Raman is a spectroscopic technique based on light interacting with chemical bonds in a product resulting in specific vibrations. Confocal Raman imaging allows the visualization of the spatial distribution of chemical constituents within a sample in the X-Y-Z plane. The obtained hyperspectral image/cube contains full spectral information in each pixel of the image corresponding to a unique spatial location on the sample. Use of specific peaks or chemometric tools like K-mean clustering or Multivariate Curve Resolution enables the elucidation of known and unknown compounds. Raman imaging is widely used to study different types of materials e.g., foods, packaging, pharmaceutical, cosmetics, material science, etc.
Fig 1: Normalized MCR concentration maps of a spread, showing the spatial distribution of the individual compounds SF, water, solid fat and emulsifier
Figure 2: Packaging foil after K-mean clustering analysis of the Raman image showing the location of the different layers in two batches (left a and b) and the heterogeneous and homogeneous distribution in the LDPE layer in the different batches (right a and b)