Hello,
Solvent suppression or in general selective suppression of NMR signals is well established and known in 1D 1H experiments. But how to perform multiple signal suppression (more than one NMR signal) in 2D experiments ? for example perform a COSY with the suppression of two specific NMR signals.
Thank you.
Dear Salem,
I do not have an example of a sequence (sorry), but the approach(es) for solving the problem seems to be the same as for 1D experiments. In a 2D experiment, we are collecting data via just 1D scans, which are then combined in a 2D dataset. So the signal that needs to be suppressed should be removed from each 1D-slice dataset and it will not be in the respective 2D spectrum. There are several techniques to do that. But it will require an updated 2D sequence with additional suppression blocks of sequence instructions.
Appropriate relaxation or diffusion "filters" may help as well as RF- or gradient-selective protocols.
Dear Alexander Sagidullin Thank you for your valuable feedback! I was looking for a practical way to add those suppresion blocks in 2D experiment and it is not that obvious when your NMR pulse prgramming knowledge is limited. But your answer confirms my initial thoughts. Thank you again.
Salem.
Dear Clemens Anklin
it's a pleasure to hear from you !I am analyzing samples of diverse nature, so the signals I would like to suppress in order to reveal those of interest, are sample-specific and can have very different chemical shifts (they can be anywhere in the conventional 20ppm 1H SW). I have a purge sequence that works fine on water signal in 1D and 2D (COSY). However, I am very limited when it comes to suppressing more than one signal especially in a 2D experiments like COSY. Currently, I am trying different 1D suppression pulse programs (zgpg, zgcppr, zgesgp, ROBUST-5) in order to find the most appropriate optimal one, in other terms, maximum suppression of the selected signal with minimal loss of other signals (tiny signals of interest). Also As I asked I would like to find a method to easily implement multiple signal suppression in a 1D and 2D experiments (a method that I would modify according to the nature of the sample or in other terms to the signals I would like to supress).
Thank you for your practical guidelines!
Salem.
Hello Salem, I suggest you watching this video may help you get a vision about it.
https://lnkd.in/eiy2J4k5
Dear Salem,
as you have a NEO console I recommend the wavemaker toolbox. With this toolbox you can create a shaped pulse (e.g. sp2) which in your case most likely will be just a rectangular pulse with several phase-modulations. The syntax is easily understood - a manual is part of Topspin installation.
This sp2 pulse is finally used (like Clemens mentioned) in a usual way in any 1D or 2D pulseprogram which starts with a selective pulse for multiple presat like:
p20:sp2 ph0
I hope this helps....for sure Clemens Anklin can also help with this toolbox!
Good luck
Alfred
P.S. You will have trouble however if you have non-deuterated solvents with multiplets (e.g. Ethanol....)
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