Disposable thick film modified graphite electrodes for stripping voltammetry

Disposable thick film modified graphite electrodes (DTFMGE) are described. Disposable thick film graphite electrodes (DTFGE) are used as a substrate for DTFMGEs. Insoluble inorganic mercury salt, organic insoluble complexes or soluble compounds protected with Nafion were used to modify electrode surface. That provides the possibility to determine Pb, Cd, Cu ions concentration without using metallic mercury and its soluble salts and to eliminate the need for mechanical surface regeneration. As to their characteristics, these electrodes differ little from the usual ones which are coated with mercury either beforehand or in situ. Test concentrations of Me2+ were: 1 mu g l(-1) Cd(II) + 2.0 mu g l(-1) Pb(II) + 5 mu g l(-1) Cu(II) in one series of the experiments, 2 mu g l(-1) Cd(II) + 4.0 mu g l(-1) Pb(II) in the second series and 10 mu g l(-1) Cd(II) + 10 mu g l(-1) Pb + 10 mu g l(-1) Cu(II) in the third series. Two additions were injected into electrochemical cell. The detection limit for the elements mentioned is on the sub-mu g l(-1) level. Relative standard deviation is 2-5%. 0.1, 0.2 and 1 M HCl were used as background electrolytes. Results were obtained without deaeration of the solution. Well shaped peaks, stable peak increments after standard additions introduction and satisfactory correlation between added and found concentrations of metal ions during a long period of time makes the electrodes promising prospective for stripping voltammetry.