Flow-injection chemiluminometric analysis of some benzamides by their sensitizing effect on the cerium-sulphite reaction

A simple, highly sensitive chemiluminescent method using flow injection is described for the determination of three substituted benzamides, namely: sulpiride, sultopride and tiapride. The method is based on the sensitizing effect of these drugs on the chemiluminometric oxidation of sulphite by cerium(IV). The different experimental parameters affecting the chemiluminescence intensity were carefully studied and incorporated into the procedure. The method permits the determination of 0.05–2.5 μg ml−1 sulpiride, 0.01–2.5 μg ml−1 sultopride hydrochloride and 0.01–1.5 μg ml−1 tiapride hydrochloride with minimum detectability of 0.01 μg ml−1. The method was applied to the determination of these benzamides in pharmaceutical preparations and biological fluids.