Abstract: A new electrochemiluminescence flow injection analysis system was studied for anal. for some amino acids, peptides and nitrogen compounds by using tris(2,2'-bipyridine)ruthenium(II) [Ru(bpy)32+]. The luminescence of Ru(bpy)32+, which was oxidized to Ru(bpy)33+ on the surface of glassy carbon electrode at +1.35 V (vs. Ag/AgCl) would be intensified with the injection of amino acid peptide or nitrogen compound The detection limits of the amino aids by this method ranged from 0.1 pmol of hydroxyproline and proline to 0.4 nmol of serine. Voltammetric anal. revealed the oxidation of Ru(bpy)32+ to Ru(bpy)33+ was nearly reversible and the light emission was caused by the excited state of Ru(bpy)32+. A reaction mechanism is proposed.

Abstract: Sample solution was injected into borate buffer (pH 8.7) and chloramine T in 2-methoxyethanol and, following oxidation, the sample was decarboxylated in a mixing coil in a boiling-water bath. The resulting solution, containing pyrrole, was mixed (1:1) with Ehrlich reagent and a colored product was formed in a reaction coil. The absorbance of the solution was measured at 560 nm. The calibration graph was rectilinear for up to 100 µg mL-1 of hydroxyproline. The coefficient of variation (n = 24) was 1.1% at 100 µg mL-1.