分光光度法分析焦磷酸盐镀铜溶液中磷酸钾

Spectrophotometric Analysis of Potassium Phosphate in a P yrophosphate Copper Plating Bath

在pH≈4的条件下用醋酸锌沉淀焦磷酸盐镀铜溶液中的焦磷酸钾,过滤后在硫酸介质中,以抗坏血酸作还原剂,硝酸铋作催化剂,使磷酸与钼酸钠生成杂多酸蓝色络合物。用磷钼蓝光度法测定磷酸钾的质量浓度。铜离子和显色剂对测定的影响用参比液消除,在λ=660nm处测定吸光度。相对平均偏差为2.0%。回收率为97.8%～103%。

Potassium pyrophosphate forms zinc pyrophosphate deposit by ad ding zinc acetate to pyrophosphate copper plating solution under a condition of pH≈4.After filtration,phosphoric acid reacts with sodium molybdate to form bl ue heteropolyacid complex with cevitamic acid as reducing agent and bismuth nitr ate as catalyst,the concentration of potassium phosphate in the solution is mea sured by using a spectrophotometric method.Effects of the copper ions and colo r developing reagent on the measurement of potassium phosphate are eliminated by using reference solution,and the absorbence is measured at a wavelength of 660 nm.The relative average deviation of the method is 2.0%.The recovery ratio is 97.8% to 103%.