Exploring Perfluoroalkyl Substances (PFASs) in Aquatic Fauna of Lake Trasimeno (Italy): Insights from a Low-Anthropized Area.

This study investigated the concentrations and profiles of 19 perfluoroalkyl substances (PFASs) in the muscle and liver of four freshwater species from Lake Trasimeno (Italy): Anguilla anguilla (European eel), Carassius auratus (goldfish), Perca fluviatilis (European perch), and Procambarus clarkii (red swamp crayfish). In livers, the amount of PFASs ranged from 3.1 to 10 µg kg-1, significantly higher than that in muscle (0.032-1.7 µg kg-1). The predominant PFASs were perfluorooctane sulfonic acid (PFOS) and long-chain carboxylic acids (C8-C14). Short-chain compounds (C4-C5), as well as the long-chain sulfonic acids (C9-C12), were not quantified. The contamination patterns were similar among species with few differences, suggesting the influence of species-specific accumulation. The PFAS concentrations in livers were comparable among species, while in muscle, the higher values were measured in European eel, followed by goldfish, European perch, and red swamp crayfish. The levels were generally lower than those reported for fish from Northern Italian lakes and rivers. The concentrations of regulated PFASs were lower than the maximum limits set by Regulation EU 2023/915 and did not exceed the Environmental Quality Standards (PFOS in biota). This study provides the first valuable insights on PFASs in freshwater species from Lake Trasimeno.

Analytical modelling of the transport in analog filamentary conductive-metal-oxide/HfOx ReRAM devices.

The recent co-optimization of memristive technologies and programming algorithms enabled neural networks training with in-memory computing systems. In this context, novel analog filamentary conductive-metal-oxide (CMO)/HfOx redox-based resistive switching memory (ReRAM) represents a key technology. Despite device performance enhancements reported in literature, the underlying mechanism behind resistive switching is not fully understood. This work presents the first physics-based analytical model of the current transport and of the resistive switching in these devices. As a case study, analog TaOx/HfOx ReRAM devices are considered. The current transport is explained by a trap-to-trap tunneling process, and the resistive switching by a modulation of the defect density within the sub-band of the TaOx that behaves as electric field and temperature confinement layer. The local temperature and electric field distributions are derived from the solution of the electric and heat transport equations in a 3D finite element ReRAM model. The intermediate resistive states are described as a gradual modulation of the TaOx defect density, which results in a variation of its electrical conductivity. The drift-dynamics of ions during the resistive switching is analytically described, allowing the estimation of defect migration energies in the TaOx layer. Moreover, the role of the electro-thermal properties of the CMO layer is unveiled. The proposed analytical model accurately describes the experimental switching characteristic of analog TaOx/HfOx ReRAM devices, increasing the physical understanding and providing the equations necessary for circuit simulations incorporating this technology.

Analog Resistive Switching Devices for Training Deep Neural Networks with the Novel Tiki-Taka Algorithm.

A critical bottleneck for the training of large neural networks (NNs) is communication with off-chip memory. A promising mitigation effort consists of integrating crossbar arrays of analogue memories in the Back-End-Of-Line, to store the NN parameters and efficiently perform the required synaptic operations. The "Tiki-Taka" algorithm was developed to facilitate NN training in the presence of device nonidealities. However, so far, a resistive switching device exhibiting all the fundamental Tiki-Taka requirements, which are many programmable states, a centered symmetry point, and low programming noise, was not yet demonstrated. Here, a complementary metal-oxide semiconductor (CMOS)-compatible resistive random access memory (RRAM), showing more than 30 programmable states with low noise and a symmetry point with only 5% skew from the center, is presented for the first time. These results enable generalization of Tiki-Taka training from small fully connected networks to larger long-/short-term-memory types of NN.

Determination of highly polar anionic pesticides in beehive products by hydrophilic interaction liquid chromatography coupled to mass spectrometry.

The analysis of highly polar pesticides is challenging due to their unique physicochemical properties, requiring specialized chromatographic techniques for their accurate and sensitive detection. Furthermore, the high level of co-extracted polar matrix components that can co-elute with the analytes can interfere with the analysis. Consequently, there is lack of pesticide monitoring data, as the European Food Safety Authority has pointed out. This article explores the overcoming of such difficulties in the analysis of these compounds. Analytical methodologies for the extraction, clean-up, and direct determination of 11 highly polar anionic pesticides, including glyphosate, glufosinate, ethephon, fosetyl-aluminium, and their related metabolites in complex food matrices such as honey and pollen by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry were successfully developed and validated. Solid-phase extraction and micro-solid-phase extraction employing strong anion exchange (SAX) cartridges were implemented for clean-up. The automation and miniaturization of SAX clean-up for these compounds were achieved for the first time. For method validation, SANTE/11312/2021 guideline was followed. Recoveries were between 70 and 120%, with RSDs below 20%. Limits of quantitation ranged from 0.005 to 0.020 mg kg-1. Linearity was evaluated from 0.002 to 0.200 mg kg-1. Matrix effects were assessed, showing medium to low signal suppression for most compounds. AMPA and glufosinate presented the highest signal suppression, but it was reduced after SAX clean-up. Analysis of real honey and pollen samples revealed the occurrence of the studied compounds in beehive products and showed the applicability of the validated methodologies for routine control of these complex samples.

