Use of Folded Micromachined Pillar Array Column with Low-Dispersion Turns for Pressure-Driven Liquid Chromatography

摘要

In this study, we show for the first time that the separationnefficiency of a pillar array column under pressure-drivennliquid chromatography (LC) conditions can be improvednusing a separation channel with low-dispersion turns. Thenpillar array column was fabricated by reactive ion etchingnof a silicon substrate. With the low-dispersion-turn geometry,na column with a length and width of 110 mm andn400 μm, respectively, could be fabricated on a 20 × 20nmm microchip. Under nonretained conditions, the solutenbands obtained for fluorescent compounds remainednalmost unchanged even after passing through the lowdispersionnturns; however, significant skewing of thensolute bands was observed in the case of constant-radiusnturns. Two coumarin dyes were well resolved undernreversed-phase conditions, and a maximum theoreticalnplate number of 8000 was obtained. Successful separationnof the fluorescent derivatives of six amino acids wasnachieved in 140 s. These results indicated that thenseparation efficiency of microchip chromatography couldnbe significantly improved using a long separation channelnwith low-dispersion turns.