Indirect atomic absorption spectrometric determination of pindolol, propranolol and levamisole hydrochlorides based on formation of ion associates with manganese thiocyanate and potassium ferricyanide

A new simple. accurate, precise and sensitive indirect method for the determination of pindolol HCl (1), propranolol HCl (1) and levamisole HCl (3) using atomic absorption spectrometry has been developed. The method is based on precipitation of the ion associates formed from the reaction of (1), (2) or (3) with manganese thiocyanate and,or potassium ferricyanide. Thr solubility of the solid complexes at the optimum conditions of pH and ionic strength values have been studied. Saturated solutions of each ion-associate were prepared under the optimum conditions and the metal ion content in the supernatant was determined. The method has been used for the determination of 1.14-17.07, 1.18-17.75 and 1.08-16.24 mu g/ml of (1), (2) and (3), respectively using manganese thiocyanate and 1.71-25.60, 1.77-26.62 and 1.62-24.36 mu g/ml of (1), (2) and (3), respectively using potassium ferricyanide. The method developed applied for analysis of bulk drugs and some of their pharmaceutical preparations. (C) 2000 Elsevier Science B.V. All rights reserved.