Dear list, I rapidly received some answers to my question concerning gas purification systems. Obviously the "High Capacity Gas Purifier" from Supelco is a good choice ... ... and that's what Finnigan recommends as a matter of fact!!! Sorry for that! I don't know how this could happen. Somehow the word "puregas" made its way to my notes, which happens to be the product name for the system built by cmc. Anyway, comments on both (or other) systems still are welcome. Sorry, once more ... -- Uli Flenker Institute of Biochemistry German Sport University Cologne Carl-Diem-Weg 6 50933 Cologne Phone 0049/221/4982-493