ANODIC-STRIPPING POTENTIOMETRIC DETERMINATION OF ANTIMONY ON A COMBINED ELECTRODE

The anodic stripping potentiometric (ASP) determination of antimony on -a combined working-auxiliary-reference electrode system is described. The method utilises 3 M HCl as supporting electrolyte and a combined glassy carbon mercury film electrode at an electrolysis potential of - 400 mV versus Ag-AgCl (1 M HCl) for the reliable determination of ultr atrace concentrations of antimony. A detection limit of 0.3 mu g l(-1) and a linear concentration range of 0.3-150 mu g/l(-1) antimony were accomplished under these Conditions with an electrolysis time of 10 mi n. The use of L-cysteine was effective for the reduction of Sb-v to Sb -III and its subsequent use for-the ASP determination of the metalloid . The method was successfully applied to the determination of trace an d ultratrace concentrations of antimony in water and orchard leaves sa mples.