ANYL 254 |
| The history of HPLC has seen a progression in the use of columns packed with particles of decreasing size. This has led to smaller values of the plate height and faster optimum velocities. The 400 bar pressure limit of conventional HPLC equipment has resulted, however, not in columns of increasing separation efficiency, but columns offering faster analysis times. By developing systems capable of pressures of 2,000 to 4,000 bar, it is now possible to use half-meter long columns packed with 1 micron particles. Our early work in ultra-high pressure LC was done with non-porous reversed phase packings. While providing efficient separations, the sample capacity (loadability) of columns packed with such particles was limited and prevented optimal coupling to mass spectrometry with good spectral signal to noise. Capillary columns packed with porous reversed phase packings of 1.5 micron diameter have now been prepared, and offer improved performance and loadability. Separations of peptides and intact proteins by ultra-high pressure liquid using porous packings provides significantly increased sample loadability and improved signal-to-noise ratio in mass spectrometry. It is known that high pressures tend to denature proteins and reduce protein aggregation at room temperature in aqueous solutions. Preliminary studies indicate that pressures exceeding 1,500 bar aid in the elution and recovery of proteins from reversed phase capillary LC columns.
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Honoring Milos Novotny, Analytical Chemistry Awardee
8:30 AM-11:50 AM, Monday, 27 March 2006 Georgia World Congress Center -- B213, Oral
Division of Analytical Chemistry |