My email last week mentioning susceptibility plugs generated enough
responses that I've decided to place the handout I give to students
about them on our web site at:
http://cic.chem.wisc.edu/nmr/Guides/Guides.html#general
Don't know if it will help you much--my students get a 5-10 min
discussion that goes with the handout that includes details that
this group would likely find more interesting. But there it is
in any event.
Couple comments to go with that: I in general find the Shigemi
inserts a bit easier to use. I've had a hard time on occasion
getting all the air bubbles out with the Doty inserts (some
delicate work fiddling with the insert rod finally will do it!).
But once the air bubbles are gone, both types of inserts work
fine. Keep in mind with this comment that I've only used the
Doty inserts for "routine" experiments (e.g., 13C direct observe);
when doing water suppression (only a couple times), I've always
used Shigemi. This isn't to say Doty won't work for water
suppression; I just have no experience here.
Gradient shimming seems to work ok with the inserts. In VNMR,
you have to reduce gzwin and remap; something similar in XwinNMR
but I can't remember what (done this only once).
Students (and their bosses) really do not want to spend the
money on tubes that the Shigemi tube sets cost (or even the
Doty/Wilmad plug sets). I have sets that I lend out that have
helped get users to see how useful the plugs/inserts are.
Cheers,
Charlie
>To the NMR community,
>
>In a recent posting, referance was made to "susceptibility plugs". I
>have never heard of them before and checked the Wilmad catalog to find a
>large selection of these gadgets. It appears that they are used to
...
>
>Bob Silverman
>UCLA - Dept. of Pharmacology
>NMR Facility
>
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Charlie Fry Tel: (608)262-3182
Director, MR Facility Fax: (608)262-0381
Chem. Dept., Univ. Wisconsin
Madison, WI 53706 USA email: fry@chem.wisc.edu
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