工业废水中阳离子表面活性剂的分光光度法测定

Spectrophotometric Determination of Cationic Surfactants in Industrial Waste Water

研究了阳离子表面活性剂溴化十六烷基三甲基胺和氯化十六烷基吡啶与二溴羧基苯基重氮氨基偶氮苯的显色反应 ,并提出了分光光度测定阳离子表面活性剂的新方法。结果表明 ,在碱性介质中 ,溴化十六烷基三甲基胺、氯化十六烷基吡啶等均能与二溴羧基苯基重氮氨基偶氮苯形成 1∶ 2的紫红色离子缔合物 ,最大吸收波长位于 5 80 nm处 ,表观摩尔吸光系数为 3.7× 1 0 4 L· mol- 1·cm- 1。表面活性剂的浓度在 0～ 80 μg/2 5 m L范围内符合比耳定律。方法直接应用于工业废水中阳离子表面活性剂的测定 。

A sensitive spectrophotometric method for the determination of cationic surfactants by chromogenic reagent dibromocarbaxylbenzenediazoaminoazobenzene (DBCDAA) has been developed. In pH 12.5～13.5 sodium hydroxide medium, cationic surfactants cethyltrimethylammonium bromide (CTMAB) or cetylpyridinium chloride (CPC) forms 1∶2 chromogenic complexes of ion association with DBCDAA which has an absorption maximum at 580nm. The molar absorptivity is 3.7×10 4 L·mol -1 ·cm -1 . Beer's law is obeyed for CTMAB (or CPC) in the concentration range 0～80 μg per 25 mL of solution. Trace amounts of cationic surfactant in industrial waste water have been determined well by the method.