Chromatography Forum

Hi guys--

How long do your standards (IS and SS) last in the vials on your autosampler? I replaced one of the vials and refilled them and since then, they have been evaporating pretty quickly (half a mil per week, maybe?) This seems too fast, and I wonder if I've installed the vials incorrectly. I'm new at this and have had to train myself. Any info you can give would be super. Thanks!

There is a teflon ferrule that makes the seal at the top of the vial. Replace it frequently. Also check where the tubing enters the top of the vial holder.
In my case the fluorobenzene loss in the headspace makes the 1,2-dichloroethane-d4 recovery fall out of spec. It has been as bad as 1 day, fixed with a new valve rotor, and as good as >1 week.

Ahh, thank you! I may not have had the reservoir tightened up against the ferrule all the way. I noticed the problem all of a sudden when I removed the vial for filling. If this doesn't help, I'll replace the ferrule. Thanks again!!