Yes we can. We primarily use the FT-IR for this purpose. Using the FT-IR (Fourier Transform Infrared Spectroscopy), the composition of solids, liquids and gases can be determined. And this therefore also of an unknown composition.
An image of the solid, liquid or gas is then taken with the FT-IR device. The recording – the analysis using the FT-IR device – produces a spectrum (see top right of the picture).
This spectrum is then compared to a library, which contains more than 300,000 reference spectra. A reference spectrum is a spectrum whose components, functional groups and composition are known. And so by comparing the FT-IR recording of the unknown substance with the reference spectra in this large library, we establish the composition, components and functional groups (see bottom right of the picture).
In addition to determining substances of unknown composition, we also use this technique for 1. confirming the composition of production materials and 2. comparing product compositions. This involves making several FT-IR recordings and then comparing the spectra with each other and revealing similarities and differences.