title: C18 silica packed capillary columns with monolithic frits prepared with UV light emitting diode: usefulness in nano-liquid chromatography and capillary electrochromatography.
abstract: In this paper the potential of fused silica capillaries packed with RP18 silica particles entrapped with monolithic frits using both nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) was investigated. Frits were prepared after removing a short part of the polyimide layer on the capillary wall and irradiating the polymerization mixture with an UV-light emitter diode (LED) at 370 nm. The capillary, was rotated during the polymerization procedure in order to obtain a homogeneous monolith. The distance of the LED from the capillary and the exposure time to UV light were studied in order to obtain frits with good porosity and high robustness. A mixture containing five alkylbenzenes was selected as sample and analyzed by both nano-LC and CEC. The standard mixture was baseline separated with good efficiency in the range 78,000-93,000 and 99,000-113,000 plates/m in nano-LC and CEC, respectively. The columns resulted to be very robust and the prepared monolithic frits allowed working with backpressure as high as 400 bar (nano-LC). In addition high voltages were applied in CEC (25-30 kV) without bubbles formation in absence of pressure assistance during runs.
authors.affiliation: Institute of Chemical Methodologies, Consiglio Nazionale delle Ricerche, Area della Ricerca di Roma I, Via Salaria Km 29,300 - 00015 Monterotondo (Rome), Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: D'Orazio
authors.forename: Salvatore
authors.initials: S
authors.lastname: Fanali
mesh_terms: D001555:Benzene Derivatives / Q000302:isolation & purification; D053801:Capillary Electrochromatography / Q000295:instrumentation* / Q000379:methods; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D011312:Pressure; D012822:Silicon Dioxide / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D001555:Benzene Derivatives; D012822:Silicon Dioxide