Pyridine-2-acetaldehyde salicyloylhydrazone as reagent for extractive and spectrophotometric determiantion of cobalt(II)at trace level

摘要

An extractive spectrophotometric method is described for the determination of cobalt (II) using pyridine-2-acetaldehyde salicyloylhydrazone (PASH) as reagent. For the extraction of cobalt (II) various experimental parameters such as acidity, reagent concentratio, equilibration time are systematically studied to establish optimum conditions for quantitative extraction. Cobalt (II) is extracted quantitatively in the pH range 1.0-4.0. The yellow coloured 1:2 metal:ligand complex in chloroform is determined spectrophotometrically at 415 nm. Beer's law was obeyed over the concentration range of 0.5-7.0 #mu#g mL~(-1) of cobalt (II). The molar absorptivity and Sandell sensitivity were found to be 1.04 X 10~4 L mol~(-1) cm~(-1) and 5.63 ng cm~(-2) respectively. The method is precise and simple. It was applied for the analysis of high speed steels and pharmaceutical samples for the estimation of cobalt (II).