Validation of a Method for Surveillance of Nanoparticles in Mussels Using Single-Particle Inductively Coupled Plasma-Mass Spectrometry

Background: Determining the concentration of nanoparticles in marine organisms is important for evaluating their environmental impact and to assess potential food safety risks to human health.

Objective: The current work aimed at developing an in-house method based on single particle inductively coupled plasma mass spectrometry suitable for surveillance of nanoparticles in mussels.

Method: A new low-cost and simple protease mixture was utilized for sample digestion, and a novel open-source data processing was used, establishing detection limits on a statistical basis using false positive and false negative probabilities. The method was validated for 30 and 60 nm gold nanoparticles spiked to mussels as a proxy for seafood.

Results: Recoveries were 76-77% for particle mass concentration and 94-101% for particle number concentration. Intermediate precision was 8-9% for particle mass concentration and 7-8% for particle number concentration. Detection limits for size was 18 nm and for concentration 1.7 ng/g and 4.2 x 10⁵ particles/g mussel tissue.

Conclusion: The performance characteristics of the method were satisfying compared with numeric Codex criteria. Further, the method was applied to titanium-, chromium- and copper-based particles in mussels.

Highlights: The method demonstrates a new practical and cost-effective sample treatment and streamlined, transparent and reproducible data treatment for the routine surveillance of NPs in mussels.