Acetonitrile elution

[konkon]

I am working with a small peptide (1.3KDa). I am following some literature to purify it in Sep-pak C18 column. Everything is kind of straightforward but I do not have a lyophiliser (we are not a chemistry lab). So I was wondering, the elution protocol from the paper suggests 50% acetonitrile:50% water for elution. If I would use 100% acetonitrile for elution and then use a vaccum evaporator to evaoparate the Acetonitrile from my peptide, would that work, or any reasons that this cannot work? This way I should not have the issue of having the water left over after the vaccum evaporator.

Any suggestions are welcomed. Thanks, konkon

[tom jupille]

You can certainly try it. Possible issues to watch out for:
Is your peptide soluble in 100% ACN?
Will 100% ACN elute additional impurities?

[konkon]

Thank you for the comment. I suppose I could use 50:50 to do the first purification, back dilute the acetonitrile concentration, rebind and elute with 100%. Not sure if the peptide is soluble at 100% but does it really matter if I am going to evaporate the acetonitrile later on?

Thank you.

[tom jupille]

does it really matter if I am going to evaporate the acetonitrile later on?

Yes, because it has do dissolve in the ACN in order to be eluted from the cartridge. A small peptide *should* be soluble in ACN, but "just because I'm paranoid doesn't mean that the world is *not* out to get me." !