Spectrophotometric Determination of Selenium in the Presence of Copper and Tellurium. Application to Anodic Slimes

Abstract

Selenite reacts with iodide ion quantitatively in acidic solution forming selenium and iodine. The iodine formed is extracted into chloroform phase and its absorbance is measured at 509nm. With this method 10^-2-5×10^-6M selenium could be determined. The interference of copper is removed by the precipitation of its hydroxide at pH 6-6.5 and 10^-4 M selenite could be determined with 1-4% relative error in the presence of 10^-2M copper and tellurium. This method is applied to anodic slime samples. The results are in accordance with the results obtained with different methods.