THF?

[kamel]

Hello all,
Is there any topic which talk about THE elution.
how to elliminate THF peak from chrmatogram?
thanks.

[tom jupille]

Best and easiest is to have the same amount of THF in both the sample diluent and the mobile phase. That's true of any additive: to do the best chromatography, disturb the equilibrium of your system as little as possible.

[kamel]

thank you for reply.
my diluent is ACN:THF 50:50
mobile phase KH2PO4:ACN 50:50 ,
pH=7.
what does mean "same amount of THF"?
KH2PO4:ACN:THF 50:50:50 ?
thanks again.

[HPLCaddict]

What Tom meant is that the very best approach is solvent = mobile phase, so you don't have an equillibrium upset because of the solvent. If that's not possible, try to be as close as possible to the eluent composition.
Btw ACN/THF as sample solvent? In RP chromatography? Is this really needed? That's quite a strong solvent (concerning elution power) that might mess up your peak shapes, at least for early eluters. Is it really necessary to have THF in the solvent?

[kamel]

thank you very much for reply
I will try to change the method.