Organic materials are analysed to identify different plant and animal species, as well as natural or synthetic organic compounds used in producing artworks.
Materials and methods
Various analysis methods are available, depending on the materials studied:
- Optical and electronic microscope imaging is used to identify plant fibres (cotton, linen, hemp, etc.), animal skins (leather), and mineralized organisms (shells, coral, etc.).
- Binders and adhesives used in the paint may be characterised using several methods with varying degrees of precision:
Specific colouring tests are used to distinguish the composition of binders.
Fourier Transform Infrared Spectroscopy is more accurate, making it possible to identify oil, egg, casein, etc.
In most cases, gas-phase chromatography coupled with mass spectrometry is capable of identifying specific organic compounds (linseed oil, poppy-seed oil, rabbit-skin glue, fish glue, organic colouring, etc.).
- Fourier Transform Infrared Spectroscopy and gas-phase chromatography coupled with mass spectrometry are also capable of characterising other products, such as varnish, lacquers, resins, plasticisers, etc.
- Raman spectroscopy is capable of identifying most organic pigments used in paints and dyes.