Sensitive Assay for Carvedilol in Tablets and Spiked Human Plasma Using a Flow-Injection Chemiluminometric Method

A simple and sensitive chemiluminometric method using flow injection (FI) is developed for the determination of carvedilol, based on the reaction of carvedilol with tris (2, 2’-bipyridyl) ruthenium (II), and KMnO4 in sulfuric acid medium. Under the optimum conditions; the chemiluminescence (CL) intensity is a linear function of carvedilol concentration over the range of 0.04–1.0 μg mlˉ1 (9.8 × 10ˉ8 - 2.5 × 10ˉ6 mol Lˉ1) with a detection limit (S/N=3) of 0.025 μgmlˉ1 (6.2 × 10ˉ8 mol Lˉ1). The relative standard deviation of the proposed method calculated from 10 replicate injections of 0.4 μg mlˉ1 carvedilol is 0.95%. The sample throughput is 90 samples hˉ1. The method is applied successfully to the determination of carvedilol in tablets dosage form and spiked human plasma.