Brominated flame retardants (PBDEs and HBCDs) and perfluoroalkyl substances (PFASs) in wild boars (Sus scrofa) from Central Italy.

Twenty-six samples of wild boar liver and muscle from the Central Apennine Mountain (Italy) were analysed for 19 perfluoro-alkyl substances (PFASs), 10 polybrominated diphenylethers (PBDEs) and 3 hexabromocyclododecanes (HBCDs). All samples were analysed by gas chromatography-tandem mass spectrometry for PBDEs and liquid chromatography-tandem mass spectrometry for PFASs and HBCDs, using an in-house developed analytical procedure. The brominated flame retardants (BFR) levels in livers were negligible: Σ10PBDEs reached a maximum value of 0.079 µg/kg, whereas HBCDs were not quantified in almost all of the samples analysed. BFR concentrations in muscles were higher, but not significantly therefore, for Σ10PBDEs lower bound, a mean value of 0.045 µg/kg (0.005-0.155 µg/kg range) was measured, while α-HBCD was quantified with a maximum of 0.084 µg/kg in 9 of the samples. Only two muscles contained all 3 HBCD isomers at concentrations of approximately 0.200 µg/kg. Σ19PFAS in the 26 wild boar livers was in the range 31.9-228 µg/kg, with a mean value of 87.7 µg/kg, reaching levels significantly higher than in muscles, which exhibited a mean concentration of 3.08 µg/kg (0.59-9.12 µg/kg range). Perfluorooctanesulfonic acid (PFOS) was the most prevalent compound in all liver samples, accounting for more than half of the total PFASs contamination, confirming that the liver is the primary target organ for PFOS exposure Perfluorotridecanoic acid (PFTrDA), which accounts for 25-30-% of the total contamination, was the most abundant compound in the muscle, followed by PFOS. The estimated daily intake (EDIs) of BFRs remained below the estimated chronic human daily dietary intake (Dr,h) defined from European Food Safety Authority (EFSA). Furthermore, the exposure to PFASs in muscle was 7.7 times lower than the EFSA's tolerable daily intake (TDI). In contrast, exposure due to liver consumption was significant: the EDI exceeded the EFSA's 2020 TDI by approximately 7 times.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs): An optimized LC-MS/MS procedure for feed analysis.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are extremely stable highly fluorinated aliphatic compounds, widely used in chemical and industrial applications since 1950s. They are ubiquitously detected in the environment and diet is the main route for human exposure. To ensure human safety, it is necessary to follow the whole food production chain, including animal feed. Still PFASs are not regulated as undesirable substances in feed, although several studies have shown they can be transferred from feed to livestock and thereafter to food. This paper describes the development, optimization and the full validation of a sensitive and reliable analytical protocol enabling the quantification of 19 PFASs in animal feeds by liquid chromatography - mass spectrometry (LC-MS/MS). The method was optimized, assessing the possible matrix interferences, and submitted to comprehensive validation (55 independent spiking experiments). Validation experiments were conducted on blank fish feed samples (natural levels of PFASs < 0.10 ng g-1) spiked at five different concentrations (0.10, 0.50, 1.0, 5.0 and 10 ng g-1). Apparent recoveries (R%) were generally between 88 and 111%; R% < 80% were obtained only at the lower validation levels for those molecules not having the corresponding labelled analogues. Relative standard deviations in repeatability conditions (RSDr) and within-lab reproducibility conditions (RSDwR) were lower or equal to 11% and 22% respectively. Limits of quantification were set for most of the analytes at 0.10 ng g-1 (LOQs) and verified with repeated analysis on fortified samples (0.10 ng g-1). Limits of detection (LODs) were calculated as 1/3 LOQ. Finally the method was applied to 23 feed samples of different type (compound feed, vegetable feed material, complementary feed, pre-mixture and mineral feed) and all of them did not show PFAS above LOQ.

Risk Characterization and Benefit-Risk Assessment of Brominated Flame Retardant in Commercially Exploited Freshwater Fishes and Crayfish of Lake Trasimeno, Italy.

Among brominated flame retardants (BFRs), polybrominateddiphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) were the most widely used in past decades. BFRs not being chemically bonded to polymers means they can easily leach from the products into the environment and bioaccumulate. Humans are exposed to flame retardants mainly through food consumption, especially fish and fish products. In the present study, the occurrence of PBDEs and HBCDs in freshwater fishes and crayfish from Lake Trasimeno (Umbria region, central Italy) was assessed according to monitoring plans recommended by European competent authorities. The dietary exposure of the central Italian population to such molecules was calculated, and the risk characterization and the benefit-risk evaluation were also assessed. A total of 90 samples were analyzed by means of gas and liquid chromatography associated with triple quadrupole mass spectroscopy. A total of 51% of samples were found positive for at least one of the congeners; the most frequently found molecule was BDE-47. The data on dietary exposure ranged from 0.138 to 1.113 pg/kg body weight/day for ∑PBDE and from 0.805 to 0.868 pg/kg body weight/day for ∑HBCD. The data show no health risks for the central Italian population consuming freshwater fish products from Lake Trasimeno in relation to exposure to PBDE and HBCD.

