Electrochemiluminescent behavior of allopurinol in the presence of Ru(bpy)32+

The electrochemiluminescent (ECL) response of allopurinol was studied in aqueous media over a wide pH range (pH 2-13) using flow injection (FI) analysis. It was revealed that allopurinol itself had no ECL activity, but could greatly enhance the ECL of Ru(bpy)32+ in alkaline media giving rise to a sensitive FI-ECL response. The effects of experimental conditions including the mode of applied voltage signal, the potential of working electrode, pH value, the flow rate of carrier solution, and the concentration of Ru(bpy)32+ and allopurinol on the ECL intensity were investigated in detail. The most sensitive FI-ECL response of allopurinol was found at pH 12.0, where the FIA-ECL intensity showed a linear relationship with concentration of allopurinol in the range 1 × 10−8 mol L−1 to 5 × 10−7 mol L−1, and the detection limit was 5 × 10−9 mol L−1.