Physicochemical Characterization and Quantification of Nanoplastics: Applicability, Limitations and Complementarity of Batch and Fractionation Methods

Comprehensive physicochemical characterization of heterogeneous nanoplastic samples remains an analytical challenge requiring a combination of orthogonal measurement techniques. Batch methods, including DLS, NTA, tunable resistive pulse sensing, TEM and SEM, as well as fractionation methods such as centrifugal liquid sedimentation and FFF-MALS combined with pyrolysis GC-MS or Raman microspectroscopy were evaluated for size, shape and chemical composition measurements and for particle quantification. A set of reference/test samples, including polydisperse and doped NPLs and inorganic nanoparticles of different morphologies, was used to assess applicability/limitations of the selected methodologies. Particle sizes and number-based concentrations obtained by orthogonal batch methods (DLS, NTA, TRPS) were comparable for monodisperse spherical samples, while higher deviations were observed for polydisperse, agglomerated samples and for non-spherical particles, especially for light scattering methods. Higher resolution techniques, including CLS and TRPS offer further insight with increased size resolution, while detailed morphological information can be derived by EM-based approaches. Combined techniques such as FFF-MALS and -RM can successfully provide complementary information on chemical and physical properties in one single measurement, while pyGC-MS analysis of FFF fractions can be used for mass -based particle quantification.

JRC.F.2 - Technologies for Health