【摘要】 建立了功能化离子液体/离子液体分散液-液微萃取(FIL/IL-DLLME)测定水中4种苯氧羧酸类除草剂的农药残留分析方法。离子液体[C4MIMBF4]有助于难溶于水的[C6Hy MIMTf2N]在水相中形成液滴。离子对[Li Tf2N]的引入有利于提高功能离子液体对分析物的提取效率,对影响萃取效率的重要因素进行选择和优化,最佳条件为:100μL[C6Hy MIMTf2N])作为提取剂,100μL[C4MIMBF4]作为分散剂,在30℃下超声5 min,[Li Tf2N]浓度为5%和样品溶液的p H=2。在最佳优化条件下,5~500μg/L范围内线性良好,相关系数为0.9953~0.9996;对自来水、河水、田间水进行浓度为10和20μg/L添加回收实验,回收率为70.2%~107.5%,相对标准偏差RSD<10%,检出限为0.05~0.2μg/L,得到满意的结果,说明本方法对于实际样本的检测具有可行性。更多还原

【Abstract】 Functionalized ionic liquid / ionic liquid ultrasound-assisted dispersive liquid-liquid microextraction( FIL/IL-DLLME) was developed for the determination of four phenoxy herbicides in water samples. The extraction procedure was induced by the formation of cloudy solution,which was composed of fine drops of[C6Hy MIMTf2N],dispersed entirely into sample solution with the help of hydrophilic [C4MIMBF4]. The introduction of ion-pairing agent( [Li Tf2N]) was beneficial to the improvement of the extraction efficiency.The main parameters relevant to this method were investigated and optimized as follows: 100 μL of[C6Hy MIMTf2N] and 100 μL of [C4MIMBF4]were used as extraction solvent and dispersion,the ultrasonic time was fixed for 2 min at 30℃,6% [Li Tf2N]was added and the p H of sample solution was adjusted to 2.Under the optimum conditions, the linear correlation coefficient ranged from 0. 9953 to 0. 9996 for concentration levels of 5- 500 μg / L and the limits of detection( LODs) for the herbicides were between0. 05 μg / L and 0. 2 μg / L. The recoveries( 70. 2%- 107. 5%) of the target analytes were obtained in tap water,river water and field water at two spiked levels of 10 and 20 μg / L,the relative standard deviations( RSDs,n =6) were less than 10%,The results indicated that the proposed method was effective for the determination of phenoxy acid herbicides in water samples.更多还原