Effect of TiO2 Nanoparticle on Bioaccumulation of ndl-PCBs in Mediterranean Mussels (Mitilus galloprovincialis)

The interaction of nanomaterials with pollutants in the marine environment might alter bioavailability, as well as toxicity, of both nanomaterials and pollutants, representing a risk, not only for marine organisms, but also for consumers through the marine food chain.The aim of this study was to evaluate the effect of titanium dioxide nanoparticles (TiO2NPs) in terms of bioaccumulation and toxicity on Mediterranean mussels (Mytilus galloprovincialis) exposed to six-indicator non-dioxin-like polychlorinated biphenyls (ndl-PCBs). Mussels were exposed to ndl-PCBs (20 µg/mL) (groups 3–4) or to a combination of ndl-PCBs (20 µg/mL) and TiO2NPs (100 µg/mL) (groups 5–6) for four consecutive days. TiO2NPs was detected in groups 5–6 (3247 ± 567 and 1620 ± 223 µg/kg respectively), but their presence did not affect ndl-PCBs bioaccumulation in mussels. In fact, in groups 3–4, the concentration of ndl-PCBs (ranging from 3818.4 ± 166.0–10,176 ± 664.3 µg/kg and 2712.7 ± 36.1–9498.0 ± 794.1 µg/kg respectively) was not statistically different from that of groups 5–6 (3048.6 ± 24.0–14,635.9 ± 1029.3 and 5726.0 ± 571.0–9931.2 ± 700.3 µg/kg respectively). Histological analyses showed alterations to the structure of the gill tissue with respect to the control groups, with more severe and diffuse dilatation of the central hemolymphatic vessels of the gill lamellae in groups 5–6 (treated with TiO2NPs and ndl-PCBs concurrently) compared to groups 3–4 (ndl-PCBs only). Finally, in mussels submitted to a seven-day depuration process, most TiO2NPs were eliminated, and NPs had a synergistic effect on ndl-PCBs elimination; as a matter of fact, in groups 5–6, the percentage of concentration was statically inferior to the one observed in groups 3–4. In any case, consumers might be exposed to TiO2NPs and ndl-PCBs (both concurrently and separately) if edible mussels, harvested in a contaminated environment, are consumed without a proper depuration process.

Fast and Sensitive Analysis of Short- and Long-Chain Perfluoroalkyl Substances in Foods of Animal Origin

The availability of sensitive analytical methods to detect per- and polyfluoroalkyl substances (PFASs) in food of animal origin is fundamental for monitoring programs to collect data useful for improving risk assessment strategies. The present study aimed to develop and validate a fast and sensitive method for determining short and long-chain PFASs in meat (bovine, fish, and swine muscle), bovine liver, hen eggs, and cow’s milk to be easily applicable in routine analysis of food. A QuEChERS extraction and clean-up method in combination with liquid chromatography coupled to mass spectrometry (LC-MSMS) were used. The method resulted in good linearity (Pearson’s R > 0.99), low limits of detection (7.78−16.35 ng/kg, 8.26−34.01 ng/kg, 6.70−33.65 ng/kg, and 5.92−19.07 ng/kg for milk, liver, egg, and muscle, respectively), and appropriate limits of quantification (50 ng/kg for all compounds except for GenX and C6O4, where the limits of quantification were 100 ng/kg). Trueness and precision for all the tested levels met the acceptability criteria of 80−120% and ≤20%, respectively, regardless of the analyzed matrix. As to measurement uncertainty, it was <50% for all compound/matrix combinations. These results demonstrate the selectivity and sensitivity of the method for simultaneous trace detection and quantification of 14 PFASs in foods of animal origin, verified through the analysis of 63 food samples.

Rapid, novel screening of toxicants in poison baits, and autopsy specimens by ambient mass spectrometry

Animal poisoning and dissemination of baits in the environment have public health and ethological implications, which can be followed by criminal sanctions for those responsible. The reference methods for the analysis of suspect baits and autopsy specimens are founded on chromatographic-based techniques. They are extremely robust and sensitive, but also very expensive and laborious. For this reason, we developed an ambient mass spectrometry (AMS) method able to screen for 40 toxicants including carbamates, organophosphate and chlorinated pesticides, coumarins, metaldehyde, and strychnine. Spiked samples were firstly purified and extracted by dispersive solid phase extraction (QuEChERS) and then analyzed by direct analysis in real time high-resolution mass spectrometry (DART-HRMS). To verify the performance of this new approach, 115 authentic baits (n = 59) and necropsy specimens (gastrointestinal content and liver, n = 56) were assessed by the official reference methods and combined QuEChERS-DART-HRMS. The agreement between the results allowed evaluation of the performances of the new screening method for a variety of analytes and calculation of the resultant statistical indicators (the new method had overall accuracy 89.57%, sensitivity of 88.24%, and a specificity of 91.49%). Taking into account only the baits, 96.61% of overall accuracy was achieved with 57/59 samples correctly identified (statistical sensitivity 97.50%, statistical specificity 94.74%). Successful identification of the bitter compound, denatonium benzoate, in all the samples that contained rodenticides (28/28) was also achieved. We believe initial screening of suspect poison baits could guide the choice of reference confirmatory methods, reduce the load in official laboratories, and help the early stages of investigations into cases of animal poisoning.

