Chromatography Forum

I have been asked to do GPC on some polymers with a number of active sites on them, i.e. they are highly funcitonalized with polar groups such as OH. These things have become somewhat of a "sticky situation" (sorry couldn't resist that one) for me because they tend to adsorb to about every GPC column I've tried like Styrogel, Tosoh TSK-Gel etc.

Does anyone out there know of a good GPC stationary phase that has fewer active sites for these things to adsorb to? I do use a bit of acid as a modifier in the organic mobile phase to try and prevent the phenomenon. It has been hit and miss with most of these molecules. The acid works for some but not for others. I've been told to try the "I-series" columns from Viscotek but I was wondering if anyone had other ideas. Thanks

With biological macromolecules one sometimes does not find an "inert" stat. phase, one has to prevent interactions with a proper solvent. Looks like that´s what you have to do, find a solvent in which your polymer is happy.

The selection of the right GPC packing and the right mobile phase for a particular polymer is not a random thing. People have done a lot of homework on this, and it is partially an art. I suggest to read some chapters on GPC in text books first. A range of recipes are provided in my book on "HPLC Columns".

If you have a complex polymer with multiple functional groups, I may be able to give you some good advice, if I understand the polymer that you are working with. Your description is too vague to help you at this point in time.