title: Sample stacking for the analysis of penicillins by microemulsion electrokinetic capillary chromatography.
abstract: We present a method for determining eight penicillin antibiotics using microemulsion electrokinetic chromatography (MEEKC). We studied how the composition of the microemulsion affected separation by modifying such parameters as the surfactant or the addition of organic solvents. The best microemulsion system consisted of 0.5% ethyl acetate, 1.2% 1-butanol, 2% Brij 35, 10% 2-butanol and 86.3% 10 mM borate buffer at pH 10. We studied the suitability of this microemulsion composition for analyzing a commercial drug. To improve the sensitivity of the method, we used the stacking technique reversed electrode polarity stacking mode (REPSM), which increased the detection limits by about 40-fold.
authors.affiliation: Department of Analytical Chemistry and Organic Chemistry, Rovira i Virgili University, Marcel lí Domingo s/n, E-43007 Tarragona, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Puig
authors.forename: Francesc
authors.initials: F
authors.lastname: Borrull
authors.forename: Carme
authors.initials: C
authors.lastname: Aguilar
authors.forename: Marta
authors.initials: M
authors.lastname: Calull
mesh_terms: D002021:Buffers; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D004655:Emulsions; D006863:Hydrogen-Ion Concentration; D010406:Penicillins / Q000032:analysis*; D012680:Sensitivity and Specificity; D012997:Solvents; D013501:Surface-Active Agents
chemical_list: D002021:Buffers; D004655:Emulsions; D010406:Penicillins; D012997:Solvents; D013501:Surface-Active Agents