Distribution of fluorochemicals in the compartments of dispersed systems

National audienc

Quantification of light Polycyclic Aromatic Hydrocarbons in seafood samples using on-line Dynamic HeadSpace extraction, ThermoDesorption, Gas Chromatography tandem Mass Spectrometry, based on an isotope dilution approach

The aim of our work was to develop an analytical strategy to quantify naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene in fish products by on-line dynamic headspace extraction, followed by thermodesorption injection and gas chromatography analysis coupled with tandem mass spectrometry using electron ionization mode (DHS-TD-GC-EI-MS/MS). The developed protocol used 1 g of freeze-dried or oil sample supplemented with perdeuterated light PAHs. The sample was heated at [90 - 100°C], the headspace of the sample was swept by nitrogen and the trapping of the PAHs was carried out on a Tenax-type adsorbent placed at 25°C. Analytes were thermodesorbed at 300°C from the dried adsorbant and then cryofocused on a cooled injection system (CIS) at ¬25°C before injection (12°C s−1 up to 300°C). The chromatographic separation of PAHs was carried out on a 5-MS type column (30 m × 0.25 mm, 0.25 μm) and the acquisition of the signals was performed in SRM following the transitions, involving the loss of one or two hydrogen atoms from the molecular ion. In view of the principle of extraction, the calibration curve was performed on a representative matrix or using the standard addition method. Quantification limits were determined between 0.01 and 0.6 ng g−1 of matrix from the method blank results. The method was validated by a series of multi-level supplemented matrix assays and by the analysis of a reference material from an inter-laboratory test (mussels, IAEA-432). The average of the expanded measurement uncertainty was from 9 to 44% for the four lightest PAHs, except for fluorene when the sample incubation was set at 90°C. Occurrence measurements were performed on almost two hundred samples of molluscs, echinoderms and fish. The results have shown a quantification frequency greater than 66% for naphthalene and fluorene, at concentrations below a few ng g−1 of dry matter of fishery products. With this methodology, the light PAHs occurrence can now be measured in a wider range of foodstuffs in order to better characterize their contamination trends and the associated risk simultaneously.

Legacy and alternative halogenated flame retardants in Lake Geneva fish

Legacy (i.e., polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD)) and alternative halogenated flame retardants (HFRs) were analyzed in 31 whole fish samples from Lake Geneva in 2018. Two fish species, namely, the burbot (Lota lota) and the roach (Rutilus rutilus), were selected, hypothetically representing different habitats, feeding behaviors, and different metabolic capacities. Roach (N = 20) and burbot (N = 11) displayed similar size and mass, but the latter species was overall leaner than the former. The sum of individual PBDE concentrations (0.54-9.86 ng g(-1)wet weight (ww)) was similar in both species, but the respective molecular profiles suggested contrasted metabolic capacities. HBCDD sum of isomer concentrations ranged from non-detected to 3.477 ng g(-1)(ww), also similar in both species. Both PBDEs and HBCDD levels were far below the threshold that indicates a risk to fish predators. Referring to previous surveys, which involved a wider range of species, PBDE concentrations have declined or are stable. HBCDD concentrations remained low, despite the PBDE ban, which could have fostered the consumption of other HFRs. The occurrence of alternative HFRs was also low for most compounds analyzed. Only dechloranes and decabromodiphenyl ethane (DBDPE) had detection rates above 50%. Dechloranes spanned a concentration range between 5 and 10 times the quantification limits (0.002 to 0.005 ng g(-1)wet weight), lower than DBDPE (< 0.005 to 2.89 ng g(-1)wet weight). Quality standards targeting biota are currently missing for these emerging chemicals

Contamination of food by fluorinated surfactants - Distribution in emulsions and impact on the interfacial protein behaviour

International audiencePerfluorooctanesulphonic acid (PFOS) and perfluorooctanoic acid (PFOA) are the final products of degradation of numerous fluorochemicals, intensively used in industry. Due to their high stability and low level of biodegradability, they remain in the environment. Their occurrence in milk constitutes one of the numerous initial steps of contamination of many manufactured food products. We contributed to the understanding of the food contamination in analysing the distribution of PFOS and PFOA in food model emulsions. Emulsions stabilised by whey protein isolates were prepared from either contaminated aqueous phase or contaminated sunflower seed oil phase and homogenised at high pressures. Aqueous and creamed phases of emulsions were separated to evaluate the distribution of PFOS and PFOA between these two phases using a combination of liquid chromatography and mass spectrometry. PFOS and PFOA, initially present in water, migrate in the creamed phase due to their bindings with ! proteins that cover the oil-water interface of oil droplets. PFOS may also be present at interfaces due to its hydrophobicity. PFOS and PFOA bound to proteins moreover modified the interfacial behaviour of proteins at model air-water interfaces in proportions depending on the concentration and the head group of the perfluorinated surfactants

Food contact material for baking: a review on associated chemical risks and technological issues

