NMR instrumentation tests
RDUDLEY (rdudley@ARSERRC.Gov)
Wed, 02 Apr 1997 13:30:18 -0500 (EST)
Jeff and all AMMRL Members,
Yes, Jeff did stand up at the meeting. I hope you all responses to his
request. We have had some lineshape problems on one of our probes and we ended
up running some of the old spec tests. The first thing that struck me were the
samples were dissolved in solvents that I do not normally use. I cannot even
remember the last time I used acetone, I do not even have any. I may use
1,4-dioxane once a year. The number one solvent in our lab is D2O followed by
chloroform. Approximately 99% of our high resolution work is done in these two
solvents. I would like to see meaningful spec tests using these solvents. I
would also like to see reasonable sample sizes (i.e. volumes between .6 and 1
ml) for a 5ml nmr tube.
Most Broad Band Probes are usually optimized for 13C. This means that
the ends have problems. Probes with tuning wands do a better job but the
instrument manufacturers will optimize the probe for a certain frequency range.
Bob Dudley