IPA vs THF (instead of ACN)

[diablo]

Hello folks,

I've got some question considering IPA and THF: Due to ACN shortage i'm busy with adjusting some RP-HPLC methods (for protein/peptide analysis).
I'm thinking about MeOH/IPA or MeOH/THF mixture - MeOH for lower back pressure and IPA or THF for better protein/peptide solubility...

Can anyone tell me when IPA should be perfered to THF or what the pros and cons of both fluents are ?

thx

[Uwe Neue]

I can send you an article on the selectivity differences that we have observed between the different solvents, published in J. Sep. Sci. This was for small molecules, but it should translate to peptides. All these solvent mixtures with water have a higher backpressure than water/acetonitrile mixtures, but in high water content it is not as detrimental as for the intermedidate composition range. THF gives in general significant different selectivities than acetonitrile or methanol. Mixtures give intermediate selectivities.

[lmh]

Isn't THF nasty for Peek tubing?

[zokitano]

Isn't THF nasty for Peek tubing?

That's right, but for conc. of THF > 50% in the mobile phase

Regards