Determination of Cobalt in Cobalt(III) Complexes - A Comparative Study

Cobalt in cobalt(III) complexes was determined by a gravimetric method, weighing cobalt as cobalt(II) sulfate after heating the complexes with concentrated sulfuric acid; by a spectrophotometric method, measuring the color of cobalt(II)-thiocyanate complex in water-acetone mixture after reducing cobalt(III) to cobalt(II) with chromium(II), and by atomic absorption. The three methods were compared for accuracy of results and for convenience in routine analysis