快速协同浊点萃取-分光光度法测定水中六价铬

Determination of Cr(Ⅵ) in water with rapidly synergistic cloud point extraction-spectrophotom

目的建立快速协同浊点萃取-分光光度法测定六价铬的新方法。方法在强酸性条件下,Triton X-100与正辛醇形成快速浊点萃取体系,室温下溶液分为两相,Cr(Ⅵ)与PAN形成的金属螯合物进入富胶束相中,达到快速分离富集的目标,采用分光光度法直接测定富胶束相中富集的Cr(Ⅵ)。结果当Cr(Ⅵ)浓度为1.3μg/L^18.0μg/L时,吸光度值F与Cr(Ⅵ)浓度成线性关系,线性回归方程为y=0.008 5x+0.522 1,相关系数(r)为0.998,检出限为0.40μg/L,相对标准偏差为3.2%~5.3%。环境水样加标回收率为96.9%~103.9%。结论本方法所用仪器简单,操作方便,可用于实际水样中Cr(Ⅵ)含量的检测。

Objective To develop a novel method for the determination of chromium（ Ⅵ） by rapid synergistic cloud point extraction（ RS- CPE） coupled with spectrophotometry. Methods On the condition of strong acid,rapid synergistic cloud point extraction system was formed by Triton X- 100 solution and octanol. The complexationof Cr（ Ⅵ） with PAN in the system has enteredintorichmicellar phase at room temperature to achieve rapid separation and enrichment. Cr（ Ⅵ） in rich micellar phase was determined by spectrophotomentry. Results When the Cr（ Ⅵ） concentration was within 1. 3 μg / L ～ 18. 0 μg / L,the absorbance value of F and Cr（ VI） concentration was linear. The linear regression equation was y = 0. 008 5x ＋ 0. 522 1,and the correlation coefficient（ r） was 0. 998. The detection limits was 0. 40 μg / L,and the relative standard deviation（ RSD） was within 3. 2%- 5. 3%,and the recoveries of water samples were from 96. 9% to 103. 9%. Conclusion The method is simple and easy to operate,and can be applied to the determination of chromium（ Ⅵ） in water sample.