title: Use of folded micromachined pillar array column with low-dispersion turns for pressure-driven liquid chromatography.
abstract: In this study, we show for the first time that the separation efficiency of a pillar array column under pressure-driven liquid chromatography (LC) conditions can be improved using a separation channel with low-dispersion turns. The pillar array column was fabricated by reactive ion etching of a silicon substrate. With the low-dispersion-turn geometry, a column with a length and width of 110 mm and 400 microm, respectively, could be fabricated on a 20 x 20 mm microchip. Under nonretained conditions, the solute bands obtained for fluorescent compounds remained almost unchanged even after passing through the low-dispersion turns; however, significant skewing of the solute bands was observed in the case of constant-radius turns. Two coumarin dyes were well resolved under reversed-phase conditions, and a maximum theoretical plate number of 8000 was obtained. Successful separation of the fluorescent derivatives of six amino acids was achieved in 140 s. These results indicated that the separation efficiency of microchip chromatography could be significantly improved using a long separation channel with low-dispersion turns.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Aoyama
authors.forename: Akira
authors.initials: A
authors.lastname: Saeki
authors.forename: Masao
authors.initials: M
authors.lastname: Noguchi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Shirasaki
authors.forename: Shuichi
authors.initials: S
authors.lastname: Shoji
authors.forename: Takashi
authors.initials: T
authors.lastname: Funatsu
authors.forename: Jun
authors.initials: J
authors.lastname: Mizuno
authors.forename: Makoto
authors.initials: M
authors.lastname: Tsunoda
mesh_terms: D002853:Chromatography, Liquid / Q000295:instrumentation*; D003374:Coumarins / Q000302:isolation & purification; D005456:Fluorescent Dyes / Q000302:isolation & purification; D007267:Injections; D046228:Microarray Analysis; D011312:Pressure
chemical_list: D003374:Coumarins; D005456:Fluorescent Dyes; C030123:coumarin