STRIPPING VOLTAMMETRY WITH ADSORPTION ACCUMULATION FOR TRACE DETERMINATION OF SOME THIOGUANINE DERIVATIVES

Controlled adsorptive accumulation of 6-thioguanine (6TG), 6-thioguano sine (6TGS) and 8-thioguanosine (8TGS) on the hanging mercury drop ele ctrode (HMDE) provides the basis for the direct stripping measurement of these compounds in the nmol concentration level. The method also ha s been developed for trace determination of these biological compounds in the presence of copper, due to the strong accumulation of the Cu(I I)-thiol complex at the surface of the HMDE. The adsorption and redox behaviour are explored by cyclic voltammetry. Experimental and instrum ental parameters for the quantitative analysis are optimized. The limi ts of detection are given in absence and presence of Cu(II). A statist ical analysis of the calibration curve data is included.