title: High-sensitivity analysis of anionic sulfonamides by capillary electrophoresis using a synergistic stacking approach.
abstract: A synergistic stacking approach whereby field-enhanced sample injection and micelle-to-solvent stacking in capillary zone electrophoresis are combined has been developed and has been applied to the separation and quantification of anionic sulfonamides. Electrokinetic injection of the sample in a low conductivity alkaline diluent was performed for 90s at -15kV. Micelle-to-solvent stacking was then undertaken by hydrodynamic injection of micellar cetyltrimethylammonium bromide solution prior to the electrokinetic injection of sample that also contained 50% methanol. This combined stacking approach, when compared to a typical hydrostatic injection, provided improvements in peak height and corrected peak area in the range of 397-1024 and 758-1246, respectively. Limits of quantification in the range of 0.01-0.03μg/mL were obtained for sulfamerazine, sulfamethazine and sulfamethizole and were sufficient for the determination of these analytes in river water. The percentage recovery and accuracy values obtained for a fortified river water sample that had been subjected to sample preparation by evaporation and reconstitution with diluent were 74-135%. Intra-day and inter-day repeatabilities for migration time, peak height, and corrected peak area were in the range 0.5-5.0% (percentage relative standard deviation, n=8) and these relatively low values were attributed to the use of a stable capillary coating established by the successive multiple ionic-polymer layer technique.
authors.affiliation: Australian Centre for Research on Separation Science, School of Physical Sciences-Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia.
authors.forename: Ria Marni
authors.initials: RM
authors.lastname: Tubaon
authors.affiliation: Australian Centre for Research on Separation Science, School of Physical Sciences-Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Haddad
authors.affiliation: Australian Centre for Research on Separation Science, School of Physical Sciences-Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia. Electronic address: jquirino@utas.edu.au.
authors.forename: Joselito P
authors.initials: JP
authors.lastname: Quirino
mesh_terms: D000838:Anions / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000592:standards*; D004784:Environmental Monitoring / Q000295:instrumentation*; D057230:Limit of Detection; D045483:Rivers / Q000737:chemistry; D012997:Solvents; D013449:Sulfonamides / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000838:Anions; D012997:Solvents; D013449:Sulfonamides; D014874:Water Pollutants, Chemical
keywords: Capillary zone electrophoresis; Field-enhanced sample injection; Micelle-to-solvent stacking; River water; Successive multiple ionic-polymer layer; Sulfonamides