Dear friends,
Our Year 2000 Inova-500M NMR recently developed a problem in that there
is a group of non-phased peaks at the center of the proton spectra,
where tof is. These peaks are small when sample concentration is high,
and large when the sample signals are small. I assume they have constant
intensity, just being scaled down or up depending on the intensity of
peaks from our samples. I assume it is either a problem with imbalance
of quadrature detection or some kind of DC offset, related to the
receiver, but I have never bumped into this before and am not sure how
to adjust them. Talking to Varian (Agilent), and I was advised to
replace the receiver board. Before I approach my chair for $10k for this
seemingly ultra-expensive board, I would like to know if any Varian
users can advise me about the underline problem and how to fix it
inexpensively, if it is possible. Any suggestions would be highly
appreciated, especially in this tight budget climate.
Thank you very much.
Best regards,
Wei Li
--------------------------------
Wei Li, Ph.D.
Associate Professor and Director of NMR Facility
University of Tennessee Health Science Center
847 Monroe Avenue, room 327
Memphis, TN 38163
901-448-7532 (PH) 901-448-6828 (Fax)
http://www.uthsc.edu/pharmacy/pharmsci/faculty/wli/
Email: wli_at_uthsc.edu
Received on Wed Feb 23 2011 - 09:17:49 MST