I am trying to flatten my FTIR spectrum, however I have no Idea how to treat the far-left peak. The spectrum tends to go up in that direction, so in the variant no.1 (see attached picture) I'm trying to set baseline to follow the trend. However I don't know how to interpolate this spectrum, so maybe making baseline flat in that region is okay (variant 2)?
Or maybe in that case, baseline subtraction is an unnecessary guess and it's better to analyse it the way it is?
And by the way, what do you think about these baselines?