I am looking for suggestions of good papers discussing the methods currently or formerly used to isolate by cryogenic means the CO2 from other gases prior to CSIRMS. I do have a number of articles containing material on the subject (mainly "we did it like this" descriptions), but rare are those which address the problem from a theoretical or experimental point of view. This may be old or even trivially accepted stuff, but I guess there should be someone somewhere who has once stated the problem right. Thank you! Daniel Michaud Departement de physique Universite Laval Quebec, Quebec [log in to unmask]