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Dry loading tips


I thought I would collect a couple of tips that I found recently in a couple of threads.  Please feel free to add.

Kriggy wrote "b) dry loading is my go-to technique since I dont have to try to dissolve my compounds in mobile phase which they might not be soluble (especially if you work with hexane:EA). As rolnor already said, there are adapters with filters that work well but simple splashguard / bumptrap or whatever you call it with cotton in the connection between the trap and your flask works well. Usually, low boiling solvents like DCM or MeOH are used. Evaporate to dryness, to the state of dry silica."  Whenever there is a substantial fraction of hexanes, we are now automatically using dry loading.  Adapters with fritted glass help keep the silica from going where it should not.

clarkstill wrote, “I used to put a long pipette on my fumehood compressed air line and use it to evaporate any solvent on the inner walls of the column before adding the dry-loaded sample - then all the silica remains dry and doesn’t stick.”  This sounds like a neat trick, and we will try it next time.

Nice with some tips! Whenever you evaporate these guards with a filter eliminates splashing, you can buy these now, I think our group invented them. We custom ordered these from Werner-glas in -94 something, they were not available from glassware-vendors back then.


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