混合表面活性剂增敏铬天青S分光光度法测定锌阳极板中痕量铝

Spectrophotometeric determination of trace aluminium in zinc-anode board with enhanced sensitivity of mixed surfactants

以铬天青S（CAS）为显色剂，CTMAB和PVA组成的混合表面活性剂为增敏剂，采用分光光度法测定了锌阳极板中痕量铝含量。探讨了铝与铬天青（CAS）的反应和显色条件，着重考察了不同的表面活性剂对体系的增敏作用。结果表明，在溴化十六烷基三甲胺（CTMAB）和聚乙烯醇（PVA）存在下和pH 6.6的乙酸铵-乙酸缓冲介质中，铝与CAS反应生成有色络合物，络合物的最大吸收波长位于629 nm处，表观摩尔吸光系数为1.46×10^5L·mol^-1·cm^-1，铝离子的质量浓度在0-400μg/L的范围内服从比尔定律。方法用于锌阳极板中铝的测定，样品加标回收率为95.5%-100.5%。

Trace aluminum in zinc-anode board was determined by spectrophotometry with chrome azurol S （CAS） as colored reagent and CTMAB and PVA mixed surfactants as enhanced sensitivity agent. The color reaction conditions of aluminium with CAS were investigated, laying emphasis on enhanced sensitivity effect of surfactants on the determination system. The results showed that aluminium reacts with CAS to form a colored complex in the NH4Ac-HAc buffer solution at pH6.6 and in the presence of CTMAB and PVA, whose the maximum absorption wavelength is located at 629nm. The apparent molar absorption coefficient is 1.46×10^5L·mol^-1·cm^-1. Beer s law is obeyed in the mass concentration range of 0-400μ/L for aluminium. The method has been applied to the determination of trace aluminium in zinc-anode board with the addition standard recoveries of 95.5%-100. 5%.