Detection of nanoplastics in food by asymmetric flow field-flow fractionation coupled to multi-angle light scattering: possibilities, challenges and analytical limitations
- 409 Downloads
We tested the suitability of asymmetric flow field-flow fractionation (AF4) coupled to multi-angle light scattering (MALS) for detection of nanoplastics in fish. A homogenized fish sample was spiked with 100 nm polystyrene nanoparticles (PSNPs) (1.3 mg/g fish). Two sample preparation strategies were tested: acid digestion and enzymatic digestion with proteinase K. Both procedures were found suitable for degradation of the organic matrix. However, acid digestion resulted in large PSNPs aggregates/agglomerates (> 1 μm). The presence of large particulates was not observed after enzymatic digestion, and consequently it was chosen as a sample preparation method. The results demonstrated that it was possible to use AF4 for separating the PSNPs from the digested fish and to determine their size by MALS. The PSNPs could be easily detected by following their light scattering (LS) signal with a limit of detection of 52 μg/g fish. The AF4-MALS method could also be exploited for another type of nanoplastics in solution, namely polyethylene (PE). However, it was not possible to detect the PE particles in fish, due to the presence of an elevated LS background. Our results demonstrate that an analytical method developed for a certain type of nanoplastics may not be directly applicable to other types of nanoplastics and may require further adjustment. This work describes for the first time the detection of nanoplastics in a food matrix by AF4-MALS. Despite the current limitations, this is a promising methodology for detecting nanoplastics in food and in experimental studies (e.g., toxicity tests, uptake studies).
KeywordsNanoplastics Asymmetric flow field-flow fractionation Nanoparticles Multi-angle light scattering Enzymatic digestion
The seabass sample was kindly provided by the ECsafeSEAFOOD project (n° 311820) granted by the European Union Seventh Framework Programme (FP7/2007-2013). The authors would like to thank the Danish Veterinary and Food Administration for financial support.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 1.Hollman PCH, Bouwmeester H, Peters RJB (2013) Microplastics in aquatic food chain: sources, measurement, occurrence and potential health risks. Wageningen, RIKILT Wageningen UR (University and Research centre), RIKILT report.Google Scholar
- 5.Sundt P, Schulze P-E, Syversen F (2015) Sources of microplastic-pollution to the marine environment (Mepex report to the Norwegian Environment Agency/Miljødirektoratet, report number M-321). 86.Google Scholar
- 14.Michler GH. Electron microscopy of polymers. Berlin: Springer-Verlag; 2008.Google Scholar
- 16.Schimpf M, Caldwell K, Giddings JC. Field-flow fractionation handbook. New York: Wiley; 2000.Google Scholar
- 17.Gigault J, El Hadri H, Reynaud S, Deniau E, Grassl B. Asymmetrical flow field flow fractionation methods to characterize submicron particles: application to carbon-based aggregates and nanoplastics. Anal Bioanal Chem. 2017; https://doi.org/10.1007/s00216-017-0629-7.
- 19.Loeschner K, Navratilova J, Købler C, Mølhave K, Wagner S, von der Kammer F, et al. Detection and characterization of silver nanoparticles in chicken meat by asymmetric flow field flow fractionation with detection by conventional or single particle ICP-MS. Anal Bioanal Chem. 2013;405:8185–95. https://doi.org/10.1007/s00216-013-7228-z.CrossRefGoogle Scholar
- 21.Wagner S, Legros S, Loeschner K, Liu J, Navratilova J, Grombe R, et al. First steps towards a generic sample preparation scheme for inorganic engineered nanoparticles in a complex matrix for detection, characterization, and quantification by asymmetric flow-field flow fractionation coupled to multi-angle light scattering and. J Anal At Spectrom. 2015;30:1286–96. https://doi.org/10.1039/C4JA00471J.CrossRefGoogle Scholar