Topshim error - NMR Wiki Q&A Forum

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HELLO all nmr wikier,I am facing problem in runing topshim on bruker 500Mhz using topspin 2.1 it finishes with error (field map-signal to noise is too low) while previously I was using quite comprehensively. Topshim is working in 3d shiming and 1d shiming on sucrose sample but not working on 0.1% E.B sample.I have loaded the right shimfile and it is giving good s/n ratio same as was in acceptance test.It is also creating problem in rga it takes several attempt and set rga little bit lower even for strong sample does any body know where is the problem.Thanks in advance for answering.

signal-to-noise shimming bruker

asked Mar 03 '15 at 09:07

feroon
21

very very thanks for replying Clemens yes deuterium pulse is correct and lock channel is tune properly,probe is PHBBI,I have tried in different sample but the result is same field map-signal to noise too low. - feroon (Mar 04 '15 at 04:57)

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Hi, there are a number of possible reasons for this. Are you sure the deuterium pulse is correct and the lock channel is tune properly. What is the type of probe? Such an error can also be caused by convection in the sample. Try "topshim convcomp" and check if the error goes away. Do DMSO-d6 or Acetone-D6 work properly? Clemens

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answered Mar 03 '15 at 20:29

Clemens Anklin
416

updated Mar 03 '15 at 20:34

Hi! Following Clemens lead, if you do not have issue when running Sucrose sample with topshim but have problems with samples in other deuterium solvents. Your field may have drifted, try re-centered the deuterium signal and do edlock in Bruker NMR. Jim

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answered Mar 31 '15 at 06:19

Jim Lin
1

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Asked: Mar 03 '15 at 09:07

Seen: 9,302 times

Last updated: Mar 31 '15 at 06:19

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