库仑分析法测定富铬酵母中铬含量研究

Determination of Chromium Content in Chromium-rich Yeast by Coulometry

在1mol/L硫酸-磷酸(1∶1混合)溶液中电解0.5mol/L Fe2(SO4)3溶液,使Pt电极上产生Fe2+,与经过消化氧化后样品中的6价铬发生氧化还原反应,采用永停法控制滴定终点,根据电解定律计算铬的含量。该方法测定结果与光度法一致,加标回收率在99%～103%之间,可用于富铬酵母中铬含量的测定。

The solution of 0. 5 mol/L Fe2 （SO4）3 is electrolyzed in the medium of 1 mol/L H=SO4- H3PO4（1： 1） to generate Fe2＋ on Pt electrode, and occur redox reaction with Cr （Vl） in the sample, dead-stop method is used for the detection of end point of coulometric titration, to calculate chromium content on the basis of Law of Electrolysis. The result of detection is identical with spectrophotome- try, the recovery of sample is within 99 %-103 %, this method is used for the detection of chromium content in chromium-rich yeast.