A spectrofluorimetric determination of phenothiazine derivatives after their photooxidation or chemical or electrochemical oxidation in a flow injection arrangement

► Three modes of generating a phenothiazine radical-cation for FIA with spectrofluorimetric detection are compared. ► A thin-layer electrochemical flow-through cell is adopted for generation of the phenothiazine radical-cation. ► The detection limit of 2.6 ng/mL of chlorpromazine was attained in the photooxidation mode. ► The method was applied to determination of phenothiazines in medicinal preparations.