Electrochemiluminescences (ECLs) based on tris(2,2'-bipyridine) ruthenium (II) [Ru(bpy)_3~(2+)] and some alkaloids or amines such as sophoridine, matrine, methamphetamine and amphatamine in phosphate buffer solution (pH 9.0) are studied. The light emission is mainly caused by the electro-oxidation reaction between amino group on the alkaloid compounds and Ru(bpy)_3~(2+) in a thin layer flow cell equipped with a glassy carbon disc electrode (22.1 mm~2) at about the potential of +1.30 V (vs. Ag/AgCl). The luminescence wavelength of 610 nm confirms that ECL is caused by Ru(bpy)_3~(2+*) back to its ground state. The effects of the nature and three-dimensional conformation of the substituents of these alkaloids on the ECL intensities are discussed. Ionization potentials and angle of C-N-C bond taken from calculation data further confirm the experimental results.

Key words: ELECTROLUMINESCENCE, CHEMILUMINESCENCE REACTION, BIPYRIDINE P, RUTHENIUM COMPOUNDS, ALKALOID