Abstract
An electrolytic separation has been applied to the photometric determination of microgram quantities of cobalt in zirconium and titanium metal. A sulfuric acid solution containing 1g of the metals is electrolyzed with 2 ml of mercury as the cathode and a platinum spiral as the anode. The conditions of electrolysis are as follows: current strength, 2.0 amp; current density, 0.5 amp/cm2; electrolyte volume, 100 ml; acidity, 1.0 N; time of electrolysis 3hr. After electrolysis the mercury is drained out, distilled in a stream of nitrogen at 350°C, and the cobalt in the residue is determined by the photometric nitroso-R salt method. Tracer experiments using cobalt-60 indicate an exponential decrease in cobalt concentration of the electrolyte during the electrolysis, and an almost perfect recovery of cobalt under the prescribed conditions. One tenth to 5 ppm of cobalt can be determined with an accuracy of 0.1 ppm.
