Chromatographers with experience in preparative HPLC know that resolution and loadability are of the utmost importance.
The greater the resolution, the higher the sample load and the faster pure compound is obtained. The ability to optimize resolution at the preparative scale means starting with high performance separations at the analytical scale.
The same features that make ACE ultra-inert base deactivated analytical columns the choice of method development chemists also make them the ideal choice for scale-up and process methods.
ACE preparative HPLC columns are available in a wide range of column dimensions and particle sizes for complete optimization of preparative assays.
For maximum loadability, 30mm or 50mm id columns are recommended. Use a 50mm length ‘combinatorial’ column with a 5μm particle size to maximize the speed of your analysis.
To maximize resolution, choose a 250mm length column with a 5μm particle size.
| Column size | Column id (mm) | Relative flow rate (ml/min) | Weight of phase (g) | Typical injection volume (µl) | Sample capacity per injection Optimum Overload |
|---|---|---|---|---|---|
| Analytical | 4.6 | 1.0 | 2.5 | 10 | 2mg 85mg |
| Semi-preparative | 7.75 | 2.8 | 7 | 30 | 6mg 240mg |
| Semi-preparative | 10 | 4.7 | 12 | 50 | 10mg 400mg |
| Preparative | 21.2 | 21 | 53 | 200 | 45mg 1.8g |
| Preparative | 30 | 42.5 | 106 | 400 | 90mg 3.6g |
| Process | 50 | 118 | 295 | 1200 | 250mg 10g |
| Process | 100 | 473 | 1182 | 4800 | 1g 40g |
The following figure demonstrates a typical preparative method development strategy. Since ACE columns are shown to give reproducible scale-up and are available in the widest range of column dimensions, loading studies may be performed at an analytical level with complete confidence that this can be fully transferred to preparative scale columns.
A fundamental requirement for successful preparative applications is a robust, rugged column. ACE materials have previously been shown to have excellent chemical stability under highly acidic and highly basic conditions. The high mechanical stability of the ultra-inert ACE silica and the unique preparative packing methods employed result in a high efficiency, extremely stable packed silica bed – leading to increased preparative column lifetimes. The following figure demonstrates the excellent column performance maintained with a 50 x 21.2mm ACE 5 AQ column over an extended test period.