Did you recalibrate the jump? It is not clear from your message. After a cleaning we usually refocus the plates and commonly do a new mass calibration at the same time. The condition of your source will be in a new state, so an electrical tune up also may be in order.
Good luck, Ben
Manager, Stable Isotope Core Laboratory
Washington State University
School of Biological Sciences
Pullman, WA 99164-4236
Laboratory for Biotechnology and Bioanalysis (LBB2) Stable Isotope Core
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of Ruta Bariseviciute
Sent: Wednesday, September 18, 2013 2:50 AM
To: [log in to unmask]
Subject: [ISOGEOCHEM] Jum Calibration problems in IRMS
We have Delta V Advantage IRMS. We have cleaned the ion source. After cleaning we have problems with Jump calibration (N2 to CO2). Separate N2 and CO2 measurements are good. Has anybody had such a problem? It appeared just after ion source cleaning.