Determination of specific radioactivity of samarium-153 product. 1. Quantitative determination of samarium by spectrophotometry

On the specific radioactivity of Sm-153 for the radiotherapy of cancers, a simple method for determination of the amount of Sm was described. The method used Arsenazo III as a colorimetric reagent. The sample irradiated in the reactor was dissolved in 1M HCl solution. A small part of it was taken and mixed with Arsenazo III at pH 3.2, and the amount of Sm was determined by the spectrophotometric method at a wavelength of 652 nm. The molar absorptivity of Sm at 652 nm was 6.6x103 m-1·mm-1. The error of measurement in the partial different conditions was about 2% of the value determined. The effects of impurities, Fe, Zn and Cu mixing in the Sm during operation, were clarified. (author)