Yes, I was thinking of your lab setup--Megan Mekoli told me you were strictly cylinders. Does your system include any sort of purge valve to use when switching argon sources? I currently use just a simple T with cutoff valves for 2 sources, but there must be a slow leak someplace since the plasma invariably goes off when I open a valve, even when the second tank is already hooked up.
I do do overnight speciation runs, so dewars are nice then. The issue is I can go weeks without using the ICP-MS. Since the dewars loose so much to venting, I also keep cylinders around. It would be nice if I could limit buying liquid argon to those times when I KNOW I will be using it, and just have cylinders for the rest of the time.
Mary C. Carson, Ph.D.
Center for Veterinary Medicine
Office of Research, Division of Residue Chemistry
U.S. Food and Drug Administration
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