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- Posts: 30
- Joined: Tue Sep 07, 2004 11:58 am
Is there anybody really well versed in Tuning of the MSD5973?
I reinstalled this instrument together with a GC6890 after moving of our lab and now got some trouble with the MS parameters.
First something was completely wrong and I got spectra where the masses were shifted by 2 to 4 mass units. Probably I had a wrong tune file, the masses are all right again. But still the relative abundances listet in the tune report and also the abundances of the isotope masses are different from those in old tune reports collected over years (the instrument was bought in 2001).
The tuning substance is PFTBA with the characteristic masses 69, 219 and 502. The relative abundances are 100 for mass 69 (per definition), about 90 for mass 219 (earlier <50) and about 12 for mass 502 (earlier <5).
The isotope 503 of mass 502 is badly resolved compared to earlier reports.
What can I do to solve this problem and is it really a problem? The chromatography is working, but I'm not sure if might still be a shift in the masses.
Thanks for any help
Emsman
