Hello fellow listmembers, I indeed agree with Wolfram on this: "Another word of caution, do not rely on the state of vacuum in any of these tubes. If you need to use reliably (and reproducably) evacuated sample / sampling tubes, do it yourself." Perhaps I can tell how we flush and evacuate our vials: We have made a construction (a long copper tube) with 40 needles attached to it(with a valve between every needle and the tube). This tube is connected a He-supply (ultra pure)on one end and a Turbo pump on the other end. Each of these are attached to the tube via a valve. This way it is very easy to evacuate, flush with He and re-evacuate our vials in no time (40 at a time takes approximately 5 minutes). I might add that this is easy to make and the cost is minimal (if you have a spare turbo pump). Hope this helps, Peter. ________________________________________ Peter Vervloedt Laboratory of Applied Physical Chemistry Ghent University Coupure, 653 9000 Gent Belgium tel.: +32 (0)9 264 6048 fax.: +32 (0)9 264 6230 e-mail: [log in to unmask] ________________________________________ ________________________________________ Peter Vervloedt Laboratory of Applied Physical Chemistry Ghent University Coupure, 653 9000 Gent Belgium tel.: +32 (0)9 264 6048 fax.: +32 (0)9 264 6230 e-mail: [log in to unmask] ________________________________________