Solvent Supression with Processing

In spectra with one or more large resonances, it is best to suppress them with acquisition. See:
Solvent Suppression
or
Multi-Frequency Solvent Suppression



It is possible to remove signals such as large solvent peaks with processing as well.

1) To access Signal Suppression, it is under the Processing tab then Signal Supression.

2) Normally, choose Convolution under Method.

3) For position, enter the Chemical Shift of the peak to suppress.

4) For Selectivity, the higher the number the narrower the band of suppression. The maximum is 64, so typically start at 64 then decrease the number until the suppression is sufficient. With a selectivity of 64, there is some suppression +/- 0.1 ppm from the center.

5) If you need a narrower band of suppression, choose Wavelets rather than Convolution. Then adjust the Dyadic Levels. The higher the Dyadic Level, the wider the band of suppression. Higher values of Daubechies Coefficients gives somewhat better results as well.

6) After using Signal Suppression it may be necessary to rephase the spectrum and adjust the baseline. For this see:
Phase Correction
and
Baseline Correction