亮绿褪色反应用于微量季铵盐型阳离子表面活性剂的分光光度法测定研究

在 p H 7.0 0 Tris- HCl缓冲介质中 ,微量季铵盐型阳离子表面活性剂溴化十六烷基三甲胺 ( CTMAB)和溴化十六烷基吡啶 ( CPB)能使亮绿 ( Brilliant Green,简称 BG)产生灵敏的褪色反应 ,发现其褪色程度ΔA (ΔA =A0 - Ai)与 CTMAB及 CPB用量存在定量关系。研究了该褪色反应的最佳条件 ,探讨了反应机理 ,拟定了利用该反应用于微量 CTMAB和 CPB的测定方法 ,CTMAB和 CPB的浓度分别在0～ 6× 1 0 - 5mol/ L ,0～ 8× 1 0 - 5mol/ L范围内符合比耳定律。拟定的方法用于电镀废液样品中微量 CTMAB的测定 ,结果满意

A Study on the Determination of Trace Cetyltrimethylammonium on the Basis of the Discolor Reaction of Brilliant Green

Because of the function of the quaternary ammonium cationic surfactant of cetyltrimethylammonium bromide (CTMAB) or cetylpyridinium bromide (CPB) at pH 7.00 Tirs-HCl buffer solution, Brilliant Green produced a sensitive discolor reaction. Furthermore, it was found that the discolor degree of Brilliant Green had the quantitative relationship with micro-amount CTMAB or CPB. In this paper, the discolor reaction conditions for Brilliant Green-CTMAB system has been studied, and the discolor reaction mechanism has been discussed. Also, the methods for the determination of micro-amount CTMAB and CPB have been developed using the discolor reaction. It was found that the method had high sensitivity for the determination of CTMAB or CPB (εCTMAB=1.62×104L·mol-1·cm-1, εCPB=1.13×104L·mol-1·cm-1). Beer's law was obeyed in the range of 0～6.0×10-5 mol/L CTMAB and 0～8.0×10-5 mol/L CPB, respectively. The method has been applied satisfactorily to the determination of micro-amount CTMAB in electrodeposit waste water.