Flow injection-chemiluminescence determination of cetirizine dihydrochloride in pharmaceuticals using tris(2,2'-bipyridyl)ruthenium (II)-Ag(III) complex reaction.

Abstract

A simple and sensitive flow injection-chemiluminescence (FI-CL) method was developed for determination of cetirizine dihydrochloride (CTZH) in pharmaceuticals. The method is primarily based on the enhancement effect of CTZH on the tris(2,2'-bipyridyl)ruthenium (II)-diperiodatoargentate (III) ([Ru(bpy)3 ]2+ -Ag(III) complex) CL system in an acidic medium. The optimum investigated variables of the CL reaction were: [Ru(bpy)3 ]2+ , 50 × 10-6 mol/L; sulfuric acid, 1.0 × 10-3 mol/L; Ag(III) complex, 100 × 10-6 mol/L; potassium hydroxide, 1.0 × 10-3 mol/L; flow rate, 3.0 ml/min and sample loop volume, 300 μl. The detection and quantification limits were 2.0 × 10-4 and 5.0 × 10-4 mg/L (S/N of 3 and 10) respectively with a linear calibration range of 5.0 × 10-4 to 7.5 mg/L (R2 = 0.9999, n = 11), injection throughput of 110/h and the relative standard deviations of 1.5-3.5% over the range studied. The methodology was successfully applied to determine CTZH in different pharmaceutical samples and validated with a high-performance liquid chromatography method, and resulted in the recovery of 94.6-108.6%. The probable CL reaction mechanism is described in brief.