Reversed flow-injection method for estimation of chlorpromazine in pharmaceuticals and urine samples using charge-transfer complexation

Abstract

A simple, automated and sensitive reversed flow-injection analysis (rFIA) method for the determination of chlorpromazine hydrochloride (CLP) in pharmaceutical formulations and human urine samples is described. The automated method is based on the formation of charge-transfer complex between CLP (donor) with new reagent (an acceptor) used for the first time namely, 4,4’-tetramethyl-diaminodiphenylmethane (TDM) in the presence of K 2 S 2 O 8 as an oxidant. An intense blue-colored product, which gave a maximum absorbance at 604 nm, was formed immediately at room temperature. The various chemical and physical conditions that affected the reaction have been studied. The calibration curve was rectilinear within the concentration range 1-45 µg/mL and the detection and quantification limits of 0.72 and 2.40 µg/mL respectively with a sample through put of 80 sample/hour. The proposed procedure was applied successfully for the estimation of CLP and the results obtained were favorably compared with those given by a reference method, and there was no significant difference between the obtained results, regarding accuracy and precision at the 95% confidence level.