Determination of Chloramphenicol by a New Electrochemically Activated Glassy Carbon Electrode in Sodium Sulfate Medium

In this paper, a two-step method combining potentiometry and cyclic voltammetry (CV) was used to prepare the activated glassy carbon electrode (GCE), and a new and simple analytical method for the determination of chloramphenicol (CAP) by using the activated GCE in the new activation medium of 0.1 mol l −1 Na 2 SO 4 was established. The optimum activation conditions were as follows: polarized at 1.75 V (vs SCE) for 320 s and scanned for 10 cycles in the potential ranging from −1.2 V to 1.0 V with CV at 150 mV s −1 . Afterward, the electrochemically Na 2 SO 4 medium activated GCE (SSA-GCE) was prepared. The reduction peak current of CAP at −0.64 V (vs SCE) was 13.11 times higher than that of bare GCE under the optimal analytical conditions. The prepared SSA-GCE showed fast surface electron transfer rate, high repeatability, good stability with linear ranges of 0.2 to 2 μ mol l −1 and 2 to 50 μ mol l −1 , and detection limit (S/N = 3) of 0.017 μ mol l −1 . The SSA-GCE was applied in the detection of CAP in aquaculture water. The recovery was between 95.0% and 103.6%, indicating that SSA-GCE was suitable for the determination of CAP in aquaculture water, and the mechanism of electrode reaction was discussed.