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 KMnO(4) 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 ml(-1) (9.8 × 10(-8) - 2.5 × 10(-6) mol L(-1)) with a detection limit (S/N=3) of 0.025 µgml(-1) (6.2 × 10(-8) mol L(-1)). The relative standard deviation of the proposed method calculated from 10 replicate injections of 0.4 µg ml(-1) carvedilol is 0.95%. The sample throughput is 90 samples h(-1). The method is applied successfully to the determination of carvedilol in tablets dosage form and spiked human plasma.