Simultaneous determination of amiodarone and its metabolite desethylamiodarone by high-performance liquid chromatography with chemiluminescent detection.

A novel method was developed for the determination of amiodarone and desethylamiodarone by high-performance liquid chromatography (HPLC) coupled with chemiluminescent (CL) detection. The procedure is based on the post-column photolysis of the analytes into photoproducts which are active in the tris(2,2'-bipyridyl)ruthenium(III) [Ru(bpy)(3)(3+)] CL system. Ru(bpy)(3)(3+) was on-line generated by photo-oxidation of the Ru(II) complex in the presence of peroxydisulfate. The separation was carried out on a Mediterranea C(18) column with isocratic elution using a mixture of methanol and 0.017 mol L(-1) ammonium sulfate buffer of pH 6.8. Under the optimum conditions, analytical curves, based on standard solutions, were linear over the range 0.1-50 microg mL(-1) for amiodarone and 0.5-25 microg mL(-1) for desethylamiodarone. The detection limits of amiodarone and desethylamiodarone were 0.02 and 0.11 microg mL(-1), respectively. Intra- and inter-day precision values of 0.9% relative standard deviation (R.S.D.) (n=10) and 1.6% R.S.D. (n=15), respectively, were obtained. The method was applied successfully to the determination of these compounds in serum and pharmaceutical formulations.