[ROSETTA]

Hi, wondering if someone can help me.
In size exclusion chromatography, the packings have pores, which some of the analytes fit in.  The larger analytes will not, and therefore will be eluted first.  Please can anyone tell me, if this chromatography still uses organic-aqueous mobile phases, and if my understanding of it is correct
Many thanks
Rosie

[Arkcon]

Historically, solvents were avoided because the pacing material would swell, changing the pore size, or otherwise damaging the media.  They have become more robust lately, so you can add a little solvent, but many people tend to avoid that, out of old prejudices.

The mobile phase is typically a pH buffer, and fixed ionic salt concentration.   Whatever's needed to keep the analyte in the correct 3-D structure for proper analysis.   This is usually clear, when you consider analytes, they are either large biomolecules , or synthetic polymers.

[Alpha-Omega]

There are some excellent references available regarding size exclusion chromatography at www.dionex.com

If you go to the search field at the top and type in ion exclusion chromatgraphy it will bring you to a number of references:  data sheets, column operator manuals, application notes, technical notes, and application updates.

These articles will give you a great deal of detail on the packings and recommended eluents for ion exclusion chromatography.

About 6 months ago I took a short course at Dionex COE given by David Carr HPLC Method Dvelopment (also covered ion exclusion) with David Carr...have to say it was the bomb....

Additionally, I do know of a site dedicated to chromatography (separation science) where all the heavy hitters reside (Dionex, Metrhom, Waters, Agilent):  www.sepsci.com/chromforum/index.php


Piece of advice:  if you try and register on that site you cannot use a yahoo, hotmail, gmail...a free address have to use a professional e-mail address or paid isp address.

All the leading experts in chromatography are on that site/forum daily.