title: Online preconcentration using monoliths in electrochromatography capillary format and microchips.
abstract: Online preconcentration and separation of analytes using an in situ photopolymerized hexyl acrylate-based monolith stationary phase was evaluated using electrochromatography in capillary format and microchip. The band broadening occurring during the preconcentration process by frontal electrochromatography and during the desorption process by elution electrochromatography was studied. The hexyl acrylate-based monolith provides high retention for neutral analytes allowing the handling of large sample volumes and its structure allows rapid mass transfer, thus reducing the band broadening. For moderately polar analytes such as mono-chlorophenols that are slightly retained in water, it was shown that enrichment factors up to 3500 can be obtained by a hydrodynamic injection of several bed volumes for 120 min under 0.8 MPa with a decrease in efficiency of 50% and a decrease of 30% for the resolution between 2- and 3-chlorophenol. An 8 min preconcentration time allows enrichment factors above 100 for polyaromatic hydrocarbons. The interest of these monoliths when synthesized in microchip is also demonstrated. A 200-fold enrichment was easily obtained for PAHs with only 1 min as preconcentration time, without decrease in efficiency.
authors.affiliation: Laboratoire Environnement et Chimie Analytique, UMR CNRS 7121, ESPCI, Paris, France.
authors.forename: Violaine
authors.initials: V
authors.lastname: Augustin
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Proczek
authors.forename: José
authors.initials: J
authors.lastname: Dugay
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Descroix
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Hennion
mesh_terms: D000179:Acrylates / Q000138:chemical synthesis / Q000737:chemistry*; D053801:Capillary Electrochromatography / Q000295:instrumentation* / Q000379:methods*; D056656:Lab-On-A-Chip Devices; D046208:Microchip Analytical Procedures / Q000379:methods*; D010636:Phenols / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000179:Acrylates; D010636:Phenols; D011084:Polycyclic Aromatic Hydrocarbons; C526535:hexyl acrylate