tailieunhanh - Liquid Chromatography 2

Requires improvements in the whole column: – Sub 2 μm particles Porous for optimum mass transfer New bridged hybrid particle required for pressure tolerance (up to 15000 psi) Sizing technology for narrow particle size distribution – Column hardware New frit technology to retain particles New end fittings for high pressure/low dispersion operation – Packing technology New column packing processes to optimize stability | a W VILLANOVA UNIVERSITY Liquid Chromatography 2 Lecture Date April 14th 2008 Outline of Topics UHPLC - ultra-high pressure liquid chromatography also referred to as UpLCtm as sold by Waters - Smaller particle packed columns Monolithic stationary phases - Dionex ProSwiftTM - Phenomenex OnyxTM 2D LC Micro-HPLC - Eksigent Technologies 8-channel HPLC - NanoStream 24 column HPLC -Other examples Preparative and Simulated Moving Bed SMB LC 1 Particle Size Evolution Late 1960 s 40pm pellicular non-porous coated 100-500 psi bar 1000 plates meter 1m columns 10 min Diagrams from Waters Inc. 10 min Early 1970 s 10pm Irregular micro-porous 1000-2500 psi 71-177 bar 25 000 plates meter x 300mm 10 min 1980 s to present day - 5pm spherical micro-porous 1500-4000 psi bar 50 000 - 80 000 plates meter x 300mm J. R. Mazzeo U. W. Neue M. Kele and R. S. Plumb Advancing LC Performance with smaller particles and higher pressure Anal. Chem. 77 2005 460A-467A. Smaller Particles The evolution of the van Deemter plot Smaller particles provide increased efficiency With smaller particles this efficiency increase extends over a wider linear velocity This provides the ability for both added resolution and increased speed of separation Particles are central to the quality of the separation Diagram from Waters Inc. 2 Faster Chromatography Can Reduce Resolution 5um Re Phase C mL min Compressed Chromatography mL min. 50 mm column Fails Rs Goal of 3 Limitation Time in Minutes Run time is reduced but resolution is lost Diagram from Waters Inc. UPLC Separations