Spectroscopy baseline constructions

The choice of the reference band (or bands), however, influences less the results than the reproducibility of the baseline construction and the correct reading of the maxima. Modern software in FTIR spectroscopy are useful in automatic and reproducible location of baselines, maxima, integral values, and baseline-corrected absorbances. 

It is usual in quantitative infrared spectroscopy to use a baseline joining the points of lowest absorbance on the peak, preferably in reproducibly fiat parts of the absorption line. The absorbance difference between the baseline and the top of the band is then used. A baseline construction is shown in Figure 5.2a. 

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