Investigation of levels of perfluoroalkyl substances in freshwater fishes collected in a contaminated area of Veneto Region, Italy

The bioaccumulation of 12 perfluoroalkyl substances (PFASs) in 107 freshwater fishes collected during 2017 in waterbodies of a contaminated area in Veneto Region (Italy) was evaluated. The contamination had been previously ascribed to a fluorochemical manufacturing plant that discharged mainly perfluorooctanoic acid (PFOA), among other PFASs, into the surrounding environment. Perfluorooctane sulfonate (PFOS) was the most abundant compound, detected in almost 99% of the fish with an average concentration of 9.23 µg/kg wet weight (w/w). Other detected compounds were perfluoroundecanoic acid (PFUnA) (98%, 0.55 µg/kg w/w), perfluorodecanoic acid (PFDA) (98%, 2.87 µg/kg w/w), perfluorododecanoic acid (PFDoA) (93%, 1.51 µg/kg w/w), and PFOA (79%, 0.33 µg/kg w/w). Bioaccumulation of PFASs was species related, with Italian barbel being the most contaminated, followed by chub, wels catfish, and carp, reflecting animals' habitat use and feeding behavior. A significant negative linear relation between PFAS concentration and fish weight was observed no matter the considered species, with smaller fish having proportionally higher bioaccumulation. PFOS concentrations were strongly correlated with the concentrations of other PFASs, suggesting a similar source of contamination or a contamination from ubiquitous sources. Correlation analysis showed PFOA likely originated from a separated source, unlinked to other PFASs. Although the fishes studied are not usually consumed by local people, with the likely exception of freshwater anglers (and relatives), their consumption has been banned by Veneto Authority since the time this study was conducted. In fact, the study suggests that a medium/high consumption frequency (superior to 1 portion per month) of fish from the investigated area might result in a high exposure to PFASs.

Fast and simultaneous analysis of carbamate pesticides and anticoagulant rodenticides used in suspected cases of animal poisoning

Carbamate pesticides (CBs) are reported as one of the main causes of intentional or accidental poisoning of animals. Anticoagulant rodenticides (ARs) form the main class of poisons implicated in analyzed poisoned baits. These two groups of pesticide compounds include multiple substances, and thus, the development of a simple and rapid multiclass/multiresidue analytical method for simultaneous identification of both toxicant classes should be a useful strategy for analytical laboratories to reduce analysis time and cost. The present study aimed to elaborate and validate a rapid method to simultaneously determine 11 CBs and 8 ARs in samples of real matrices (bait, stomach content, and liver) from suspected animal poisoning cases. QuEChERS sample treatment and liquid chromatography coupled to hybrid high resolution mass spectrometry were used. The method resulted in good linearity (R2 ≥ 0.98) for all compounds, recovery was between 70% and 120% for CBs and 40-90% for ARs, and precision was ≤ 20% for all compounds. The method was successfully applied to the analysis of 871 real samples originating from suspected cases of animal poisoning, collected from April 2019 to October 2020. Furthermore, full scan dependent data acquisition allowed qualitative retrospective data analysis of an additional 15 compounds outside the scope of the method to be performed; these compounds could potentially be involved in unresolved poisoning cases.

LC-HRMS/MS for the simultaneous determination of four allergens in fish and swine food products

The inclusion on the label of packed foods of any ingredient or technological adjuvant causing allergies is required by EU food legislation. In this study a targeted proteomics method for detecting four allergens in animal-derived food matrices was developed. Liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-HRMS/MS) was used to select marker peptides from four allergens and develop a quantitative method able to simultaneously detect the presence of milk, egg, crustaceans and soy. The method was validated on fish or swine processed food products contaminated at 5 μg g^-1 for milk and egg and 10 μg g^-1 for soy and crustaceans. The method was tested by analyzing commercial food products with high protein content and was compared to the ELISA technique. Our results indicated the presence of soy not reported on the food label of some products, pointing out the need for efficient controls to protect allergic consumers.

Bioaccumulation and in vivo formation of titanium dioxide nanoparticles in edible mussels

The aim of this study was to evaluate the bioaccumulation of titanium dioxide nanoparticles (TiO2NPs) in edible mussels bred in polluted artificial seawater. An in vivo study was conducted by exposing mussels to different concentrations of TiO2NPs (0.25 mg/L and 2.5 mg/L) or ionic titanium (1.6 mg/L) for 4 days. Inductively coupled plasma mass spectrometry (ICP-MS) showed titanium presence in all groups proportional to exposure levels (concentration range: 209-1119 µg/kg). Single particle ICP-MS revealed NPs in both TiO2NP treated mussels (concentration range: 231-1778 µg/kg) and in ionic titanium treated mussels (concentration 1574 µg/kg), suggesting potential nanoparticle formation in vivo. These results were confirmed by transmission electron microscopy with energy dispersive X-ray detection. Nonetheless, mussels eliminated more than 70% of the TiO2NPs after 3 days' depuration. These results show the potential for consumer exposure to TiO2NPs when contaminated mussels are consumed without a proper depuration process.