Dear Bruker Users,
I wanted to ask about an issue we've had with autolocking under the TopSpin
version of ICONNMR automation recently. While we were running xwin 3.5 and
to deal with autolocking on solvents with more than 1 deuterium resonance, I
used to deliberately set my BSMS field value to about 25 units or so less
than what was really required. Somewhere along the way, I heard/read that
the auto lockin procedure will always "look" in the same direction. So as
long as my field value was just less than the correct deuterium resonance,
all was well. Thus, with ICONNMR that was bundled with the NMRSuite
software, I never ever had to use the "-noauto" flag for any solvent.
That all changed when we recently upgraded to TopSpin 1.3. I am running the
most recent ICON-NMR version (4.0.3 Build 5 under Windows 2000). When we
simply carried over our old edlock table from xwin, we could not auto lockin
on CD3OD whereas all other solvents, which had only 1 resonance, worked
seamlessly. Methanol failed every single time on many different samples
even though my BSMS field value was still set 25 units below the right peak.
Today I added an entry in the Field Correction column of the edlock table
for methanol and, combined with using the -noauto flag, locking on methanol
with ICONNMR automation works again.
So what I'm really wondering is
a) Does anybody have a feel for why I could get away with this under xwin
but no longer under TopSpin?
b) Should I get busy now and add a Field Correction entry for each solvent
in edlock that has more than 1 resonance and activate the -noauto switch in
ICON as well?
c) Is it still advisable to set the BSMS FIELD to something less than what
the actual number should be?
Thanks for your insights!
Mike
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Michael D. Lumsden, Ph.D.
NMR Facility Coordinator
Room 428, Atlantic Region Magnetic Resonance Centre
Department of Chemistry, Dalhousie University
Halifax, Nova Scotia, Canada
B3H 4J3
phone: 902-494-1635
FAX: 902-494-1310
http://armrc.chemistry.dal.ca
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