Chemical Characterization and Quantification of Silver Nanoparticles (Ag-NPs) and Dissolved Ag in Seafood by Single Particle ICP-MS: Assessment of Dietary Exposure

Abstract

This study provides a first insight on the chemical characterization and quantification of silver nanoparticles (AgNPs) and dissolved Ag in processed canned seafood products, where food-grade edible silver (E174) is not intentionally added nor is the nanoparticle contained in the food contact material. The aim was to evaluate the bioaccumulation potential of AgNPs and to contribute to the assessment of AgNPs and ionic Ag human dietary intake from processed seafood. It is known how seafood, and in particular pelagic fish, is a precious nutritional source of unsaturated fatty acids, protein, and different micronutrients. Nevertheless, it may cause possible health problems due to the intake of toxic compounds coming from environmental pollution. Among emerging contaminants, AgNPs are widely applied in several fields such as biomedicine, pharmaceutical, food industry, health care, drug-gene delivery, environmental study, water treatments, and many others, although its primary application is in accordance with its antimicrobial property. As a consequence, AgNPs are discharged into the aquatic environment, where the colloidal stability of these NPs is altered by chemical and physical environmental parameters. Its toxicity was demonstrated in in-vitro and in-vivo studies, although some findings are controversial because toxicity depends by several factors such as size, concentration, chemical composition, surface charge, Ag+ ions released, and hydrophobicity. The new emerging technique called single-particle inductively coupled plasma mass spectrometry (spICP-MS) was applied, which allows the determination of nanoparticle number-based concentration and size distribution, as well as the dissolved element. Our findings highlighted comparable mean sizes across all species analysed, although AgNPs concentrations partly follow a trophic level-dependent trend. The low mean size detected could be of human health concern, since, smaller is the diameter higher is the toxicity. Dietary intake from a meal calculated for adults and children seems to be very low. Although seafood consumption represents only a small part of the human total diet, our findings represent a first important step to understand the AgNPs dietary exposure of the human population. Further studies are needed to characterize and quantify AgNPs in a large number of food items, both processing and not, and where AgNPs are added at the industrial level. They will provide a realistic exposure assessment, useful to understand if AgNPs toxicity levels observed in literature are close to those estimable through food consumption and implement data useful for risk assessors in developing AgNPs provisional tolerable daily intake.

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…8.2.7 Fish and seafood. Grasso et al 135,136 published 2 papers investigating TiO 2 and Ag nanoparticles in seafood. Multiple samples of canned tuna, mackerel, anchovies and clams were obtained from the local market and digested under alkaline conditions using TMAH, to preserve the integrity of the particles.…”

“…The sizes of NPs and flakes tended to be slightly larger in food products compared to the actual additive. Grasso et al 135 used spICP-MS to determine the number and size of AgNPs in canned tuna, mackerel, anchovy and clam in order to assess discharge of NPs into the aquatic environment and the implications for human health. Procedures for extraction of NPs and digestion for total Ag measurement were validated and values determined for NP size, diameter, number, total Ag and Ag in NPs.…”

Atomic Spectrometry Update: review of advances in elemental speciation

“…A survey has been undertaken for the Ag I and Ag NP content of canned seafood samples, anchovy, clam, mackerel and tuna, available on the Italian market. 170 The analytes of interest were extracted by alkaline hydrolysis, TMAH for 24 hours with initial UAE for 30 minutes at 37 °C followed by dilution with 1% TMAH and analysis by sNP-ICP-MS. The LOD of the method, evaluated using procedural blanks, was 1.5 × 10 3 particles per mL, which equated to 3.3 × 10 5 particles per g after the sample mass and TMAH volumes used were accounted for.…”

Proteomics reveals multiple effects of titanium dioxide and silver nanoparticles in the metabolism of turbot, Scophthalmus maximus

“…Another possible transformation of NPs that could occur is the dissolution of them after their uptake (Abbas et al, 2020). In fact, several reports have shown that Ag NPs can undergo either dissolution or sulfidation, or both transformation when they are uptaken by cells/organisms (Moore et al, 2015;Yue et al, 2017;Grasso et al, 2021;Khan et al, 2019). Distinct accumulation patterns to NPs exposure are expected in each organ, which can be associated with the contributions of different organs to the detoxification, excretion or uptake of exogenous substances (Bartucci et al, 2020).…”