What is the difference between silica gel and alumina

Alumina is an excellent support for preparing chemically bonded C18 phases as well as many other ligands. Scaling up from TLC to large scale preparative purification is consistent and reproducible. Once you switch to alumina, there is no going back. We are so certain of it that we are willing to provide you with FREE grams of any requested alumina to try in your laboratory. We are so confident that you will enjoy your experience that we are providing this product to you free of charge.

Just call us for your sample material, and let us know about your requirements. Our technical support team is available to make sure that the transition is seamless.

This offer is limited to one sample per customer. Limitations of Silica While silica has a higher sample load, there are several limitations in the use of silica: The silica backbone Si — 0 — Si hydrolyzes at pH. Alumina displays amphoteric properties. It acts as a weak ion exchanger. Alumina has amphoteric properties with both cation and anion exchange properties over a broad pH range. It has a high surface-area-to-weight ratio and adsorbs more moisture than any other type of desiccant.

Silica gel fractures when exposed to mist, and its adsorption performance degrades when regenerated at high temperatures. Due to these drawbacks, silica gel has more application limitations than other types of desiccants. Silica gel is used in combination with silica alumina in our heated air and gas dehumidifying equipment products. While Silica has proven to be the most widely used polar stationary phase, we see that Alumina also has an important field of application.

Acidic and basic Alumina are useful for the purification of compounds that feature acidic or basic moieties, which interact with the Silanol groups and lead to peak tailing or can even lead to an irreversible adsorption on Silica.

As a further matter, users typically add pH modifiers e. This implies purging of the system and risk of contamination. With acidic or basic Alumina the separation can be run without any modifier and therefore makes the whole process considerable easier. The Silica vs. Alumina dilemma might not find its end with this post but at least we saw how both polar phases complement each other depending on the specific application type. If you have questions, which you would like me to write about on the blog, feel free to fill in the comments.

Bart's blog celebrates its first birthday by welcoming a new guest to the party. Lyophilization will now get regular coverage on the blog! There are challenges in chromatography when it comes to user, sample and environmental safety.

Discover a brand new digital tool for flash cartridge selection. This post is a giant turbo button for your laboratory evaporation performance. There are several methods for filling columns.

You may find one method easier or quicker than the others and always fill a column that way, or you may find that different size columns require different methods. All methods have their pros and cons and you may need to try all three to find the one that you prefer. You will need:. Once you have your products isolated, all that remains is to empty and clean the column ready for next time. To speed up the process, elute all of the solvent using compressed air and allow air to flow through the column for approximately 2 h.

This will give dry, free-flowing silica that is easy to pour into the silica waste container. Alternatively, elute all the solvent and secure the column upside down over a large beaker and allow to dry overnight in a fumehood.

Do you have any tip or tricks for packing the perfect column? Share them in the comments section DOI: Please note that to comment on an article you must be registered and logged in. Registration is for free, you may already be registered to receive, e.