Determination of sulfadiazine and sulfamethoxazole by capillary electrophoresis with end-column electrochemical detection

Abstract

Capillary electrophoresis (CE) with end-column electrochemical detection (EC) of sulfadiazine (SDZ) and sulfamethoxazole (SMZ) is described. Under the optimum conditions, SDZ and SMZ were separated satisfactorily, and a highly sensitive and stable response was obtained at a potential of 1.1 V versus Ag/AgCl. Optimized end-column detection provides detection limits as low as 0.1 microM for both compounds, which corresponds to 0.024 and 0.021 fmol with peak efficiencies of 394,000 and 335,000 theoretical plates for SDZ and SMZ, respectively. The calibration graph was linear over three order of magnitude. The relative standard deviations (n = 12) of peak currents and migration times were 2.3 and 2.7%, and 0.8 and 1.3%, respectively, for the two compounds. The proposed method was applied to the analysis of tablets and human urine samples with satisfactory results.

Simultaneous Differential Pulse Voltammetric Determination of Sulfamethoxazole and Trimethoprim on a Boron‐Doped Diamond Electrode

“…There are only a few reports available on the electrochemical detection of sulfa drugs [16 -24], and in some of them the oxidation/reduction products can be adsorbed strongly on the surface of the electrodes, which thus tend to become fouled and deactivated [16 -18]. For example, You et al [17] observed a rapid decrease in the current response at carbon fiber electrodes during the detection of sulfadiazine and sulfamethoxazole after separating them by capillary electrophoresis; they then pretreated the electrode by potential cycling to regain the response. On the other hand, Preechaworapun et al [24], using a boron-doped diamond electrode (BDD), found no deactivation during the electrochemical detection of other sulfonamides (including sulfadiazine), after separating them by HPLC.…”

Electroanalytical determination of sulfadiazine and sulfamethoxazole in pharmaceuticals using a boron-doped diamond electrode

“…Owing to concern over the analytical determination of sulfa drugs in pharmaceuticals and residues in food products, various methods have been proposed, including high-performance liquid chromatography (HPLC) [3][4][5][6][7][8][9][10], capillary electrophoresis [11][12][13], and gas chromatography [14][15][16]. These methods have proven to be sensitive and suitable for sulfonamide determination.…”

Applications of Microelectrodes in Capillary Electrophoresis/Electrochemical Detection

“…Under the optimum condition, a low detection limit of 0.1 mM, 0.1 mM was obtained with peak ef®ciencies of 394 000 and 335 000 theoretical plates for SDZ and SMZ, respectively. This method was applied into real sample determination of SDZ and SMZ [102].…”