双波长分光光度法测定铜及其络合物特征参数

Dual-Wavelength Spectrophotometric Determination of Copper and Its Complex's Characteristic Parameters with Sulphochlorophenol S

在ｐＨ４．５醋酸盐缓冲溶液中，铜（Ⅱ）与氯磺酚Ｓ（ＳＣＰＳ）发生灵敏显色反应，生成蓝色络合物。本文应用β修正光度分析原理，研究此显色反应双波长测定废水中微量铜，分析灵敏度和准确度均比普通光度法有所提高，而且，络合物的络合比，实际摩尔吸光系数和不稳定常数均能够准确而简单地测得。结果表明，在铜浓度为０－０．８０ｍｇ／Ｌ范围内，符合朗白－比尔定律，铜最低测定浓度为０．０３ｍｇ／Ｌ。对样品分析，铜的加标回收率为９３．５％—１０９％，相对标准偏差ＲＳＤ≤３．７％。

Copper (Ⅱ)can react with sulphochlorophenol S (SCPS) at pH 4. 5 to change the coloured solution from red to blue. In this paper,β-correction spectrophotometric principle has been applied for the determination of trace copper in waste water using the above reaction. The sensitivity and accuracy were both higher than that by the ordinary spectrophotometry. In addition, the complex's characteristic parameters can be determined accurately and easily, for example the composition ratio, practical molar absorptivity and instability constant. Results showed that Beer's law is obeyed over the concentration range 0-0. 80mg/L copper with the detection limit to be equal to 0. 03 mg/L. The analysis of practical samples resulted the recovery of copper is between 93.5 and 109% and the relative standard deviation(RSD) less than 3.7%.