This article presents an overview on product contact surfaces (PCS) used for baking supports, with a focus on associated neoformed and exogenous contaminants related to these PCSs in the case of baking. Exogenous contaminants are usually brought into the product from the surface contact material of the baking support, and in particular, from antistick coatings (ASC). Due to multiple thermal treatments, the performance of ASCs evolve during ageing, resulting in sticking problems. In addition, there is no European regulation in force to track associated chemical risks. Two main types of ASC material are used: perfluorinated and silicone based ASC. Sticking of bakery products during baking is linked to various aspects such as recipe, baking temperature, the use (or not) of antistick fluids, etc. For instance, silicone coatings are preferred to perfluorinated coatings for yellow dough. Some products, such as biscuits, can be baked directly on steel. A limited amount of literature exists on the risk of chemical transfer from either fluorinated or silicone based coatings to the food. Highly sensitive measurement methods based on liquid chromatograpy coupled to tandem mass spectometry (LC-MS/MS) and/or liquid chromatography-high resolution mass spectrometry (LC-HRMS) have been used for the determination of 13 perfluorinated compounds (including perfluorooctane sulfonate anion (PFOS) and perfluorooctanoic acid (PFOA) in water and pancakes cooked in contact with ASC. Preliminary results (not shown) indicated that contamination was below the regulation threshold when using new cookware equipment (frying pan). Two other PCSs used in baking, aluminium and baking paper, and their associated chemical risks are discussed. Neoformed contaminants are usually due to reactions between inoffensive precursors, which result from the interaction between these precursors and the matrix. The impact of the thermal treatment combined with the evolution of other physical parameters (e.g., moisture, pH, etc.) may result in the formation of neoformed contaminants. The case of the Maillard reaction compounds (MRCs) and of the 3-chloro-1,2-propanediol (3-MCPD) esters and the impact of the pH on those contaminants is discussed. Finally, the technological problem of sticking seems to be closely linked to the condition of the product contact surface, and thus indirectly linked to a higher risk of transfer of exogenous contaminants into the product. Therefore, it appears advisible to develop tools and protocols to assess the condition of baking support undergoing multiple thermal cycles for the benefit of the industry and of the health of consumers.JRC.I.1-Chemical Assessment and Testin

Polycyclic aromatic hydrocarbons: bees, honey and pollen as sentinels for environmental chemical contaminants.

International audienceThree beehive matrices, sampled in six different apiaries from West France, were analyzed for the presence of four polycyclic aromatic hydrocarbons (PAH4: benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene and chrysene). Samples were collected during four different periods in both 2008 and 2009. Honey samples showed the lowest levels of PAH4 contamination (min=0.03 μg kg(-1); max=5.80 μg kg(-1); mean=0.82 μg kg(-1); Sd=1.17). Bee samples exhibited higher levels of PAH4 contamination (min=0.32 μg kg(-1); max=73.83 μg kg(-1); mean=7.03 μg kg(-1); Sd=17.83) with a great dispersion of the concentrations due to four main events of high concentrations. Pollen samples showed only one major episode with the highest PAH4 concentration found (min=0.33 μg kg(-1); max=129.41 μg kg(-1); mean=7.10 μg kg(-1); Sd=22.28). The PAH4 concentrations found were significantly influenced by the landscape context for all beehive samples

Tissue Uptake, Distribution, and Elimination of Perfluoroalkyl Substances in Juvenile Perch through Perfluorooctane Sulfonamidoethanol Based Phosphate Diester Dietary Exposure

Perfluorooctane sulfonamidoethanol based phosphate diester (SAmPAP) is a potential perfluorooctanesulfonate (PFOS) precursor. To examine whether SAmPAP exposure would result in fish contamination by perfluoroalkyl and polyfluoroalkyl substances (PFASs), juvenile Eurasian perch were dietarily exposed to this compound (dosed group) or exposed to the same tank water but fed control feed (control group). SAmPAP and metabolites were monitored in the muscle, liver, and serum during the 45-day exposure phase and 35-day depuration phase. SAmPAP was only detected in the dosed group and the absorption efficiency (0.04–2.25%) was very low, possibly related to its low bioavailability in the gastrointestinal tract, steric constraints in crossing biological membranes, and clearing by enterohepatic circulation. Although SAmPAP was biotransformed and eliminated at a slow rate (<i>t</i>_1/2 > 18 days), its biomagnification factor was low. The observed metabolites in fish were <i>N</i>-ethyl perfluorooctane sulfonamidoacetic acid, perfluorooctane sulfonamidoacetic acid, perfluorooctane sulfonamide, and PFOS. Considering that SAmPAP was the only source of PFASs in the tanks, the occurrence of metabolites indicates that SAmPAP could be biotransformed in fish and contribute to PFOS bioaccumulation. However, levels of metabolites were not significantly different in the dosed and control groups, indicating that metabolite excretion followed by re-exposure to these metabolites from water was the main uptake route