自动电位滴定直接测定含锰粗钴盐中常量钴

Direct determination of cobalt in crude cobalt salts containing manganese by automatic potentiometric titration

研究了电位滴定法测定含锰粗制碳酸钴、粗氢氧化钴中钴量的方法。通过溶解样品时,加入高氯酸和磷酸,使锰(Ⅱ)氧化后生成磷酸锰(Ⅲ),消除了锰对钴测定的干扰。试验结果表明:在拟定条件下80mg锰不干扰钴的测定,样品分析的精密度RSD<0.3%,加标回收率99.56%～100.15%,与其他方法的对照结果一致,满足常量钴测定要求。

When the samples were dissolved,perchloric acid and phosphoric acid were added to oxidize manganese(II)to manganese(III)phosphate,which eliminates the interference of manganese on the determination of cobalt.The test results showed that under the proposed conditions,no significant interferences were brought by 80 mg manganese for the determination of cobalt.The precision of sample analysis based on RSD test was below 0.3%,and the recoveries were in the range of 99.56%—100.15%.The results were in consistent with the results determined by other methods and could meet the requirements of cobalt determination in macro amount.