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Separation efficiency of particle-packed HPLC microchips
- Source :
- Analytical Chemistry. August 1, 2008, Vol. 80 Issue 15, p5945, 6 p.
- Publication Year :
- 2008
-
Abstract
- We report an experimental study of separation efficiency in microchip high-performance liquid chromatography (HPLC). For this study, prototype HPLC microchips were developed that are characterized by minimal dead volume, a separation channel with trapezoidal cross section, and on-chip UV detection. A custom-built stainless steel holder enabled microchip packing under pressures of up to 400 bar and ultrasonication. Bed densities were investigated with respect to the packing conditions and consistently related to pressure drop over the packed microchannels and separation efficiency under isocratic elution conditions. The derived plate height curves show a decrease of mobile phase mass transfer resistance with increasing bed density. High bed densities are critical to separation performance in noncylindrical packed beds, because only at low bed porosities does hydrodynamic dispersion in noncylindrical packings come close to that of cylindrical packings. At higher bed porosities, the presence of fluid channels of advanced flow velocity in the comers of noncylindrical packings affects hydrodynamic dispersion strongly. We demonstrate that the separation channels of HPLC microchips can be packed as densely as the cylindrical fused-silica capillaries used in nano-HPLC and that consequently microchip-HPLC separation efficiencies comparable to those of nano-HPLC can be achieved.
- Subjects :
- Integrated circuits -- Design and construction
Integrated circuits -- Properties
Semiconductor chips -- Design and construction
Semiconductor chips -- Properties
High performance liquid chromatography -- Equipment and supplies
High performance liquid chromatography -- Methods
Standard IC
Chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 00032700
- Volume :
- 80
- Issue :
- 15
- Database :
- Gale General OneFile
- Journal :
- Analytical Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.183489658