title: Strategies for the on-line preconcentration and separation of hypolipidaemic drugs using micellar electrokinetic chromatography.
abstract: Three strategies were investigated for the simultaneous separation and on-line preconcentration of charged and neutral hypolipidaemic drugs in micellar electrokinetic chromatography (MEKC). A background electrolyte (BGE) consisting of 20 mM ammonium bicarbonate buffer (pH 8.50) and 50 mM sodium dodecyl sulfate (SDS) was used for the separation and on-line preconcentration of the drugs. The efficiencies of sweeping, analyte focusing by micelle collapse (AFMC), and simultaneous field-amplified sample stacking (FASS) and sweeping, were compared for the preconcentration of eight hypolipidaemic drugs in different conductivity sample matrices. When compared with a hydrodynamic injection (5 s at 50 mbar, 0.51% of capillary volume to detection window) of drug mixture prepared in the separation BGE, improvements of detection sensitivity of 60-, 83-, and 80-fold were obtained with sweeping, AFMC and simultaneous FASS and sweeping, respectively, giving limits of detection (LODs) of 50, 36, and 38 microg/L, respectively. The studied techniques showed suitability for focusing different types of analytes having different values of retention factor (k). This is the first report for the separation of different types of hypolipidaemic drugs by capillary electrophoresis (CE). The three methods were validated then applied for the analysis of target analytes in wastewater samples from Hobart city.
authors.affiliation: Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Dawod
authors.forename: Michael C
authors.initials: MC
authors.lastname: Breadmore
authors.forename: Rosanne M
authors.initials: RM
authors.lastname: Guijt
authors.forename: Paul R
authors.initials: PR
authors.lastname: Haddad
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D000960:Hypolipidemic Agents / Q000032:analysis*; D008958:Models, Molecular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry
chemical_list: D000960:Hypolipidemic Agents; D012967:Sodium Dodecyl Sulfate