Chelatometric Determination of Pharmaceuticals. VII. : Determination of Organic Bases using Reinecke Salt

Abstract

Diphenehydramine hydrochloride, chlorphenylamine maleate, thonzylamine hydrochloride, promazine hydrochloride, procaine hydrochloride, papaverine hydrochloride, quinine hydrochloride, and atropine sulfate were precipitated with Reinecke salt. Chromium (III) in the precipitation was determined by chelatometry. When 3-15 mg of the base was treated, the error was less than ±0.5%. The recommended procedure is as follows : Ten mililiter of the sample solution, 5 ml of 20% sulfuric acid, and 5 ml of 1% Reinecke salt solution are mixed. After standing for 1 hour, the precipitate is filtered on a glass filter, washed with cold water, and dissolved in small portion of dimethylformamide. The solution is mixed with 5-10 ml of 0.01M EDTA solution and acetate buffer (pH 4), after boiling 10 minutes, titrated fluoro-photometrically with 0.01M copper sulfate solution using calcein as the indicator. Determination of the organic bases in powder was discussed.