Sonoelectrochemical studies of guanine and guanosine l

The voltammetric behaviour of the purine base guanine and the corresponding n,.,c!eoside guanosine at a glaxgy carbon ek~rode was investigated with the help of ultrasound. The adsorption of guanine and guanosiae as well as the adsorption of tJieir ox~Kion pf~:gh~ affects the overall voltammetric characteristics dramatically. In particular, the effect of ultrasound on the simultaneous adsoq~aa of guanine and guanosine was studied in detail. Quantitative sonovdtammetric experiments show the number of electrons invdved ia the electro-oxidation of guanosine to be two. Sonovoltammetry, i.e. the combination of voltammetry arid ultrasonic irrad~t/on, is demonstrated to be a useful approach to control the extent of adsorption of tie relevant species and to avoid electrode fouling. T~s alkrws the development of reliable analytical pr~edures for the determination of guanine and guanosine, which are described in deudL © 1997 Elsevier Science S.A.