We are experiencing an “interesting” problem with our EA cryogenic  
trapping setup, which is similar to VG’s triple trap but with Valco  
valves: during analysis the ratio traces display pronounced spikes  
whenever the valves on the trapping system are activated (i.e. during  
the freeze cycle for the next sample). The timing is perfect. I  
suspect a drop in air pressure that causes a cross-leak somewhere in  
the changeover valve block. Does that make any sense??? We have no  
problems with manifold or Zero runs.
Any help would be greatly appreciated!
Cheers,
Andrea


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Dr. Andrea Lini
Department of Geology
University of Vermont
Burlington, VT 05405 U.S.A.
Office: (802) 656 0245, Lab: (802) 656 9079
Fax:   (802) 656 0045
http://www.isogeochem.com
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