微乳液增敏4,5-二溴苯基荧光酮光度法测定镉

Spectrophotometric determination of cadmium with 4,5-dibromophenylfluorone using microemulsion enhanced sensitivity

研究在溴化十六烷基吡啶（CPB）-乳化剂OP-正丁醇-正庚烷-水5组分构成的微乳液介质中，镉（Ⅱ）与4，5-二溴苯基荧光酮（DBPF）的显色反应，建立了光度法测定镉的新方法；讨论了酸度、显色剂、表面活性剂和试剂加入顺序的影响。确定最佳实验条件。结果表明。在25mL显色液中镉量在0．0083～16μg范围内符合比尔定律，方法检出限为0．1μg／L，体系最大吸收波长为544nm，表观摩尔吸光系数ε=2．53×10^5L·mol^-l·cm^-1。本法已用于电镀废水和头发样品中镉（Ⅱ）的分析。

A new spectrophotometry for the determination of cadmium with 4,5-dibromophenylfluorone in the microemulsion medium of CPB - OP - n-C4H9OH - n-C7H16 - H2O was described. The factors such as acidity,chromogenic reagent, surfactant and the joining order of reagents were all studied,and the optimum conditions of reaction were determined.Beer＇ s law is obeyed in the range of 0.008 3～16 μg/25 mL, and the detection limit is 0.1 μg/L for cadmium（H）. The maximum absorption wavelength and apparent molar absorptivity are 544 nm and 2.53 × 10^5L·mol^-1·cm^-1, respectively. The method has been applied to the determination of Cd（Ⅱ） in electroplate wastewater and hair samples successfully.