Studies on the Determination of Metals by Extraction Method of Metal Organic Compound. VI : Determination of Cobalt with Antipyrine

Cobalt forms blue colored solution or precipitation with antipyrine in the presence of ammonium thiocyanate, and this colored compound can be extracted with organic solvents. Hence its absorbancy was measured by the Beckman Model DU spectrophotometer and the microdetermination of cobalt was perfomed. The extraction could be effected with amyl acetate, ethyl acetate, amyl alcohol, chloroform, or benzene, but not with carbon tetrachloride, xylene, or toluene. By determining the absorption at the wavelength 630 mμ, 1～100γ of cobalt could be determined and the elements interfeing in this determination were chiefly iron, copper and bismuth