Heavy metal spatial and temporal trends (2008-2018) in clams and mussel from Adriatic Sea (Italy): Possible definition of forecasting models.

In 2008-2018, 1458 georeferenced samples of clams and 343 of mussels were harvested in Italy from classified areas along Marche coast and analyzed within food-safety monitoring plans. Pb, Cd, V, Ni, Cr, and As median levels (mg kg-1) were 0.09, 0.08, 0.29, 0.77, 0.35, and 2.35 in clams and 0.16, 0.15, 0.46, 0.48, 0.25, and 3.34 in mussels. The reported levels were comparable with the published ones, and Hg always fell below LOQ (0.025 mg kg-1). Pb and Cd datasets, based on quarterly results, show a decreasing trend in clams and constant baseline value for mussels. Time-trends and forecasting models represent an asset to predict emerging food safety/security risks. The metal levels in mussels and clams from the same area allow environmental safety assessment and thus enable the evaluation of contaminants in both water column and sediment. Monitoring of elements that are not regulated may help in preserving food and environmental safety.

BFRs (PBDEs and HBCDs) in freshwater species from Lake Trasimeno (Italy): The singular case of HBCDs in red swamp crayfish.

Eighty-six samples belonging to five different species (crucian carp, Carassius carassius; European perch, Perca fluviatilis; tench, Tinca tinca; eel, Anguilla anguilla; red swamp crayfish, Procambarus clarkii) collected from Lake Trasimeno (Italy) were analyzed to assess polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) contamination. The Trasimeno is the largest Italian peninsular lake located in Umbria (Central Italy), in a rural area with low anthropogenic impact. All the samples were analyzed by an in-house developed analytical procedure involving a single sample preparation with dual detection: Gas- and Liquid-Chromatography coupled to tandem Mass Spectrometry (GC-MS/MS for PBDEs and LC-MS/MS for HBCDs). BFRs levels in crucian carp, tench and European perch were negligible and mostly below quantification limits (LOQs). In eel, the species with the higher fat content, PBDE sum (15 congeners) ranged from 0.269 to 0.916 ng/g w.w. BDE-47, -100 and -154 accounted for roughly 57%, 16% and 11% of the PBDE sum, respectively, while BDE-99 (usually one of the most abundant congeners in biota), only for 3%. HBCDs (sum of α-, ß-, γ-isomers) were found between 0.157 and 1.14 ng/g w.w. with α- as predominant isomer (92% of the sum), followed by γ- (5%) and ß- (2%). Peculiar was the contamination in red swamp crayfish characterized by negligible PBDEs and very high HBCDs levels with a singular contamination pattern. In female pools (n = 9) the mean HBCDs sum was 0.150 ng/g w.w., while in males higher concentrations were measured (mean = 2.77 ng/g w.w.). A significant correlation seems to exist between the contamination level and the seasonal cycle only in male crayfish. Interestingly, among the HBCDs, the γ-isomer was the highest (67% of the total) while α- contributes only for 20%.

Single sample preparation for brominated flame retardants in fish and shellfish with dual detection: GC-MS/MS (PBDEs) and LC-MS/MS (HBCDs).

An analytical method for the simultaneous determination of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in fish, shellfish and muscle of terrestrial animals was developed as an extension of a previously validated method for PBDE analysis. A single sample preparation based on QuEChERS-like extraction and a two-step clean-up, followed by a dual instrumental detection, was implemented. GC-MS/MS was used for PBDEs and LC-MS/MS for HBCDs. The method allows the quantification of fifteen PBDEs (28, 47, 49, 66, 77, 85, 99, 100, 138, 153, 154, 183, 197, 206, 209) and three HBCD isomers (α, ß and γ), reaching 10 pg/g LOQs for all the analytes except BDE 206 and 209 (100 pg/g LOQ). The validated method was applied to the analysis of 12 fish and shellfish species (sole, spiny dogfish, smooth-hound, mackerel, swordfish, grey mullet, cod, anchovy, red mullet, Atlantic horse mackerel, tuna fish and mussel) collected in central Italian markets accounting for a total of 44 samples. Generally, ΣPBDEs showed higher concentration than ΣHBCDs except in the case of mussels in which ΣHBCDs > ΣPBDEs. Cod and smooth-hound are the least contaminated species among those analysed in the present study, whereas the highest brominated flame retardant (BFR) levels were found in spiny dogfish samples. The measured contamination levels were generally comparable to or lower than those already published in European studies. Literature data for HBCDs in European fish and shellfish were hard to find; therefore, PBDE and HBCD levels were also compared with European Environmental Quality Standard (EQS) in biota (Directive 2013/39/EU). EQSs for HBCDs are six orders of magnitude higher than those for PBDEs; therefore, while no exceedance was observed for the first, almost all the samples analysed for PBDEs were above EQSs. The presented preliminary data on PBDEs and HBCDs are among the first published in marine fish and shellfish commercialised in Central Italy. Graphical abstrac.