For DBC no method for the assessment of the degree of
butyrylation—based on FT-IR measurements—is found in
the literature. Several measurement peaks and reference
peaks were investigated but the results were not conclusive
enough to differentiate between the two studied DBC types.
Comparing with a direct technique such as 13C NMR would
yield a series of calibration curves, thus resulting in relevant
FT-IR measurement and reference peaks. This might be the
subject of further study