Abstract
Superficially porous columns were originally introduced by Kirkland in the 1970's for the separation of large molecules. The concept appeared to be abandoned in the following decades, but has recently been re-introduced with great success by a number of manufacturers in a format specially designed for the separation of small molecules. These newly introduced columns packed with core-shell particles display excellent performance with minimum reduced plate heights (h = H /dp) often less than 2; that is, well-below the assumed "magical" barrier for packed columns. These exceptionally low values could be
attributed a reduction of the eddy-dispersion (A-term), longitudinal diffusion (B-term), and reduced mass-transfer (Cs-term) contributions to band broadening.
Furthermore, the flow resistance is reduced allowing the use of longer column thereby increasing the separation efficiency In the present study, the gradient performance of columns packed with 2.6 um superficially porous (core-shell) particles is assessed at ultra-high pressure conditions.
The gradient-performance limits are visualized using kinetic plots, depicting the analysis
time versus peak capacity, while operating (coupled) columns at a column pressure of subsequently 600 and 1200 bar. These two pressures were selected to demonstrate the gain in peak capacity that can be achieved when doubling the applicable instruments pressure. A significant reduction of 58% in analysis time could be realized while maintaining the efficiency (peak capacity np = ± 230) by increasing the pressure from 600 to 1200 bar. Furthermore, a substantial gain in efficiency (± 23 %) could be obtained by optimizing the column length combined with an increase in pressure from 600 to 1200
bar, without any sacrifice in analysis time. The effect of optimization of column length and operating conditions is demonstrated with the separation of a complex mixture containing waste water pollutants, alkyl phenones, and parabenes.
attributed a reduction of the eddy-dispersion (A-term), longitudinal diffusion (B-term), and reduced mass-transfer (Cs-term) contributions to band broadening.
Furthermore, the flow resistance is reduced allowing the use of longer column thereby increasing the separation efficiency In the present study, the gradient performance of columns packed with 2.6 um superficially porous (core-shell) particles is assessed at ultra-high pressure conditions.
The gradient-performance limits are visualized using kinetic plots, depicting the analysis
time versus peak capacity, while operating (coupled) columns at a column pressure of subsequently 600 and 1200 bar. These two pressures were selected to demonstrate the gain in peak capacity that can be achieved when doubling the applicable instruments pressure. A significant reduction of 58% in analysis time could be realized while maintaining the efficiency (peak capacity np = ± 230) by increasing the pressure from 600 to 1200 bar. Furthermore, a substantial gain in efficiency (± 23 %) could be obtained by optimizing the column length combined with an increase in pressure from 600 to 1200
bar, without any sacrifice in analysis time. The effect of optimization of column length and operating conditions is demonstrated with the separation of a complex mixture containing waste water pollutants, alkyl phenones, and parabenes.
| Original language | English |
|---|---|
| Number of pages | 1 |
| Publication status | Published - 1 Jun 2012 |
| Event | the 38th International Symposium on High Performance Liquid Phase Separations and Related Techniques - Anaheim, California, United States Duration: 16 Jun 2012 → 21 Jun 2012 |
Conference
| Conference | the 38th International Symposium on High Performance Liquid Phase Separations and Related Techniques |
|---|---|
| Abbreviated title | HPLC 2012 |
| Country/Territory | United States |
| City | Anaheim, California |
| Period | 16/06/12 → 21/06/12 |
Keywords
- Superficially porous particle
- Ultra-high pressures
- Kinetic performance
- Gradient peak capacity
- Kinetic plot
- Coupled column