Omeprazole (OPZ) as a high-efficiency coreactant in the electrochemiluminescence (ECL) of Ru(bpy)(3)(2+) on a bare Pt electrode has been studied in this paper. Based on the strong enhancement effect of OPZ on the ECL of Ru(bpy)(3)(2+), a simple, rapid and sensitive method for the determination of omeprazole has been established. Under the optimum conditions, the logarithmic ECL enhancement versus the logarithmic concentration of OPZ is linear over a wide concentration range of 2.0 x 10(-7) to 5.0 x 10(-4) M (r = 0.9945), with a detection limit of 2.0 x 10(-8) M (6.9 ng/mL, S/N = 3) in a pH = 11.5 100 mM phosphate buffer solution containing 1.0 x 10(-4) M Ru(bpy)(3)(2+). To demonstrate its applicability, the proposed method was applied in the determination of OPZ in capsules and the recoveries were ranged from 93.3%-106.7%. These provide a possibility to employ the new ECL method for OPZ detection in pharmaceutical preparations. According to the study of electrochemical behavior, ECL behavior and ECL emission spectrum of Ru(bpy)(3)(2+)/OPZ system, a possible ECL mechanism was proposed. (C) 2014 Elsevier Ltd. All rights reserved.