Dear all readers,
background signal is a troublesome item.
It depends about how much real NMR signal is there in and what comes from the
glass tubes.
https://secure.nmrtubes.com/accessories/fluoropolymer-liners-liner-tube-kits
This is the first workaround to measure glass free in the probe. The background
of the glass tube has gone. But there is still a background left. These is
from the inner glass material of the probe.
http://u-of-o-nmr-facility.blogspot.com/2008/06/11-b-background-signals.html
The broad background of the glass signal has a short T2 time. This happens
in the first part of the FID.
There is an option to optimize the first datapoints from the FID by recalculation
of these from the main or rest signal.
This is linear prediction backwards. Take 32 or 64 first datapoints of the FID
out and recalculate these.
This removes the glass signal - the rest is a sharp and small signal from the
chemical compound.
http://u-of-o-nmr-facility.blogspot.com/search?q=linear*prediction
The cryo...au program uses also the linear prediction stuff to flatten the
spectra.
There are also some pulse sequences for background suppression. All have some
pros and a lot of cons in itself.
Especially you have also these troubles in the solid state stuff - there is
the echo sequence often useful.
Try, pry, error - test for the best.
Yours sincerely,
Ulrich Haunz
--
=========================
Ulrich Haunz, Dipl.-Ing. (FH)
NMR-Spektroskopie
Raum L 710, L 807
NMR-Center M520, M521, M527
Postfach M 715
Fachbereich Chemie
Universitaet Konstanz
78457 Konstanz
Tel.: +49 (0)7531 88-4261 -> M521 Bruker Avance NEO 800
Tel.: +49 (0)7531 88-4422 -> L807 JEOL Lambda 400
Tel.: +49 (0)7531 88-4955 -> L710 Bruker AVIII HD 400
Tel.: +49 (0)7531 88-4956 -> M520a Bruker AVIII 600
Tel.: +49 (0)7531 88-4957 -> M527 Bruker AVIII 400 Automation
Tel.: +49 (0)7531 88-4958 -> M520 Bruker AVIII 400 WB
Tel.: +49 (0)170 9153213
FAX : +49 (0)7531 88-3898
=========================
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Received on Thu Jan 11 2024 - 08:52:29 MST