Photochemical–spectrofluorimetric determination of phenothiazine compounds by unsegmented-flow methods

Abstract

The properties of ultraviolet radiation were exploited to obtain fluorescent products from three phenothiazine compounds (chlorpromazine, promethazine and perphenazine). Photochemical reactions were studied and compared with chemical oxidation processes. After optimizing the working conditions, these reactions were applied to the determination of the analytes by stopped-flow injection methods (irradiation of the flow cell) and normal flow injection methods (irradiation of the reaction coil). The determination limits thereby achieved were 20 ng ml^–1(chlorpromazine and perphenazine) and 50 ng ml^–1(promethazine) with relative standard deviations of less than 2% in all instances (n= 11). Analyses for these compounds in pharmaceutical preparations were also carried out.