Extraction and quantification of metal-containing nanoparticles in marine shellfish based on single particle inductively coupled plasma-mass spectrometry technique.

Quantitative characterization of nanoparticles (NPs) in marine shellfish is critical to understanding the risks of bio-accumulation. Based on single particle (sp)ICP-MS and electron microscopy, a standardized protocol was developed to extract Ag, Au, and indigenous Ti-containing NPs from mussels. The optimal parameters are: dry sample extraction with tetramethylammonium hydroxide (TMAH), 5% (v/v) final concentration of TMAH, extraction at 25 ℃ for 12 h, and separation by centrifugation (3000 rpm for 5 min). The particle number recoveries of spiked Ag and Au NPs were 88 ± 0.9% and 95 ± 1.1%, respectively, while Ti-containing NPs had a particle number concentration of 8.2 × 10 particles/mg and an average size of 70 nm in tested mussels. Furthermore, titanium oxide NPs, including rutile, anatase, and Magnéli phases (TiO) were found ubiquitously in 10 shellfish based on the optimal method. The particle number concentrations and average sizes of the Ti-containing NPs were 2.1 × 10-8.4 × 10 particles/mg and 70-80 nm, respectively. These Ti-containing NPs, such as TiO, accounted for about half of the Ti mass in shellfish, indicating that marine shellfish may be a significant sink for Ti-containing NPs.