Flow injection analysis of three N-substituted phenothiazine drugs with amperometric detection at a carbon fibre array electrode

Abstract

The carbon fibre array electrode is demonstrated as a useful detector for flow injection analysis in the amperometric mode of detection.

A liquid chromatographic internal sampling valve was used to inject the sample into the supporting electrolyte stream and sampling rates as high as 200 samples per hour were feasible using a flow-rate of 1 ml min^–1. The oxidations of three pharmaceutically important phenothiazine drugs, namely perphenazine, triflupromazine. HCI and fluphenazine.2HCI, were investigated and an assay procedure was developed for these compounds and their formulations. Detection limits for the analytes were a few tenths of ananogram.