Comparison of capillary zone electrophoresis performance of powder-blasted and hydrogen fluoride-etched microchannels in glass.
The applicability of glass chips with powder-blasted microchannels for electrophoretic separations was examined, and the performance was compared to microchannels etched with hydrogen fluoride (HF), using bicarbonate buffer and rhodamine B and fluorescein as model compounds. The measured electroosmotic mobilities in all chips were comparable, with values of ca. 7 x 10(-4) cm(2) V(-1)s(-1). The effect of electrical field strength and detection length on the separation efficiency was monitored. It was found that the main source of dispersion is of the Taylor-Aris type, which was discussed in relation to channel roughness differences. Although in powder-blasted channels with a separation length of 8.20 cm, 7-9 times lower plate numbers were obtained than in a HF-etched channel with similar dimensions, successful separation of five fluorescein isothiocyanate (FITC)-labeled amino acids was obtained on a powder-blasted chip within 80 s. Efficiencies of up to 360 000 plates/m were demonstrated on this chip, when a higher buffer concentration was used at a field strength of 664 V/cm. It can be concluded that powder-blasted microchannel chips, although they have a lower separation efficiency compared to HF-etched chips, perform well enough for many applications. Powder blasting can therefore be considered a low-cost and efficient alternative to HF etching, in particular because of the possibility to fabricate access holes through the glass with the same process.
Pu
Qiao-Sheng
QS
MESA + Research Institute, University of Twente, Eschande, The Netherlands.
Luttge
Regina
R
Gardeniers
Han J G E
HJ
van den Berg
Albert
A
D000596:Amino Acids / Q000302:isolation & purification; D019075:Electrophoresis, Capillary / Q000295:instrumentation*; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D005898:Glass; D007202:Indicators and Reagents; D008855:Microscopy, Electron, Scanning; D008904:Miniaturization; D009995:Osmosis; D013499:Surface Properties
D000596:Amino Acids; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D016650:Fluorescein-5-isothiocyanate