[Spectral study and determination of metoclopramide and procaine hydrochloride by sequential injection analysis]

A sequential injection spectrophotometric method is proposed for the determination of metoclopramide or procaine hydrochloride, based on the reactions of metoclopramide and procaine hydrochloride with cerium(IV) in sulfuric acid medium. Red intermediate products were observed and were found unstable so that their analytical use is only possible by sequential injection technology. For metoclopramide, the detection limit is 6.5 microg x mL(-1), and the linear range of determination is 9.7-116.6 microg x mL(-1) with a sampling frequency of 45 h(-1). For procaine hydrochloride, the detection limit is 7.4 microg x mL(-1), and the linear range of the determination is 10.0-130.0 microg x mL(-1) with a sampling frequency of 45 h(-1). The method has been applied to the determination of metoclopramide and procaine hydrochloride in tablets and injections with satisfactory results as compared with standard method.