title: Integrated microdevice for preconcentration and separation of a wide variety of compounds by electrochromatography.
abstract: An integrated microdevice was developed to couple on-chip SPE to separation by channel electrochromatography. An acrylate-based monolith was synthesized within a glass microdevice by photoinitiated polymerization. It was used for both separation and preconcentration by direct injection on the head of the stationary phase or by confining the preconcentration step in a given zone of the stationary phase. The composition of the polymerization mixture was chosen to achieve a monolithic material containing both hydrophobic and charged moieties to ensure an electroosmotic flow for separation. As a consequence the extraction procedure occurs via hydrophobic and ionic interactions. Neutral, ionizable and charged compounds were successfully preconcentrated and separated within the microdevice through electrochromatographic mechanisms, highlighting the versatility of this device. The performance of the integrated microdevice was demonstrated with the preconcentration and separation of a mixture of PAHs for which a signal enhancement factor (SEF) of 270 was achieved within 120 s of preconcentration. In the case of charged and ionizable compounds, according to the electrolyte composition, contributions of both reverse-phase and ion-exchange mechanisms were used to perform effective electrochromatographic preconcentration. A SEF of 250 was obtained for the model-charged compound within 20 s of preconcentration. Finally, the potentials of on-chip preconcentrate and separate both neutral and ionized compounds have been demonstrated using a mixture of model compounds.
authors.affiliation: Laboratoire Environnement et Chimie Analytique, UMR CNRS 7121, Paris, France.
authors.forename: Gaelle
authors.initials: G
authors.lastname: Proczek
authors.forename: Violaine
authors.initials: V
authors.lastname: Augustin
authors.forename: Stephanie
authors.initials: S
authors.lastname: Descroix
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Hennion
mesh_terms: D002845:Chromatography / Q000295:instrumentation / Q000379:methods; D007474:Ion Exchange; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons