title: Capillary electrophoresis of some tetracycline antibiotics coupled with reductive fast cyclic voltammetric detection.
abstract: The separation and quantitative performance parameters for tetracycline, chlortetracycline and oxytetracycline antibiotics were investigated by capillary zone electrophoresis coupled with fast cyclic voltammetric detection. Optimization of pH and complexation with a boric acid-sodium tetraborate buffer provided good resolution of all compounds. Detection by electrochemical reduction using fast on-line cyclic voltammetric detection with a Hg-film-microm electrode gave detection limits (2 x peak-to-peak baseline noise) of 7 x 10(-7) mol/l for tetracycline and chlortetracycline, and 1.5 x 10(-6) mol/l for oxytetracycline. The influence of electrode material, potential range and scan rate was examined and discussed. Optimal electrochemical detection was obtained at a Hg-film electrode with a waveform that consisted of an initial constant potential of -0.6 V for 200 ms followed by a cyclic voltammetry (CV) scan at 300 V/s from - 0.6 V to a vertex potential of 1.7 V. The analytical signal was obtained by plotting the integrated values of the CV current from each applied waveform as a function of time. The calibration plot (peak areas) for each separated peak was found to be linear over three-orders of magnitude.
authors.affiliation: Chemistry Department, University of Saskatchewan, Saskatoon, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Zhou
authors.forename: G C
authors.initials: GC
authors.lastname: Gerhardt
authors.forename: A
authors.initials: A
authors.lastname: Baranski
authors.forename: R
authors.initials: R
authors.lastname: Cassidy
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000302:isolation & purification*; D002751:Chlortetracycline / Q000032:analysis / Q000302:isolation & purification; D004563:Electrochemistry; D019075:Electrophoresis, Capillary; D010118:Oxytetracycline / Q000032:analysis / Q000302:isolation & purification; D013752:Tetracycline / Q000032:analysis / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D013752:Tetracycline; D002751:Chlortetracycline; D010118:Oxytetracycline