Solid sample loading is a great way to perform more efficient and consistent flash chromatography. With solid loading you can eliminate the effects of injection volume and solvent on your chromatography. Teledyne ISCO solid sample load cartridges are designed to take advantage of this technique, as outlined in several application notes on the subject [1], and in our how-to video series [2]. Solid sample loading however does require the extra step of either adsorbing your compound to the silica before loading the cartridge, or applying it to a prepacked solid-load cartridge and allowing it to dry to evaporate the solvent.
That’s easy enough, but here’s a neat trick to make solid sample loading even easier!
When adsorbing a compound onto the silica, during solvent evaporation on the RotoVap, a common problem is silica bumping into the bump trap creating a potential loss of sample and the hassle of recovering the silica from the bump trap. A cool little trick to avoid all that trouble is to use the frit that comes with the 5-g solid load cartridge in the bump trap joint to confine the silica to your round-bottom flask during evaporation. These frits can be purchased independently [3], and they are also included with our 5-g empty solid load cartridge caps [4].
Advantages of using frits to contain the silica:
- Great way to avoid cross contamination and clogging
- Inexpensive alternative to glass frit adaptors or traps
- Better sealing than glass wool or cotton plugs, keeping silica securely in the flask
- You can evaporate more rapidly as you don’t have to worry about bumping
- The frits fit most ST 24/40 finishes.
Check out this video [5] to see how to use the frit to fit your bump trap and then use it on the solid load cartridge (if using the 5 gram size)
Let us know what you think and as always we would love to hear back about any other tips or tricks you are using for loading solid samples.
