Dear Michael,
Maybe you absolutely need Iex and maybe the product you want to separate
from TFA is also a small MW molecule but we have the same problem after
detritylation of oligos after DMT-on purification and we are using=20
different techniques that do not involve cartridges or chromato :
ethanol or acetone precipitation,
evaporate to dryness under airflow,
speed-vacing the product at low temperature (<20=B0C),
G25 filtration (home-made or NAP-25/PD-10 - Pharmacia Biotech).
Regarding cartridges, I think that some sep-pak (Waters) could be used.
There are my toughts at the moment, based on our experience.
Good luck.
--=20
Marc LEMAITRE, Ph.D.
EUROGENTEC Bel S.A.
Parc de Recherche Cense Rouge
B-4102 SERAING (BELGIUM)
Tel : (+ 32) 4 366 01 50=20
Fax : (+ 32) 4 367 45 00
E-mail : <mailto:m.lemaitre@eurogentec.be>
Web site : <http://www.eurogentec.be> <-------- check it out !