Abstract
Reaction of 2-benzothiazolyl-phenylketoxime with Co2+ gave a yellow-orange coloration and that with Cu2+ and Ni2+ gave a yellow coloration. Two cc of sample solution in a 5 cc measuring flask were treated with 0.5 cc ammonia-ammonium chloride buffer solution of pH 9.00, 1 cc 0.2% ethanolic solution of the reagent and 1.5 cc dioxane, made up to 5 cc, and the light absorbancies at 362mμ for copper, 358mμ for cobalt, and 356mμ for nickel were measured after standing for 30 min, running a blank consisting of the same amount of the reagent, the buffer solution, ethanol and water at the same time.
By this method, estimation of copper in the range of 0.2520.20γ/cc, cobalt in the range of 0.110.65γ/cc, and nickel in the range of 0.2510.40γ/cc was possible.
Also, selective determinations of copper, cobalt and nickel from their mixture were possible by selecting the pH and the wavelengths as 400mμ or 445mμ. The presence of palladium, and cobalt for determination of copper, that of palladium and silver for cobalt, and that of iron, palladium and cadmium for nickel had disturbing influences. The molecular absorption coefficient was 1.303×104 for copper, 2.178×104 for cobalt, and 1.899×104 for nickel.
