What SPE cartridge to use? (different polarity separation)

Question

Hello

i have a 95% purity liquid sample (i would call this COMPOUND A), with an average polarity.

I have in it this 2% impurity (I would call it COMPOUND B) , less polar.

What kind of SPE I can use to separate this?

My sample A is soluble in methanol, hexane, acetone, acetonitrile but not in water.

I can separate the two compound using hplc C18 , isocratic WATER/METHANOL 25/75 :

-compound A leave the column at rt 15 min

-compound B leave the column at rt 37 min

I want to try SPE just to separate the two compound at atmospheric pressure....ok using a little only a little pressure.

Thank you.

Dr. Know · Accepted Answer

The best really would be to call Agilent Italy to discuss this. Without knowing anything about the structure of your analytes it is difficult to predict. You can still use what you already know and take a C18 cartridge and use the same solvent mix as for the LC analysis. Compound A will elute before Compound B as it has only half of the retention, but SPE isn't as efficient as LC, you don't have a lot of plates in SPE, so elution profiles are broad.