2-(2′-咪唑偶氮)苯酚-4-磺酸吸光光度法测定钴的研究

SPECTROPHOTOMETRIC STUDIES ON THE REACTION OF 2-(2'-IMIDAZOLYLAZO) PHENOL-4-SULFONIC ACID (IAP-4S) WITH CoⅡ AND ITS ANALYTICAL APPLICATION

研究了咪唑偶氮苯酚-4-磺酸(IAP-4S)与Co(Ⅱ)显色反应的适宜条件,应用拟定方法测定了钴镍混合试样中两组分的含量和标准合金样品中的钴含量,结果令人满意。

The reaction of IAP-4S with Co( Ⅱ ) and its analytical application have been studied. The optimum acidity for the complex reaction is pH 6. 0-12. 0. The reaction is completed within 2 min at room temperature. Bear's Law is obeyed for Co( Ⅱ ) in the range of 0-80μg/25ml. The molar absorptivity of the complex is 2. 3×104L ?mol-1 ?cm-1 at 578 nm. After the reaction is completed, the acidity was adjusted to below pH 1. 0 by adding HC1, then λ_(max), moved from 578 nm to 590 nm and the value for e changes to 1. 8×104, and the selectivity is much improved. The method has been applied to the determination of both Co( Ⅱ ) and Ni( Ⅱ ) in mixed solution, as well as of Co in two kinds of alloy, with satisfactory results.