrated by spiking the samples at different concentrations.The average recoveries were 85.0%~99.3%which could meet the requirements of pesticide residue analysis.