Dear All,
Last November, I had to replace my nitrogen amplifier on my Inova 600. Since then I've had noise ridges running along my water peak in any spectrum, where a nitrogen pulse is called. If a sample is concentrated we see very little if any of these ridges. However, if the protein is low in concentration the noise bands dominate the spectrum. We've explored multiple causes- shims, PTS, the nitrogen amplifier, gradients, probe. Individually, none of these is the answer. The noise band is 1.8 ppm (10800 Hz) off the water peak. H2O suppression seems to be related to the problem. Has anyone else seen this type of noise? Has anyone solved this type of problem?
Thanks,
Martha
Martha Morton, Ph. D.
University of Connecticut NMR Facility Scientist
Chemistry NMR Lab Director
(860)486-4069
Received on Wed Jul 23 2008 - 06:00:28 MST