ANYL 133 |
| Within the evolution of HPLC there has become a migration towards using smaller particles to achieve higher column performance and shorter analysis time. The cost of this transition, however, is the need for significantly increased back pressures in order to obtain the appropriate linear velocities. With the increases in the back pressure requirement, special HPLC systems are needed in order to maximize the performance of these columns. The recent trends have been in the use of materials that are below 2 mm in size. These materials typically require between 300-600 bar or more of pressure to operate, depending upon the desired flow rate and mobile phase composition. A typical commercial column packed with 1.8 – 1.9 um materials generate on the order of 190,000 plates/m. Herein we will demonstrate that columns that are packed with a new 2.5 um stationary phase, achieve efficiencies on the order of 150,000 - 160,000 plates/m, almost 90% of the efficiency of sub 2 um columns, at back pressures that are about one third to one half less than those that are generated on the sub 2 um columns. We will also show that with the 2.5 um columns, it is possible to obtain very similar separations to those that are achieved on sub 2 um columns, at back pressures that are compatible with both traditional HPLC equipment, as well as newer systems with higher pressure capabilities. |
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General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Analytical Chemistry |