Simultaneous determination of purine bases, ribonucleosides and ribonucleotides by capillary electrophoresis-electrochemistry with a copper electrode

Simultaneous determination of purine bases, ribonucleosides and ribonucleotides was achieved by coupling capillary electrophoresis (CE) with wall-jet amperometric detection. A 200 μm diameter copper disk electrode 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 satisfactory 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 guanosine-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.