Studies on quantitative separation of cerium with potassium iodate

The quantitative determination of cerium (IV) in nitric acid solution by precipitation as iodate from other lanthanide elements can be carried out with good accuracy. But it requires much time and labor for washing of the precipitate, etc. Therefore, the so-called precipitation from homogeneous solution has been investigated, using 144Ce and 46Sc as the tracers. It was found that the formation of the precipitate was the best by using 3N HNO3 solution. Futher investigation showed that the best precipitation method is carried out by the following method. Namely, at first, cerium (IV) should be reduced to cerium (III) by hydrogen peroxide, then potassium iodate and potassium bromate are dissolved at room temperature, and the solution is heated on a water bath for gradual formation of the precipitate of cerium which can be filtered and washed in a short time.