分光光度法与滴定法测定V3+/VO2+混合溶液钒离子浓度的对比研究

Comparative Study on the Spectrophotometry and Titration Methods for Determining Vanadium Ion Concentration in V/VO Mixed Solution

采用分光光度法,分别建立V3+和VO2+的标准曲线,并针对钒电池常用的V3+/VO2+混合溶液,测定未知样品V3+和VO2+的浓度,再进行加和获得总钒浓度。同时,采用氧化还原滴定方法,获得未知溶液的总钒浓度,对二者进行对比分析。结果表明:分光光度法与滴定法获得的总钒浓度差异较小,平均为0.008 mol·L-1;以分光光度法为基准,测定样品相对标准偏差(n=6)为1.0128%,可以满足钒电池电解液中钒离子浓度快速准确分析的需要。

The standard curves of V3+and VO2+were established respectively by spectrophotometry,and the concentrations of V3+and VO2+of unknown samples were measured for the V3+and VO2+mixed solution of VRFB.Then the total vanadium concentration was obtained by adding the concentrations of V3+and VO2+.At the same time,the total vanadium concentration of unknown solution was obtained by oxidation-reduction titration.The results showed that the obtained difference of the total vanadium ion concentration between spectrophotometry and titration method was small,with an average of 0.008 mol·L-1.The relative standard deviation(n=6)was 1.0128%based on spectrophotometry,which can meet the needs of vanadium ion concentration analysis in vanadium battery electrolyte.