高纯碳酸锂中痕量磷、砷的孔雀绿-磷(砷)酸钼浮膜分光光度法测定

Determination of Microamounts of Phosphorus and Arsenic in High Pure Lithium Carbonate by Flotation spectrophotometry

本文研究了孔雀绿与磷(砷)酸钼离子对膜的形成条件,并依此与基体分离,进行痕量磷、砷的浮膜-分光光度法测定。选用硫酸为介质,考察了25种共存离子对测定的影响。拟定了高纯碳酸锂中痕量磷、砷的分析方法,操作简便,结果令人满意。

A sensitive and accurate method is described for the determination of P and As in high-pure Li_2CO_3 using Malachite Green as an ion-pair reagent.The formation of ion-pair membrane of Malachite Green with-Molydo- phosphate(Molydoarsenic)and the spectrophotometric determiation of P and As are investigeted.The methanol is added to dissolve the floated ion pair.The determination is performed in the organic phase.The apparent molar ab- sorptivity is 2.95×10~5L·mol^(-1)·cm^(-1) for P and 1.8× 10~5L· mol^(-1)·cm^(-1) for As.Beer's law is obeyed in the range from 0 to 8μg/25mL p and from 0 to 6μg/25mL As.In a medium of H_2SO_4,the effect of 25 ions has been studied and it has been found that many ions do not inter- fere.The method is simple and the analytical results are satisfactory.