[Smoking_meats]

Whenever I dry load my sample, I always get at least some of the solid stuck on the walls of the column. When I try washing it down with solvent, I don't get all of it, and end up using loads of solvent leaving me paranoid that I'm messing up the separation and wasting way too much time.

How do I avoid this or keep it to an absolute minimum? I want to know how to load the sample as neatly as possible.

Thanks!

[kriggy]

First of all, be sure you have the dry loaded compound as dry as possible. Second, use appropriate amount of sorbent (I try to have less than 0,5cm layer of the sorbend after its loaded on the collumn, dont have any more specific guide, I just eyeball the amount). Last, if it sticks to the walls of collumn (like it always does) I rinse it with mobile phase under bit of pressure to get it from the walls (think syringe and needle kind of pressure)

[clarkstill]

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 doesnt stick.

[wildfyr]

Rinse the dry stuff off the sides using a really bad solvent like hexane. If your compound doesn't run at all in hexane (many don't) then this won't smear your load.

Also, Clarkstill makes an excellent observation and suggestion about the sides of the column.