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- Posts: 6
- Joined: Thu Mar 11, 2021 6:43 pm
I am using a z-HILIC column to separate an extract containing a bioactive compound. I collected fractions and when I assess each fraction for activity, I see some non-specific inhibition against my cells, which I assume is from the solvent/buffer system.
I am using 98% ACN and 98% H2O, both with 7mM Ammonium Acetate as my buffer. I dry down samples with N2 (compound is most stable with this method of drying) after fraction collection. The fraction volume collected is 100x greater than the volume I must resuspend in to detect biological activity.
I noticed between 10-20 minutes of my run (when H2O is a larger portion of the gradient), a large amount of what appears to be ammonium acetate salt remains at the bottom of my tube (and it smells strongly). I have gone as far as drying these fractions 3x to remove the buffer, but I am still seeing the inhibitory effect of acetate on my cells.
Why can't I remove the volatile buffer?