液液微萃取火焰原子吸收法测定污水中的Cd和Ni

Liquid-Liquid Microextraction and Flame Atomic Absorption Spectrometry for Determination of Cadmium(Ⅱ) and Nickel(Ⅱ) in Wastewater

基于分散液液微萃取，建立了一种简单、快速、环保的涡流辅助-表面活性剂增强乳化-分散液液微萃取原子吸收测定污水中的Cd和Ni的方法。该方法中，萃取剂在涡旋器的辅助下分散到水溶液中，同时表面活性剂作为乳化剂，加速了分析物从水溶液中转移到萃取剂中。对影响该方法的主要因素进行了研究，得到的最佳优化条件为：萃取剂1-溴-3-甲基丁烷的体积为60μL，表面活性剂Triton X—114的浓度为0．2mmol／L，提取时间为1min。在优化条件下得到的富集倍数为211～214，线性范围为1～600μg/L，Cd和Ni的检出限分别为0．16μg／L和0．25μg/L。该方法的加标回收率为92％～102％，相对标准偏差为1．19％～1．58％。

A simple, fast and environmentally friendly method for the determination of cadmium （ Ⅱ ） and nickel （ Ⅱ） in wastewater using vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction （VSLLME） combined with flame atomic absorption spectrometry （FAAS） was developed. In the established method, the dispersant dissolved into the aqueous solution by the vortex agitator. Meanwhile, a snrfactant which was used as an emulsifier, promoted the transfer of analytes from aqueous solution to the extractant. The main factors affecting the method were studied. The optimal conditions were obtained as follows ： 60 μL of 1-bromo-3-methylbutane used as extractant, 0.2 mmol/L of Triton X- 114 used as surfactant and 60 s of extraction time. Under the optimal conditions, enrichment factor reached 211 to 214, the calibration curve was linear in the range of 1 to 600μg/L, the detection limits of Cd and Ni were 0.16 μg/L and 0.25 μg/L. The recoveries ranged from 92% to 102% , and the relative standard deviation （RSD） was in the range of 1.19% to 1.58%.