Sol-gel-immobilized Tris(2,2′-bipyridyl)ruthenium(II) electrogenerated chemiluminescence sensor for high-performance liquid chromatography

The sol-gel-immobilized Tris(2,2′-bipyridyl)ruthenium(II) [Ru(bpy)32+] electrogenerated chemiluminescence (ECL) sensor was applied to the reversed-phase high-performance liquid chromatography (HPLC) determination of phenothiazine derivatives (promazine, chlorpromazine, triflupromazine, thioridazine, and trifluoperazine) and erythromycin in human urine samples. In this method, Ru(bpy)32+ was immobilized in sol-gel-derived titania (TiO2)-Nafion nanocomposite films coated on a dual platinum electrode. This method eliminates an extra pump needed for the delivery of Ru(bpy)32+ reagent into a reaction/observation zone in front of photomultiplier tube because the immobilized-Ru(bpy)32+ is recycled on the electrode surface by an applied potential at +1.3 V versus Ag/AgCl (3 M NaCl) reference electrode. The resulting analytical performances such as detection limit, working range, sensitivity, and measurement precision were slightly worse than those obtained with the conventional post-column Ru(bpy)32+ addition approach. The lack of significant interferences and the low detection limits for phenothiazine derivatives and erythromycin indicate that the proposed HPLC-Ru(bpy)32+ ECL detection method is suitable for the determination of those compounds in biological fluids.