Dear all,
Greetings, I wonder if anyone has experienced signal drifting when running
multi-scan acquisition experiments in Topspin 2.1.6 - Avance III 300.
Specifically, natural products samples in D2O with/without buffer for
metabolite profiling.
An example would be taking 128 scans with relaxation delay of 1 sec or as
much as 20 sec. First 16 scans are ok but gradually the spectrum resolution
degrades to the point where it looks like shim on Z2 is off or there has
been a loss of sync when accumulating chunks of 16 scans of data. As far as
I have tried it looks like it only happens with samples in D2O. Autoshim
make things worse. Using Phasing mode PK for real time FT does help to keep
things in order but eventually fails.
Any comments will be greatly appreciated.
Alex
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Alex Nieva
NMR Lab
Chemistry Department
Pontificia Universidad Católica del Perú
51-1-626-2000 x4231
51-980123073
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Received on Fri Aug 31 2012 - 11:35:23 MST