Chronoamperometric Detection of Amoxicillin at Graphite Electrode using Chelate Effect of Copper(II) Ions : Application in Human Blood and Pharmaceutical Tablets

Abstract

A novel electrochemical method is suggested for indirect chronoamperometric determination of amoxicillin (AMX) in the presence of copper ions Cu (II) at carbon paste electrode (CPE). The method is based on the interaction between the β-lactam antibiotic and copper ions. This interaction was firstly studied by square wave voltammetry (SWV), where the peak corresponding to the oxidation of AMX at 0.7 V decreases significantly in the presence of copper ions. The reaction product is characterized by UV-visible spectrophotometry and Infrared spectroscopy (IR). Moreover, when AMX was added to supporting electrolyte containing copper ions, the chronoamperomet-ric current of the Cu(II)/Cu(I) redox system was increased. Hence, this increase in the current was used for indirect determination of amoxicillin. By selecting an appropriate concentration of copper (II), the calibration curve for AMX was established in the concentration range of 1.95 × 10 À 7 to 1.46 × 10 À 5 mol L À 1 . The detection limit was found to be 8.84 × 10 À 8 mol L À 1 . The influence of different organic compounds on the AMX determination and the effect of coexisting of other metal ions in the electrolytic solution were studied. The applicability of the proposed method was tested in human blood and pharmaceutical tablets.

Electrochemical Investigation of Amoxicillin Interaction with Some Metal Ions Related to Complexation Process

“…It presents an oxidation peak at 0.8 V attributed to the oxidation of OH group of the phenolic sites of AMX (φ-OH). 30 The mechanism of the electrochemical oxidation of AMX is 22 :…”

“…[15][16][17][18][19][20][21] In our previous work, we reported that the electrochemical behavior of AMX is influenced by the presence of certain metal ions. 22 This motivated us to conduct an in-depth study to elucidate the effect of metal ions such as Cu(II), Zn(II), Fe(III) on the electrochemical behavior of AMX.…”