DISPOSABLE THICK-FILM MODIFIED GRAPHITE-ELECTRODES FOR STRIPPING VOLTAMMETRY

Disposable thick film modified graphite electrodes (DTFMGE) are descri bed. Disposable thick film graphite electrodes (DTFGE) are used as a s ubstrate for DTFMGEs. Insoluble inorganic mercury salt, organic insolu ble complexes or soluble compounds protected with Nafion were used to modify electrode surface. That provides the possibility to determine P b, Cd, Cu ions concentration without using metallic mercury and its so luble salts and to eliminate the need for mechanical surface regenerat ion. As to their characteristics, these electrodes differ little from the usual ones which are coated with mercury either beforehand or in s itu. 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 th ird series. Two additions were injected into electrochemical cell. The detection limit for the elements mentioned is on the sub-mu g l(-1) l evel. Relative standard deviation is 2-5%. 0.1, 0.2 and 1 M HCl were u sed as background electrolytes. Results were obtained without deaerati on of the solution. Well shaped peaks, stable peak increments after st andard additions introduction and satisfactory correlation between add ed and found concentrations of metal ions during a long period of time makes the electrodes promising prospective for stripping voltammetry.