200 samples out of a single tube reactor is not too bad. There are many ways to pack them, if you are running the same material all the
time you need to optimize the packing for that type of sample. If you are running many different types of samples it is harder to optimize. If you use chromium oxide and silvered cobaltous you can recycle these chemicals and save lots of cash and hazardous waste. I would use these two chemicals. Usually when a tube fails it is the copper or to much ash buildup. You can increase the life of the copper by injecting less oxygen. Any oxygen not used for your combustion reaction is using up your copper. Give me a call and I will help you optimize your setup.

Mike Elefante, President
Elf Analytical Services, Inc

-----Original Message-----
From: Jonelle Herman - NOAA Affiliate <[log in to unmask]>
To: ISOGEOCHEM <[log in to unmask]>
Sent: Mon, Jan 9, 2017 3:41 pm
Subject: [ISOGEOCHEM] Reactor column used for bulk C/N analysis using the Flash HT plus EA

I was wondering if anyone has had success using a reactor built with chromic oxide, silvered cobaltous, and copper wires, when running bulk C/N analysis on the Flash HT plus EA?  We are currently using the pre-packed reactors with tungstic oxide and electrolytic copper wires. With that reactor we are only able to get about 200 samples through before having to change it out.  We were hoping that if we switched to using the reactor pre-packed with chromic, silvered cobaltous, and copper wires we might get more samples through before having to replace it.

Any advice with this would be appreciated!

Jonelle B Herman
Scientist V, 
(Lynker Technologies Contractor)
Environmental and Fisheries Science Division,
Northwest Fisheries Science Center, 
National Marine Fisheries Service,
National Oceanic and Atmospheric Administration, 
2725 Montlake Blvd. E., Seattle, WA, 98112, USA.