Signal Suppresion

Signal Suppression (Not available in Mnova Lite): Strong solvent resonances with solutes of low concentration can result in a lot of problems relating to spectrum quality. One of the primary challenges in obtaining High resolution NMR spectra of biological samples is the suppression of the water resonance to prevent it from overwhelming the signals of interest.

This option is intended to suppress the solvent signal but can also be used to remove any other signal from the spectrum. To suppress the signal, you can select the method (algorithm) of the suppression and the selectivity (or width of the filter; a higher value of selectivity will suppress a narrower band). You can choose the signal, or signals, by double clicking on the applicable table titled 'Signals to Suppress'.

signalsuppression

lightbulb

Utilities:

The 'Signal Suppression' tool is extremely useful when working with proteins, in which spectra are usually measured at very low concentrations in aqueous solutions.

Here you can see an example:

signal suppresion

More information about the signal suppression methods can be found here:

Convolution method: Marion, D.; Ikura, M.; Bax, A. J. Magn. Reson. 1989, 84, 425.

Wavelets: http://www.ebyte.it/library/docs/nmr08/NMR_Wavelet2DFiltering.html

In particular, the following reference was used to develop the signal suppression algorithm using Wavelets:

Günther U.L., Ludwig C., Rüterjans H.,
WAVEWAT - Improved Solvent Suppression in NMR Spectra Employing Wavelet Transforms
J. Magn. Reson. 156, 19-25 (2002). doi: 10.1006/jmre.2002.2534.

Whittaker Smoother: https://onlinelibrary.wiley.com/doi/abs/10.1002/mrc.4747