FIA LIQUID-LIQUID-EXTRACTION SPECTROPHOTOMETRIC DETERMINATION OF PHENOTHIAZINE-DERIVATIVES IN PHARMACEUTICALS

The proposed extraction spectrophotometric determination of phenothiaz ine derivatives is based on the formation of ion associates of these d erivatives with chromazurol S. The determination is carried our by pow -injection analysis (FIA). Teflon separators constructed in the labora tory were tested. Three derivatives of phenothiazine-chlorpromazine, d iethazine, and fluphenazine-were analyzed as the substances and in pha rmaceutical form. The method provides correct and reproducible results . A very low detection limit and determination limit were attained (fo r diethazine, e.g., 0.04 mu g mL(-1) and 0.14 mu g mL(-1)), so that th e proposed method could also be used for monitoring small pharmaceutic al concentrations. The frequency of analysis is 15 samples per hour. ( C) 1996 John Wiley & Sons, Inc.