Chromatography Forum

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

The method probably uses that mixture since it is a mobile phase for LC work. You can try straight acetonitrile or methanol and see if that works for you.

Hi
You peptide solve in acetonitrile good or bad ? If peptide not dissolve in acetonitrile (many peptides insoluble in acetonitrile) -You understand that your offer - the benefit of stupidity.
If a good dissolve - may be do , may be not do. Need experiments.

PS - you have'nt Liofiliser ? Brain and hands its is, I hope? And vaccuum pump , glass tubes , big flask with two laps , water cooler or steel tube ( for serpentain condensor) and ice hope to find also &

konkon what do you need to achieve? why do you need to do clean up

are you trying to desalt for example?
where does the peptide comes from?
more details are needed here

i know that a company called AAPPTEC have a nice solution of using the evaporator instead of a lyophiliser, it is a lot cheaper and take yes more time, but it is most certainly better then to have to do it by hand
there are also several types of eveporators out there with tubes also that could be used.

but mostly if the peptide is in solution, why do you not centrifuge and filter simply?
what are your limitations?

is this going to HPLC after the sample prep?
is this simply for storage?
again knowing where you came from and where you want to take the peptide would help a lot

With SPE cartridges you can remove interferences either by washing them off before your elution or leaving them on the cartridge after your elution. The problem of using 100% ACN with a C18 cartridge is that you may well find yourself eluting everything that you loaded. In which case the entire process would be pointless.

So I guess it depends on whether you get sufficient clean up with 100% ACN and also whether or not your peptide is stable in 100% ACN.