Flow injection-spectrophotometric determination of metoclopramide hydrochloride.

The determination of metoclopramide hydrochloride is spectrophotometrically determined by the Bratton-Marshall method in a flow injection assembly. The required nitrite is prepared on-line in the flow assembly by reducing a nitrate solution with the aid of a copperised cadmium solid-phase reactor. The calibration graph is linear over the range 0.5-85 mg l(-1), with a relative standard deviation (RSD) of 0.89%, and sample throughput of 51 samples h(-1). The method is easy and simple, and it is applied to determination of metoclopramide in some pharmaceutical formulations. The method eliminates the need for frequent preparation of unstable nitrite solutions.