Subtracting background spectra from sample spectra

[phoebe-sch]

Hi -
For my spectra, I have the sample spectra and the background spectra of the substrate the sample is on. I need to subtract the background spectra from the sample spectra before I begin identifying peaks. Is this doable with spectrochempy? I have searched the user's guide and haven't found background removal. If there is, can you direct me to it?

Thanks so much!

[atravert]

Hello,

Yes it is perefectly doable using the subtraction. For instance, if your sample spectra and background have been recorded in distinct files, you could do:

import spectrochempy as scp

A = scp.read("mydata/sample_spectra.spg")
B = scp.read("mydata/background_spectrum.spa")

A_corr = A - B
A_corr.plot()

or if all your spectra are in a dataset A where the background spectrum is the first one (index 0):

A = scp.read("mydata/all_spectra.spg")
A_corr = A[1:] - A[0]
A_corr.plot()

You can test this directly with one of the sample datasets in spectrochempy. In this case the reference spectrum is the last one (index -1):

import spectrochempy as scp

A = scp.read("irdata/nh4y-activation.spg")
A.plot()

A_corr = A[:-1] - A[-1]
A_corr.plot()
scp.show()

Below is the plot of the dataset A before correction:

and A_corr:

I hope this helps.
Best regards
Arnaud