APPLICATION OF HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH DIODE-ARRAY DETECTION AND ONLINE POSTCOLUMN PHOTOCHEMICAL DERIVATIZATION TO THE DETERMINATION OF ANALGESICS

HPLC analyses of pharmaceutical dosage forms containing analgesics and related compounds (acetylsalicyclic acid, paracetamol, propyphenazone , caffeine and chlorpheniramine) were performed on C-18 and cyano colu mns under reversed-phase conditions. The performance of the methods wa s enhanced by introducing postcolumn on-line photochemical derivatizat ion in combination with a diode-array detection. The column effluents were subjected on-line to UV irradiation (254 nm) and the characterist ic photo-induced spectral modifications were useful for the unambiguou s identification of the various analgesic compounds. The proposed HPLC methods were successfully applied to the analysis of commercially ava ilable analgesic dosage forms.