Determination of Chlorpromazine Hydrochloride and Promethazine Hydrochloride by Resonance Rayleigh Scattering Method Coupled with Flow Injection Technique
In HCl medium with pH 1.0,12-tungstophosphori acid (TP) reacted with chlorpromazine hydrochloride (CPZ) or promethazine hydrochloride (PMZ) to form ion-association complexes,respectively,which resulted in significant enhancement of the resonance Rayleigh scattering (RRS) intensity.The maximum peaks were located at 359 nm (TP-CPZ) and 346 nm (TP-PMZ).In a certain range,the RRS intensity was proportional to the concentration of CPZ or PMZ.Based on it,a flow injection analysis (FIA) coupled to resonance Rayleigh scattering (RRS) method was developed for the determination of CPZ and PMZ.The detection limits (3σ) were 1.7 μg/L for CPZ and 3.0 μg/L for PMZ.The reaction conditions and FIA parameters for the systems were optimized.Take TP-CPZ system with high sensitivity as an example,the effect of coexisting substances was investigated,which showed that the method had good selectivity.The proposed method was used for the determination of CPZ in the pharmaceutical formulation and in pig liver with satisfactory results.