13C-labeled nanoplastic model materials: Synthesis and evaluation of potential uses for experimental works through bioaccumulation test studies in aquatic crustaceans

Considerable advances have been made recently to quantify nanoplastics in the environment but complex matrices such as biota remains a challenge. We propose for the first time, a labeling strategy to quantify nanoplastics in complex matrices, without any interferences or extensive sample preparation, using an elemental analyzer coupled with an isotope ratio mass spectrometry (EA-IRMS) and compared to Pyrolysis gas chromatography mass spectrometry (Py-GC/MS), to study the uptake of nanoplastics in aquatic crustacea.

¹³C-labeled nanoplastic model materials were synthetized mimicking naturally aged plastics and ensuring their stability in a wide range of media, from freshwaters to seawater. Aquatic crustaceans (Artemia sp.) were exposed to these nanoplastic model materials at different concentrations, including environmentally realistic ones. The uptake was directly related to the exposure time and concentration, with a tendency of higher accumulation in females. The depuration kinetics indicated a depuration in two steps. Our study demonstrates the potential of ¹³C-labeling, associated with EA-IRMS detection, and offers a new labeling strategy to quantitatively track nanoplastics in complex matrices, strategy that could be applied to a wide range of experiments and in the same way to other stable isotopes. This approach allows for an increased understanding of the impacts of nanoplastics on marine organisms under realistic exposure conditions, through the development of analytical protocols, with detection limits  (LOD) and quantification limits (LOQ) reaching 2 mg.kg⁻¹ and 7 mg.kg⁻¹, respectively, in aquatic crustaceans.