Derivatization of model samples of natural resins with similar composition for FTIR spectrometric analysis
Abstract
The terpenic resins have been (and they still are) the main compound of painting varnishes, varnishes on musical instruments and furniture. The infrared spectrometry (FTIR) is a non-destructive method often used for confirmation of presence of these resins in art works.
However, the FTIR does not allow mutual distinguishing of the terpenic compounds, because their FTIR spectra are very similar. The chemical composition of terpenic resins is similar, since these contain the same functional groups, but their numbers, ratios and spatial location in the molecule are different.
For better distinguishing of individual natural polymers using FTIR spectrometry the optimal conditions for derivatization (in this case fluorination) of samples had been sought. First, the FTIR spectra of pure non-fluorinated resins were measured, then various conditions of fluorination were tested.
Based on the experiments, the optimal fluorination conditions were determined, which led to the most legible differences in the FTIR spectra of individual natural terpenic substances.