Electrocatalytic Determination of Ascorbic Acid Using Glassy Carbon Modified with Nickel(II) Macrocycle Containing Dianionic Tetraazaannulene Ligand

L-Ascorbic acid (AsA) is known for its reductive properties and for its use on a wide scale as an antioxidant agent in foods and drinks; it is also important for therapeutic purposes and biological metabolism. Therefore, recent advances in the food and pharmaceutical industries and the need for nutritional assessments necessitate the development of a selective, simple and accurate method to determine AsA. Catalytic procedures are appreciated by analytical chemists for their sensitivity and simplicity in realization. Catalytic indicator reactions can be applied to the determination of a large number of compounds including the catalyst, inhibitors, activators, and compounds, which convert the catalyst into an active state (oxidizer, ligands), and catalytically inactive metal ions through the use of the competitive complexation principle. Due to its selectivity and sensitivity, an electrochemical method to determine AsA has been of considerable interest. A variety of examples of the electrochemical determination of AsA have been proposed. These include the glassy carbon electrode (GCE) and carbon paste electrode with complexes and organic compounds such as 1,5,8,12,Tetraaza-2,4,9,11-tetramethylcyclotetradecinatonickel(II), cobalt hexacyanoferrate , meso-tetrakis(o-nitrophenyl)tetrabenzoporphyrin with Fe(III), Ni(II), Mn(III) and ∗Corresponding author