双水相三元络合物萃取光度法测定废水中痕量银

Determination of Trace Silver in Wastewater by Spectrophotometry Connected Ternary Complex Aqueous Two-Phase Extraction

本文研究了聚乙二醇2000-硫酸铵双水相体系对银-碘-结晶紫三元络合物的萃取性能,建立了双水相三元络合物萃取光度法测定银的新方法。对双水相体系中聚乙二醇、硫酸铵和络合剂的用量及溶液酸度进行了优化,考察了共存离子对Ag(Ⅰ)测定的影响。最佳实验条件下,方法的线性范围为10.0~700μg·L-1(r=0.9998),检出限2.8μg·L^(-1),加标回收率在97.5%~104.0%之间,相对标准偏差在2.4%~3.3%之间。方法已成功应用于工业废水分析。

A procedure for the determination of silver by spectrophotometry was developed after the silver iodine-crystal violet ternary complex was extracted by a two-aqueous phase system formed by polyethylene glycol and ammonium sulphate. Amounts of polyethylene glycol solution, ammonium sulphate, complexing agent solution and the acidity of the system were optimized. The interference effects of various coexistent ions were studied. Under the optimum conditions, a good linear relationship was obtained in the range of 10.0~700μg/L of the silver (r=0.9997), the detection limits was 2.8μg/L. The recoveries fell in the range was 97.5%~104.0% and the relative standard deviations were between 2.4% ~3.3%. This method had been applied for the determination of silver in industrial wastewater with satisfactory results.