We have a Bruker WM-360 (360 MHz for proton) with a widebore magnet. I'm
interested in running some Na - NMR spectra for an advanced class at the
undergraduate level. I've attempted to run a spectrum on a 2M solution of NaCl
in H2O / D2O; however, I have not been successful.
Our 5 mm broadband probe is tuned to 95.260 MHz (right in the middle of the
range of the probe) with a signal to noise ratio of 13:1 (the best we could do
with the probe.) The proton channel works fine and shimmed up nicely (but the
Lock signal is VERY weak - CDCl3 does not appear to give a lock signal, but D2O
and CD3COCD3 work fine).
Here's my parameters:
I've adjusted the two-bay preamp boxes to the appropriate settings.
SF = 95.260
SY = 66.224
O1 = 35000
PR = H 2
PW = 16
RD = 1
RG = 400
SI = 8K
TD=8K
NS = 64
SW = 50000
But, I don't see anything. When I adjust the O1 to 15000, the FID doesn't show
it, but a very large (intensity is huge, peak width is appropriate for a signal)
peak appears to the far left of the screen. I've centered on this peak and hit
ctrl-O and rerun the spectrum - only to find nothing.
I'm using a quartz NMR tube.
Am I doing anything wrong? What are the typical parameters for this job?
Mike
Michael D. Mosher
Associate Professor
Department of Chemistry
University of Nebraska at Kearney
Kearney, NE 68849-1150
Ph: (308) 865-8491
FAX: (308) 865-8157
email: mosherm@unk.edu