INVESTIGATION OF THE EFFECT OF PH ON THE OPTICAL DENSITY OF THE CO(II)–5-CHLORO-8-HYDROXYQUINOLINE COMPLEX

This study investigates the formation conditions of the Co(II) ion complex with 5-chloro-8-hydroxyquinoline using a spectrophotometric method. The effect of solution pH on the opticaldensity of the formed complex was examined, and the maximum absorption wavelength as well asthe optimal complexation conditions were determined. The highest optical density was observed atλmax = 480 nm and pH = 5.0. The influence of buffer composition on the analytical signal was alsoevaluated, and the concentration range obeying the Beer–Lambert law was established. Theobtained results demonstrate that the Co(II)–5-chloro-8-hydroxyquinoline complex is sufficientlystable and can be successfully applied for the spectrophotometric determination of cobalt in variousanalytical samples.