Fig. 1

Elaboration of a spectroscopic workflow for optimized MP particle detection. (a) The visible image (VIS) represents the standard optical microscope image of unstained tissue; (b) The “tissue”-image shows a chemical image (wavenumber 1660 cm^{- 1}); (c) the “PE”-image shows a chemical image (wavenumber 2855 cm^{- 1}) characteristic for the polymer of interest (here: PE). (d) Final step: “PE/tissue”-image, calculated as the ratio of “PE”- and “tissue”-image, resulting in a clear identification of PE particles at three different positions within the section/region of interest.