A new method for determining PFASs by UHPLC-HRMS (Q-Orbitrap): Application to PFAS analysis of organic and conventional eggs sold in Italy.

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous environmental pollutants with the ability to uptake to food and feed. Among food, fish, fruits and eggs are considered as major contributors to human dietary exposure. A new method was developed and validated for the simultaneous determination of 18 PFASs in eggs using isotope dilution followed by ultrahigh performance liquid chromatography coupled to high resolution mass spectrometry. The analysis of 132 samples (organic, barn and caged eggs) was performed. Levels were always close to the detection limits and no significant difference emerged among the 3 groups. The highest PFAS concentration in eggs was used to estimate the dietary exposure of different Italian population groups. As expected, children were more highly exposed than adults due to lower body weight. This data suggests that the recent tolerable weekly intake of 4.4 ng kg-1b.w. could be exceeded when the cumulative intake arising from other food products is considered.

Brominated and chlorinated contaminants in food (PCDD/Fs, PCBs, PBDD/Fs PBDEs): Simultaneous determination and occurrence in Italian produce.

Validated methodology for the simultaneous determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs) in foods of animal origin is presented. Method performance indicators were equivalent or better than those required for the control of EU regulated (EU, 2017/644) PCDD/F and PCB congeners in these foods, and for risk assessment through dietary intake. The method uses a high (>90%) proportion of 13Carbon-labelled surrogates for internal standardisation combined with high resolution mass spectrometry that allow accurate quantitation, and this was confirmed by multiple successful participations in proficiency testing for PCDD/Fs, PCBs and PBDEs in food. The same validation and method performance requirements as used for PCDD/Fs were followed for PBDD/Fs. The analysis of a range of food samples (eggs, milk, fish, shellfish, pork, beef and poultry), showed the occurrence of all four classes of contaminants at varying concentration ranges. In general, PCBs were the most prominent contaminant, both, in terms of dioxin-like toxicity, as well as in the occurrence of non-dioxin-like congeners, an observation that concurs with those made in other studies on Italian foods. The levels of PCDD/F and PCB occurrence are consistent with a gradual decline in contamination as reported by some other similar studies. Although all the determined contaminants were detected in the sampled foods, there was poor correlation between the occurrences of the brominated and chlorinated contaminants, and between PBDEs and PBDD/Fs, but better associations were observed between the occurrences of the chlorinated contaminants.

Polybrominated dibenzo-p-dioxins and furans (PBDD/Fs) in Italian food: Occurrence and dietary exposure.

Human exposure to polychlorinated dioxins and furans (PCDD/Fs) through the dietary pathway is widely recognised and regulations in some regions of the world help to limit food contamination. Similar information on the analogous polybrominated dioxins and furans (PBDD/Fs) is scarce, partly due to the higher threshold to analytical access and unavailability of some standard materials. The analytical methodology developed here determined twelve planar PBDD/F congeners using 13Carbon labelled PBDD/F surrogates and high resolution mass spectrometric detection, and was extensively validated prior to the analysis of a range of commonly consumed Italian foods. The methodology also allowed simultaneous determination of PCDD/Fs and polychlorinated biphenyls (PCBs). The results show that PBDD/Fs occurred in different foods over a range of concentrations from <0.001 pg/g to 4.58 pg/g in fish. The dietary exposure (upper bound) of different Italian population groups, resulting from these occurrence levels was estimated using the toxic equivalency (TEQ) approach that is commonly used for dioxin-like contaminants and ranged from 0.17 to 0.42 pg TEQ/kg bodyweight/day (lower bound - 0.01 pg TEQ/kg bodyweight/day) depending on the population subgroup. Although precautionary, upper bound values may provide a more realistic estimate of toxicity as not all congeners and foods were measured. As expected, children were more highly exposed than adults due to lower body weight. These exposure levels were between a quarter and a third of that arising from the sum of PCDD/Fs and PCBs (0.61 to 1.38 pg WHO-TEQ/kg bodyweight/day), but they contribute to dioxin-like toxicity. If this data is considered in view of the revised tolerable dioxin-like dietary intake published by EFSA in 2018, it is evident that the tolerable weekly intake of 2 pg/kg bodyweight/week would be exceeded by some of the assessed population sub-groups, or all sub-groups if the cumulative intake is considered.

Determination of dioxin-like polychlorinated biphenyls in feed and foods of animal origin by gas chromatography and high resolution mass spectrometry.

The authors describe a method to determine 12 dioxin-like polychlorinated biphenyls (dl-PCBs) in feed and foods of animal origin using high resolution gas chromatography and mass spectrometry (HRGC-HRMS). The use of semi-automated apparatus such as an accelerated solvent extraction device and the Power-Prep purification system significantly reduced the sample treatment time necessary before instrumental analysis in comparison with the Soxhlet extraction method or manual purification on columns traditionally used. This method demonstrated good specificity (mild interference limited to PCB 81 and 123 in highly contaminated matrices, such as fish and fish feed), with limits of detection of 0.2-1.3 pg/g of fat. The coefficients of variation for repeatability tests were in the range of 2.6-18.3%, with recoveries of over 80%. The method was successfully applied to the analysis of 177 samples of various foodstuffs specified in the 2005 Italian National Residues Plan: this is the first data on dioxin-like PCB contamination levels in Italy to emerge under this monitoring plan.