Bruker has been offering gradient shimming in a variety of ways for
quite some time now. Depending on your hardware you can to 3D shimming
to optimize all available shims and 1D shimming for Z shims. The latter
can be done on 1H with water samples or with selective excitation on
normal samples with one reasonably strong singlet. For regular organic
samples you can use deuterium gradient shimming using the solvent
resonance. This 2H shimming requires one additional piece of hardware to
switch the lock channel between pulsing and locking.
As for the results. Our experience shows, that the methods are tolerant
towards, particles, cheap tubes and reasonably short samples. If the
sample is mispositioned in a way that part of the coil is empty, you
will have problems, but try shimming that by hand.
There is some bad news though. We are not offering this on a X32 based
spectrometer.
Regarding your question about simplex shimming. There are many
parameters affecting speed and quality of this method. We have tried
many different combinations and have found that one can obtain excellent
results in ca one minute. Autoshimming will take longer if the sample is
short.
Best Regards
Clemens
-- Clemens Anklin, Ph.D. Director of NMR Applications Bruker Instruments Inc. Phone:(978)667-9580 ext.144 19 Fortune Drive Fax:(978)667-2955 Billerica MA 01821 e-mail:clemens.anklin@nmr.bruker.com visit our WEBSITE at http://www.bruker.com