水中铝的络合吸附极谱测定法

Determination of Aluminium(Ⅲ) in Water by Complex Adsorptive Polarogaphy

目的建立水样中微量铝的极谱分析方法。方法在HOAc-NH4OH缓冲液-铍试剂Ⅲ-乙二胺四乙酸(EDTA)体系中,采用极谱法测定水样中的铝,并探讨了最佳实验条件。结果在pH=5.8的HOAc-NH4OH缓冲液中,铝-铍试剂Ⅲ络合物于-0.54V产生1个灵敏的络合吸附极谱波。该方法的线性范围为0.005～0.300μg/ml;检出限为0.003μg/ml。相对标准偏差为5.4%～9.1%,回收率为92.7%～108.0%。结论该方法灵敏、准确,有较高的选择性,适用于水中铝的测定。

Objective To set up a method for determination of the trace amounts of aluminium(Ⅲ) in water samples. Methods Second derivative polarogaphy was used. Results In a solution of acetate buffer(HOAc-NH4OH, pH=5.8), Al(Ⅲ)reacted with Berllon Ⅲ to form a complex and a sensitive polarogaphic adsorptive wave appeared at -0.54 V(vs.SCE). By using the 2nd derivative polarogaphy measyrement, the wave height had a linear relationship with the concentration of Al(Ⅲ)in the range of 0.005-0.300 μg/ml. The limit of detection was 3.0 ng/ml. RSDs were 5.4%-9.1%. Recovery rates were 92.7%-108.0%. Conclusion The present method is sensitive, accurate with high selectivity and can be applied to the determination of the trace amounts of Aluminium(Ⅲ) in water sample with satisfactory results.