Investigation on the electrochemiluminescent behaviors of oxypurinol in alkaline Ru(bpy)2+3 solution using a flow injection analytical system

Electrochemiluminescent (ECL) behaviors of oxypurinol in alkaline tris(2,2-bipyridine)ruthenium(II) (Ru(bpy)(2+)(3) solution were studied in a flow injection electrochemiluminescent system (FI-ECL) in this paper. It was found that the ECL response of oxypurinol was significantly pH-dependent. It inhibited the ECL of Ru(bpy)(2+)(3) at <= pH 10.0, whereas exhibited enhanced ECL response at pH >= 11.0. 3 Additionally, other experimental conditions such as the applied potential of working electrode, the flow rate of carrier solution, and the concentration of Ru(bpy)(2+)(3) were all observed to affect the ECL response of oxypurinol. Under the optimum conditions, the logarithm of 3 enhanced ECL intensity, AL was found linearly proportional to the logarithm of oxypurinol concentration in the range of 1.0 X 10(-7)- 1.0 X 10(-4) mol L-1, and the detection limit (S/ = 3) was 3.0 x 10(-9) mol L-1. The mechanism of inhibited and enhanced Ru(bpy)(2+)(3) ECL by oxypurinol was studied, and a new and sensitive flow injection analysis (FIA) method basing on the enhanced ECL was proposed for detection of oxypurinol. (C) 2006 Elsevier B.V. All rights reserved.