The behavior of anodic electrochemiluminescence (ECL) of luminol in alkaline solution at a polycrystalline platinum electrode was studied. It was found that the ECL intensity and peak shape were related to pre-polarization of the platinum electrode and oxygen dissolved in the solution. Furthermore, the surface state of platinum electrode was detected under different conditions by XPS and CV characteristics of Pt and Pt|S~a~d~s electrodes. The possible mechanism for the two anodic ECL channels is proposed: (1)Two conditions are necessary for formation of the anodic ECL shoulder peak at 0.22V(vs.Ag). One is the oxygen dissolved in solution and another is that there are fresh Pt atom sites on the electrode surface. The luminol anion is electro-oxidized to luminol radical, which can react with dissolved oxygen to generate light emission. (2) Platinum oxides on the electrode surface can accelerate the producing rate of atomic oxygen. This leads to the enhancement of ECL intensity of the peak near 0.60V(vs.Ag).

Key words: LUMINOL, POLYCRYSTAL, PLATIMUM ELECTRODE, ANODES, ELECTROLUMINESCENCE, LUMINOUS MECHANISM