Hi Mary. We use a two cylinder changeover manifold from Linde. It has all stainless steel connections and had served us well. We do not have a loading dock so we must use cylinders for our ICP and ICP-MS. One thing to keep in mind for long or unattended runs (more than one tank) is variation between cylinders even within the same gas lots. If you are running Se this can be a major headache as the Kr levels in cylinders are quite variable. Since Se (at least on our system) is less sensitive, it leads to different backgrounds at 82 and can lead to blank and sometimes CCV recovery failures after the change to a new cylinder. Using the same gas lots should be a simple solution but that doesn't take into account these tanks aren't always purged or purged properly between fills and Kr can build up over times just like in a dewar. Hopefully you don't routinely report Se so this won't be a consideration for you but I thought I would mention it in case it wasn't in the archives
Glenn Hyland | Chemical Analyst III | [log in to unmask]
Public Health Madison & Dane County | 210 MLK Jr. Blvd, Rm. 507 Madison, WI 53703
Phone: (608) 243-0348 | Fax: (608) 266-9730 | Facebook | Twitter
Healthy People. Healthy Places.
It is important to us to protect your confidential information. Please be aware that emails sent or received by Public Health-Madison & Dane County employees are subject to open records requests and can be released to the public, unless there is an exception allowed by law. Thus, we do not discuss your confidential information over email. We will gladly talk to you over the phone instead.
From: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's). [mailto:[log in to unmask]] On Behalf Of Carson, Mary C
Sent: Monday, June 11, 2018 4:11 PM
To: [log in to unmask]
Subject: Looking for recommendations for a changeover manifold for a 1 ICP-MS lab
I did search the archives, and the most recent post seems to date to 2004. We have 1 ICP-MS and 1 operator (me). I do other things sometimes. So I find the ICP-MS seems to alternate between sitting idle, sometimes for weeks, and being used 24/7. Liquid dewars of argon inevitably blow off during idle times, sometimes leaving me without argon. I will sometimes use 2 compressed cylinders simultaneously to get through an overnight run. I am think of installing a manifold system, preferably that could take either cylinders or dewars. Getting a 16 cylinder pallet doesn't really seem practical for my lab setup. I have one quote so far for a 4 cylinder manifold, but it uses a brass header, which I believe would be part of the flowpath. Is this problematic when doing trace analysis? I am under the impression I should stick with SST. Are there vendors out there other than Airgas or Tescom that I should be looking at? Does anyone else use a changeover system that can be supplied by either compressed cylinders or liquid dewars, depending on anticipated use?
Mary C. Carson, Ph.D.
Center for Veterinary Medicine
Office of Research, Division of Residue Chemistry U.S. Food and Drug Administration
[log in to unmask]<mailto:[log in to unmask]>