Dear Bummers,
The obvious solution mentioned for autolock on toluene unfortunately
does not work. If you set the aromatics in the edlock file, it will lock
on the methyl. Higher field does not help. We run into this all the time
at 500 MHz.
At this point the only solution is to use a manual lock. Just read in
the parameters from the edlock file using the lopoi command, then press the
LOCK (not AUTOLOCK) button. This problem is one that I have had
discussions with Bruker about. I am told that there are plans to deal with
it, but to the best of my knowledge nothing has yet been implemented. This
is a continual problem for us because I have a lot of users using toluene,
THF, and various mixtures of deuterated solvents. I would hope that a
solution is made available relatively soon.
Jane Strouse
>Return-Path: <bum-list@purcell.cchem.berkeley.edu>
>From: "Kirk Marat" <kirk_marat@umanitoba.ca>
>To: <bruker-users-mail@bloch.cchem.berkeley.edu>
>Subject: BSMS Autolock function on Toluene-d8
>Date: Mon, 21 Aug 2000 15:14:33 -0500
>X-MSMail-Priority: Normal
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>
>The BSMS AutoLock function (used by the XwinNMR "lock" command,
>IconNMR or from the BSMS keyboard) on our Avance300 always
>locks onto the aromatic rather than the methyl peak of toluene-d8. Since
>the
>edlock table has the lock shift set at 2.09 ppm (methyl) the resultant
>spectrum is
>displaced by ca 5 ppm. The obvious solution is to change the edlock table
>to have the shift of the toluene ring deuterons, but I would rather lock
>onto
>the methyl as it is sharper and gives a somewhat better shim. What do
>other
>people do when using toluene? Do you have a way of convincing the AutoLock
>function to pick the methyl group? or do you simply manually lock onto the
>methyl?
>or do you lock onto the aromatic peaks.
>
>On higher field machines the aromatic peaks would be spread out (and thus
>less intense) so that AutoLock would pick out the methyl as the strongest
>peak.
>
>Cheers
>-Kirk
>
>Kirk Marat, Ph.D., NMR Facility Manager
>Dept. of Chemistry and Prairie Regional NMR Centre
>University of Manitoba
>Winnipeg, Manitoba, R3T 2N2, CANADA
>kirk_marat@umanitoba.ca
>ph. (204) 474-6259, FAX (204) 474-7608
>
Dr. Jane Strouse
Dept. of Chemistry and Biochemistry
UCLA
Los Angeles, CA 90095-1569
(310)-825-9841 - voice
(310)-825-0393 - FAX
strousej@chem.ucla.edu
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