SIMULTANEOUS DETERMINATION OF PURINE-BASES, RIBONUCLEOSIDES AND RIBONUCLEOTIDES BY CAPILLARY ELECTROPHORESIS ELECTROCHEMISTRY WITH A COPPERELECTRODE

Simultaneous determination of purine bases, ribonucleosides and ribonu cleotides was achieved by coupling capillary electrophoresis (CE) with wall-jet amperometric detection. A 200 mu m diameter copper disk elec trode was applied at working potential, +0.65 V vs. saturated calomel electrode. The current response of high sensitivity and stability was obtained in strong basic solutions which were suitable for satisfactor y CE separations. The calibration curve was linear over 2-3 orders of magnitude and the limits of detection for adenine, guanine, xanthine, uric acid, adenosine, guanosine, adenosine-5'monophosphate and guanosi ne-5'-monophosphate were below 9 fmol (S/N=3). The use of this method for the separation and detection of compounds present in human plasma samples was reported.