13C-labeled nanoplastic model materials: Synthesis and evaluation of their use in ecotoxicology through bioaccumulation studies in aquatic crustaceans

Considerable advances have been made recently to quantify nanoplastics in the environment but their analyses in complex matrices such as biota remain a challenge. Here, we present a novel labeling strategy for quantifying nanoplastics in complex matrices, without interferences or extensive sample preparation (Limit Of Detection ranging from 2 and 50 mg kg^-1 in Artemia sp.). The approach is based on the use of stable isotopes combined with elemental analysis - isotope ratio mass spectrometry (EA-IRMS), as a way to minimize any labeling effects onto the nanoplastic composition and properties, while enabling accurate quantification in complex organic. This quantification method was compared to pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS) to quantify ¹³C-labeling nanoplastics in relevant matrices. ¹³C-labeled nanoplastic model materials, with 214 ± 2 nm diameter, were synthesized without additives (including surfactants). Aquatic crustaceans (Artemia sp.) were exposed to these nanoplastics at different concentrations including environmentally realistic ones. The nanoplastic accumulation was related to the exposure time and concentration (ranging from 0.001 to 7 mg kg^-1), with a tendency for higher accumulation in females. The depuration kinetics showed the elimination of more than 50% of the nanoplastics within the first few hours, and levels below the detection limit after 4 days of depuration.