Electrochemical Behavior and Electrochemical Determination of Tiamulin Fumarate at an Ionic Liquid Modified Carbon Paste Electrode

The electrochemical behavior of tiamulin fumarate (TF) at ionic liquid N-Butylpyridinium hexafluorophosphate (BPPF6) modified carbon paste electrode (BPPF6/CPE) was investigated and further used for tiamulin fumarate sample determination. BPPF6/CPE showed an enhanced electrochemical response towards the electrochemical oxidation of TF. A well-defined and sensitive oxidation peak was observed at BPPF6/CPE in 0.10 M phosphate buffer solution (PBS, pH = 6.80). The oxidation peak current of TF increased significantly at BPPF6/CPE compared with that at carbon paste electrode and the BPPF6/CPE was characterized by the electrochemical impedance spectroscopy (EIS). At the same time, the electrochemical kinetics parameters of TF on the BPPF6/CPE were evaluated. Under the optimized conditions, the oxidation peak currents were linearly dependent on the concentration of TF in the range of 0.3-9.0 mu M and 9.0-0.3 mM, with a detection limit of 0.16 mu M (S/N = 3). The proposed method has been successfully applied in the electrochemical quantitative determination of TF content in commercial injection samples.