VOLTAMMETRY OF POLYPROTIC ACIDS AT PLATINUM MICROELECTRODES - REDUCTION OF PYRIDOXAL-5'-PHOSPHATE

A voltammetric study of proton reduction from aqueous solution of pyri doxal-5'-phosphate (PLP) is carried out at Pt microdisc electrodes. St eady-state waves for the reduction of the solvated proton and some aci d forms of PLP are observed in the concentration interval investigated . The effect of the acid concentration, the electrode size and the inf luence of the supporting electrolyte on the limiting current, half-wav e potential and shape of the wave, are analyzed in view of theoretical predictions for strong and weak polyproptic acids. (C) 1997 Elsevier Science S.A.