How to set baseline correction not to change raw spectra

[qtao]

Question: Can we use the raw spectrum after baseline correction to search library?

Answer: When baseline correction is performed on All Channels, which is the default setting, a baseline will be estimated for each mass channel and subtracted from all intensities in that channel. The change on spectra by baseline correction is permanent. However, you can choose to perform baseline correction Only on TIC as follows,

Go to Menu: Configure > Settings
> Baseline Correction
> Choose Only on TIC option
> OK to apply

Then the spectra will not be changed.