Table 2.

Features, resolutions, and applications of currently studied MP identification methods. (Republished with permission of Royal Society of Chemistry, from ref. [24]; permission conveyed through Copyright Clearance Center, Inc.)

Identification Method	Feature	Resolution	Application
Microscopy	Simple, fast, and easy No chemical confirmation No polymer composition data	<100 µm	-
Microscopy (+ FTIR/Raman) a	Plastic confirmation of subset samples Polymer composition of major or typical plastic types Possibility of missing small and transparent plastic particles	<1 µm	Major or typical plastic types
FTIR spectroscopy b	No possibility of false positive data by chemical confirmation of all the plastic-like particles Reduction of false negative data Non-destructive analysis Automatic mapping (FPA-reflectance) Laborious work and time consuming for whole particle identification	<10 µm	Well-known spectra can identify microplastics and polymer types.
Raman spectroscopy b	No possibility of false positive data by chemical confirmation of all the plastic-like particles Reduction of false negative data Non-destructive and non-contact analysis Interference by pigments	<1 µm	Using molecular structure and atoms, identify microplastics and polymer types.
Thermal analysis	Simultaneous analysis of polymer type and additive chemicals (pyro-GC/MS) A few polymer identification (DSC) Complex data (pyro-GC/MS)	<10 µm	PE, PP, PVC, PS, PA, PET and chlorinated or chlorosulfonated PE

^a FITR or Raman analysis of subgroup of plastic samples. ^b FTIR or Raman analysis of whole particles.