Spectrophotometric and AAS determination of trace amounts of cobalt after preconcentration by using α-benzilmonoxime-microcrystalline naphthalene

Abstract

The formed cobalt-α-benzilmonoxime complex was adsorbed onto microcrystalline naphthalene. Then it was determined by zero and first derivative spectrophotometry and by atomic absorption spectrophotometry (AAS) after dissolving into chloroform and methylisobutylketone (MIBK), respectively. Under optimum conditions, cobalt in the range of 1.0 - 20.0, 0.4 - 30.0 and 2.5 - 50.0 μg could be determined by spectrophotometry, first derivative spectrophotometry and AAS method, respectively. By the method, a preconcentration factor equal to ∼30 for cobalt was obtained. The effect of diverse ions on the determination of 5.0 μg cobalt was also studied. The method was successfully applied to some pharmaceuticals and synthetic alloy samples.