Abstract
A new carbon paste electrode modified by Ni(II) complex was prepared for the electrochemical removal of nitrate from drinking water. The tripod S2N ligand, namely Hydro{bis(2-isopropylphenyl-2-thioimidazol- 1-yl)(5-phenyl-3-methyl-pyrazol-1-yl)}borate: L, and its mononuclear Ni(II) complex [LNi-NO3] were prepared and characterized in the solid state by infrared (FT-IR), and thermal analysis (TA) and in solution by conductivity, and H-1 NMR. The carbon paste modified electrode was prepared by immobilization Ni(II) complex in carbon paste. The carbon paste modified electrode was characterized by scanning electronic microscopy (SEM) and cyclic voltammetry (CV). The carbon paste modified electrode showed only one oxidation peak in the anodic scan due to the oxidation of Ni(II) to Ni(III). By the addition of nitrate ions no reduction peaks was observed, while the oxidation peak height for Ni(II) complex was decreased. The decrease in the oxidation peak current for Ni(II) complex due a part Ni(II) complex used in the reduction of nitrate to nitrite ions. The prepared electrode was applied for the electrochemical removal of nitrate form different drinking water samples