title: Different strategies for the preconcentration and separation of parabens by capillary electrophoresis.
abstract: Several strategies, namely, large volume sample stacking (LVSS), field-amplified sample injection (FASI), sweeping, and in-line SPE-CE, were investigated for the simultaneous separation and preconcentration of a group of parabens. A BGE consisting of 20 mM sodium dihydrogenphosphate (pH 2.28) and 150 mM SDS with 15% ACN was used for the separation and preconcentration of the compounds by sweeping, and a BGE consisting of 30 mM sodium borate (pH 9.5) was used for the separation and preconcentration of the compounds by LVSS, FASI, and in-line SPE-CE. Several factors affecting the preconcentration process were investigated in order to obtain the maximum enhancement of sensitivity. The LODs obtained for parabens were in the range of 18-27, 3-4, 2, and 0.01-0.02 ng/mL, and the sensitivity evaluated in terms of LODs was improved up to 29-, 77-, 120-, and 18,400-fold for sweeping, LVSS, FASI, and in-line SPE-CE, respectively. These preconcentration techniques showed potential as good strategies for focusing parabens. The four methods were validated with standard samples to show the potential of these techniques for future applications in real samples, such as biological and environmental samples.
authors.affiliation: Department of Analytical Chemistry and Organic Chemistry, Faculty of Chemistry, Rovira i Virgili University, Tarragona, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Maijó
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: D000096:Acetone / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D016014:Linear Models; D000432:Methanol / Q000737:chemistry; D010226:Parabens / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D010756:Phosphoric Acids / Q000737:chemistry; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D000097:Acetonitriles; D010226:Parabens; D010756:Phosphoric Acids; D000096:Acetone; C030242:phosphoric acid; D000432:Methanol; C032159:acetonitrile