Potentiometric study of reaction between tetrabutylammonium periodate and phenothiazine in chloroform; application to the analysis of phenothiazine derivatives

The reaction between tetrabutylammonium periodate and phenothiazine in the presence of the strong acids in chloroform was studied by potentiometry and the reaction pathways were determined. The oxidimetric titration conditions of phenothiazine derivatives using a standardized chloroform solution of tetrabutylammonium periodate were optimized and a potentiometric detection of end points was utilized. The relative standard deviation for the determination of 5 mg phenothiazines was obtained about 1-1.5%. The method was applied for the determination of phenothiazines in various pharmaceutical preparations after extraction into chloroform. (C) 1997 Elsevier Science B.V.