Determination of tetracycline by adsorptive differential pulse cathodic stripping voltammetry

A novel type of Pb-polyaminophenol filmed glassy carbon electrode for adsorptive cathodic stripping analysis of trace amounts of tetracycline was developed. The Pb-polymer electrode was fabricated in situ by simultaneous electrodeposition of Pb and cathodic electropolymerization of 4-nitrophenol in a sodium acetate medium at -1.5 volt.The outputs of some experiments showed that tetracycline can be adsorbed on the surface of this Pb-polymer filmed electrode in an open circuit condition. Therefore it was used in adsorptive cathodic stripping analysis of tetracycline. Among new kinds of environmental contaminants, tetracyclines (TCs) are referred to as modern pollutants, since they have been found in soil and aquatic media [1].These compounds are routinely used for human therapy and in the livestock industry [2]. The response of the electrode was enhanced in the presence of cetyltrimethylammonium bromide. Some parameters affecting the performance of the electrode were studied and optimized. The response of the electrode was linear in the range of 5×10-8 - 1×10-5 mol L-1 of tetracycline with a correlation coefficient of 0.9981. The relative standard deviation for 5×10-7 mol L-1 of tetracycline was 1.8 % (n=5). The L.O.D and L.O.Q were 4×10-9 and 1.3×10-8 mol L-1 of tetracycline, respectively. The introduced electrode was used for determination of tetracycline residues in some samples and the obtained results were in good agreement with the results of HPLC