Sensitivity Improvement of the Oxidation of Tetracycline at Acetylene Black Electrode in the Presence of Sodium Dodecyl Sulfate

The oxidation of tetracycline (TC) was investigated at an acetylene black electrode in the presence of sodium dodecyl sulfate (SDS). TC exhibited a sensitive oxidation peak in the medium system, which was attributed to the enhanced adsorption of protonated TC at the negatively charged SDS film on the electrode surface. The mechanism of the electrode process was discussed, and some experimental conditions were optimized. The oxidation peak current was proportional to TC concentration in the range of 1.2×10−7–6.0×10−5 M, and based on three times the background signal, a detection limit of 1.2×10−8 M was obtained for 150 s accumulations. The method has been used to determine TC in honey and pharmaceutical, and the results compared favorably.