Amperometric Estimation of Cobalt in Presence of EDTA by Chloramine-T

Amperometric titration of Co(II) with two polarised electrodes at 100 mV has been carried out with chloramine-T in presence of EDTA at pH 2.0 to 6.5. Under ordinary conditions Co(II) is not oxidisable with usual oxidants, but EDTA forms complexes with Co(II) and Co (III), lowering the redox potential of dipositive cobalt to a point where it can be titrated with even mild oxidising agents like chloranrine-T.