Lake basins can behave as accumulators of microplastics released in wastewaters as such
or resulting from degradation of larger items before and/or during their journey toward the marine
environment as a final sink. A novel multianalytical approach was adopted for the detection and
quantification of microplastics with size < 2 mm in the sediments of the volcanic lake of Bracciano,
Italy. Simple analytical techniques such as solvent extraction/fractionation (for polyolefins and
polystyrene) or depolymerization (for polyethylene terephthalate, PET), along with chromatographic
detection (SEC and HPLC), allowed quantitative and qualitative determination of the main synthetic
polymer contaminants. In particular, PET microplastic concentrations of 0.8-36 ppm were found, with
variability related to the sampling site (exposure to incoming winds and wave action). Proton Nuclear
Magnetic Resonance (1H-NMR) and Attenuated Total Reflectance Fourier Transformed InfraRed
(ATR-FTIR spectroscopic investigations supported the identification and chemical characterization
of plastic fragments and polymer extracts. The average molecular weight of solvent extractable
polymers was evaluated from 2D 1H-NMR diffusion ordered spectroscopy (DOSY) experiments. The
proposed, easily accessible multianalytical approach can be considered as a useful tool for improving
our knowledge on the nature and the concentration of microplastics in sediments, giving insights on
the impact of human activities on the health status of aquatic ecosystems.