7-(苯偶氮)-8-羟基喹啉-5-磺酸钠-溴化十六烷基三甲基铵与铜的显色反应研究

STUDY ON THE CHROMOGENIC REACTION OF COPPER WITH SODIUM 7- (1-PHENYLAZO)-8-HYDROXYQUINOLINE-5-SULFONATE

研究了铜与 7- (苯偶氮 ) - 8-羟基喹啉 - 5-磺酸钠 ( PAHQS)的显色反应 ,发现 Cu( )与PAHQS形成棕黄色配合物 ,在表面活性剂溴化十六烷基三甲基铵 ( CTMAB)存在下 ,对配合物及PAHQS有明显的增溶增敏作用。在 p H3.3的邻苯二甲酸氢钾 -盐酸缓冲溶液中 ,配合物最大吸收峰位于 460 nm处 ,其表观摩尔吸光系数为 6.0 4× 1 0 4 L·mol-1· cm-1,铜浓度在 0～ 50 μg/2 5ml范围内符合比耳定律 ,方法应用于中药和环境水样中痕量铜的分析 。

A new chromogenic system for the determination of copper with sodium 7-(1-phenylazo)-8-hydroxyquinoline-5-sulfonate (PAHQS) is reported. In a KHC 8H 4O 4-HCl buffer solution (pH 3.3), copper(Ⅱ) reacts with PAHQS to form a brownish yellow complex. In the presence of CTMAB, remarkable solubilization and hyperchromic effect on the chromogenic system are observed. The absorption maxima of the complex is found at 460nm, and its apparent molar absorptivity is 6.04×10 4L·mol -1 ·cm -1 . Beer′s law is obeyed over the range 0~50μg/25ml for copper(Ⅱ). The method has been applied sotisfactorily to the determination of trace amounts of copper in environmental and Chinese traditional drug samples.