1995 Volume 11 Issue 5 Pages 749-754
The electrochemiluminescence of tris(2, 2′-bipyridine)ruthenium(II) [Ru(bpy)32+] was applied to high-performance liquid chromatographic determination of ascorbic acid. Ascorbic acid was separated by a C18 reversed-phase column with a mobile phase containing 15mM NaH2PO4-K2HPO4 (pH 6.5). The eluted ascorbic acid was mixed with 0.5mM Ru(bpy)32+ within the flow tube. The solution then passed through a thin layer flow cell equipped with a glassy carbon electrode and both ascorbic acid and Ru(bpy)32+ were oxidized at +1.5V (vs. Ag/AgCl). The reaction of electrolytically formed Ru(bpy)33+ with oxidized ascorbic acid emitted light. The detection limit was 10pmol for ascorbic acid at an S/N ratio of 3, and the linear calibration range was 0.06-80nmol. The method was successfully applied to determination of ascorbic acid in soft drinks and apple juice.
