Abstract:

The method of pretreatment for transforming polynuclear aluminum into mononuclear aluminum in water samples has been studied. The samples are heated in a water bath at 40 ℃for 10 min with proper amount of (1+3) HCl, and then the mononuclear aluminum is dissociated. The color system of Al(Ⅲ)-CAS-CPB-NP is used for determining mononuclear aluminum. In a medium of mixed surfactants of CPB-NP, Al(Ⅲ) reacts with CAS to form a stable violet-blue complex at pH 5.15. The maximum absorption wave of the complex locates at 625 nm and the molar absorptivity is 9.41×10⁴ L/(mol·cm). Beer’s lawis obeyed in the range of 0-0.12 mg/L for aluminum. This method has been applied tothe determination ofaluminumin water samples with satisfactoryresults.

Key words: spectrophotometry, mononuclear aluminum, polynuclear aluminum

摘要：

研究了将水样中的多核铝转化为单核铝的预处理方法，即加入适量(1+3)HCl，于40℃水浴中加热10min，便可破坏水样中的羟基聚合铝，使单核铝游离出来。采用Al(Ⅲ)-CAS-CPB-NP显色体系测定铝。结果表明，在混合表面活性剂CPB-NP存在下，铝与铬天青S在HAc-NaAc介质中形成蓝紫色配合物，其最大吸收波长为625 nm，表观摩尔吸光系数为9.41×104 L/(mol.cm)，线性范围为0～0.12 mg/L。该法可用于水样中单核铝与多核铝的测定。

关键词: 分光光度法, 单核铝, 多核铝

CLC Number: 

• O661

• O657.32