Development of extractive spectrophotometric determination of Cobalt (II) using [N-(o– Methoxy benzaldehyde)-2–aminophenol] (NOMBAP) as an analytical reagent

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of Co (II) by using N-(o-methoxy benzaldehyde)-2-aminophenol (NOMBAP) as an analytical reagent. NOMBAP has been synthesized and characterized by elemental analysis. NOMBAP extracts Co (II) quantitatively (99.53%) into chloroform from an aqueous solution of pH range 8.2 – 9.5. The chloroform extract shows an intense peak at 490 nm (λ max). Beer's law is obeyed over the Co (II) concentration range 0.1 – 3.0μg/ml. The sandell's sensitivity and molar absorptivity for Co-NOMBAP system is 0.0425 μgcm⁻² and 1386 Lmole⁻¹cm⁻¹ respectively. The composition of extracted species is found to be 1:2 (Co:NOMBAP) by Job's Continuous Variation and Mole Ratio Method. The average of 10 determination of 10 μg of Co (II) in 10cm3 of solution is 9.96μg which is varied between 9.93 μg and 9.99 μg at 95% confidence limit and standard deviation is ±0.04. Interference by various ions has been studied. The proposed method has been successfully applied for determination of Co (II) in Alloy and Pharmaceutical samples.