5-Br-PADAP光度法同时测定微量钴、镍

Simultaneous Determination of Trace Co and Ni with 5-Br-PADAP

本文在酒石酸存在的氨性溶液中,加入焦性没食子酸掩蔽铁,利用EDTA对金属离子络合的差异性,破坏干扰元素与显色剂的络合物而定量保留钴、镍与显色剂的络合物;提高方法的选择性。选择适当的萃取剂增大钴,镍吸收光谱的差异性,结合计算分析消除同一体系中钴、镍相互干扰、实现钴、镍的同时测定。方法用于GSS、GSR系列标样和多种地质试样分析。结果满意。

A spectrophotometric method is described for the simultaneous determination of Co and Ni.Co,Ni and interfering elements are allowed to react with 5-Br-PADAP in the presence of tarfcaric acid at pH>8,then EDTA is added to destroy the interfering complexes while the complexes of Co and Ni remain untouched. The absorbances of the mixture of two complexes are measured at 8 wavelengths. Then the concentration equations are solved with least squares method to obtain the concentration of Co and Ni respectively. The method has been satisfactorily applied to the determination of Co and Ni in geological samples.