Dear All,
in summary of the as-usual excellent input from the community regarding shimming of non-deuterated sample, there are 3 points that stand out:
1) It was reminded, of course, to start with a good set of shims, preferably optimized on an "easier" sample.
2) The preferred command is by far "topshim 1h lockoff o1p=<> selwid=<> (convcomp) ". Some have written AU program to automatically get the "o1p" value from a 1H spectrum (attached). This command can also be placed in iconNMR (link<
http://www.chem.wisc.edu/~cic/nmr/Guides/Ba3vug/AV3_noD-NMR.pdf>).
3) But even simpler: in the case of the presence of a coaxial insert with d-solvent: it may be worth trying to autoshim normally on the smaller inner volume. It will at least take you a step forward.
The fact that I am using ionic liquids (salty and viscous) did not help my case, but I was finally able to automate the shimming using these valuable tips.
I'd like to thank Sebastian, Charles, Kristopher, Robin, George, Eric, Geoffrey, John, Clavin, Virgil and Chris for their input.
Best regards
Chris
From: Fares, Christophe [mailto:fares_at_mpi-muelheim.mpg.de]
Sent: Donnerstag, 21. April 2016 11:04
To: ammrl_at_ammrl.org
Subject: AMMRL: shimming on non-deuterated sample with insert
Dear NMR-Community,
I was wondering if I could find some tips or comments out there on how to program an automatic shimming using topshim (I have topspin 3.2 installed) for a particular sample series that we are currently measuring. These samples contain no standard deuterated solvents but rather a non-deuterated ionic liquids. In order to lock we have a DMSO-d6-filled insert (1mm insert inside the 5mm tube).
I know it is possible to shim on a selected 1H lines but I haven't had much success yet. I tried the AU programs LCTSHIM, LCZSHIM or simply running 'topshim 1h o1p= selwid= ', but these did not give satisfying results so far (and I need it to be reliable for automation). Perhaps I am doing something wrong. If anyone out there runs LC-NMR or other non-deuterated sample types on a regular basis and want to share their approach/experience, I would be immensely grateful.
Best regards,
Chris
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Christophe Farès, Ph.D.
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NMR Department/NMR Abteilung
Max-Planck Insitut für Kohlenforschung/ Max-Planck Insitute for Coal Research
Kaiser-Wilhelm Platz 1
45470 Mülheim an der Ruhr
Tel: +49 208 306 2130
E-mail: fares [a] mpi-muelheim [.] mpg [.] de
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Received on Tue May 03 2016 - 23:32:01 MST