Fig. 1

Microplastics extraction process. a Common steps in extraction processes: sieving removes a large proportion of the matrix, density separation removes the heavy inorganics, and matrix digestion removes the organics. b Possible states of microplastic particles in the matrix after aging processes in natural environments and/or after matrix digestion: they can dissolve, fragment, or undergo chemical alteration. c Chemical structures of polymers used in this study: microplastics show different stabilities with different digestion protocols, depending on their polymer backbone