Separation of piperidine from proteins after AIC - (Dec/14/2007 )

I have many fractions from protein anion exchange chromatography purification. Fractions contain (in addition to proteins) buffer with piperidine and 0-1M NaCl, pH = 11.

Could you suggest, how can I easily and effectively remove proteins (from many fractions) from that piperidine buffer?
I would like to use acetone to precipite proteins (because it is cheap, effective and proven), but I do not know whether the piperidine would not interfere somehow with the protein acetone precipitation. Do you know it?

Many thanks.
victor

acetone or ammonium sulfate precipitation should work or you could try diafiltration with an amicon stirred cell.