Occurrence of polybrominated diphenylethers, hexabromocyclododecanes, bromophenols and tetrabromobisphenols A and S in Irish foods.

The occurrence of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), tetrabromobisphenol A (TBBPA) and other phenolic brominated flame retardants (BFRs) in Irish foodstuffs has been assessed. A total of 53 food samples including eggs, milk, fish, fat and offal were tested. Eighty-one percent of the samples contained at least one measurable PBDE congener. The most abundant and frequently occurring congeners were BDE-47, BDE-49, BDE-99, BDE-100 and BDE-209 with the highest concentrations found in fish, fat and eggs. Summed concentrations for the measured PBDEs ranged from 0.02 µg/kg to 1.37 µg/kg whole weight. At least one HBCD stereoisomer was found in twenty-six percent of the samples with α-HBCD being the most frequently detected. The highest concentrations were found in fat and oily fish samples. TBBPA was only detected in one farmed salmon sample at 0.01 µg/kg. Bromophenol residues were found in fourteen out of the 53 samples, specifically in eggs and fish, with concentrations ranging from 0.28 to 0.98 µg/kg whole weight. These data contribute to the EU-wide EFSA risk assessment on these contaminants that is currently underway.

The determination of monomers and oligomers from polyester-based can coatings into foodstuffs over extended storage periods.

The polymeric coating used in metal packaging such as cans for foods and beverages may contain residual amounts of monomers used in the production of the coating, as well as unreacted linear and cyclic oligomers. Traditionally, although designed for use with plastic food contact materials, food simulants have been used to determine the migration of monomers from coatings into foodstuffs. More recently, food simulants have also been used to determine oligomeric species migrating from can coatings. In the work reported here, the migration of both monomers and oligomers from polyester-based can coatings into food simulants and foodstuffs, some of which were towards the end of their shelf-life, is compared. The concentrations of monomers and selected oligomers in canned foods at the end of their shelf life were found to be significantly lower than those in food simulants, which in turn was lower than those in the extraction solvent acetonitrile.

Identification in residue analysis based on liquid chromatography with tandem mass spectrometry: Experimental evidence to update performance criteria.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is one of the most widely used techniques for identification (and quantification) of residues and contaminants across a number of different chemical domains. Although the same analytical technique is used, the parameters and criteria for identification vary depending on where in the world the analysis is performed and for what purpose (e.g. determination of pesticides, veterinary drugs, forensic toxicology, sports doping). The rationale for these differences is not clear and in most cases the criteria are essentially based on expert opinions rather than underpinned by experimental data. In the current study, the variability of the two key identification parameters, retention time and ion ratio, was assessed and compared against requirements set out in different legal and guidance documents. The study involved the analysis of 120 pesticides, representing various chemical classes, polarities, molecular weights, and detector response factors, in 21 different fruit and vegetable matrices of varying degrees of complexity. The samples were analysed non-fortified, and fortified at 10, 50 and 200 µg kg(-1), in five laboratories using different LC-MS/MS instruments and conditions. In total, over 135,000 extracted-ion chromatograms were manually verified to provide an extensive data set for the assessment. The experimental data do not support relative tolerances for retention time, or different tolerances for ion ratios depending on relative abundance of the two product ions measured. Retention times in today's chromatographic systems are sufficiently stable to justify an absolute tolerance of ±0.1 min. Ion ratios are stable as long as sufficient response is obtained for both product ions. Ion ratio deviations are typically within ±20% (relative), and within ±45% (relative) in case the response of product ions are close to the limit of detection. Ion ratio tolerances up to 50% did not result in false positives and reduced the false negative rate for pesticides with product ions in the low S/N range to <5%. Without ion ratio criterion, two false positives were obtained in 105 non-fortified samples. Although the study has been conducted for pesticides residues in fruits and vegetables, the impact of these findings is believed to extend towards other application areas and possibly support adjustment or consolidation of criteria across other analytical domains.

Investigation into the occurrence in food of veterinary medicines, pharmaceuticals, and chemicals used in personal care products.

Human exposure to emerging contaminants by indirect routes is of increasing interest. This study assessed the contamination of food by chemicals used in human pharmaceuticals (HPs), veterinary medicines (VMs), and personal care products (PCPs). A prioritization study was undertaken to identify the chemicals and food-producing scenarios most likely to result in contamination of food. Around 400 samples of mushrooms, vegetables, aquaculture products, and animal tissues were collected from sites in the United Kingdom, along with aquaculture products imported from Southeast Asia. A number of multianalyte methods were developed and validated for the analysis of the prioritized compounds in these samples. The analysis of all sample-method combinations required approximately 18000 determinations. Around 325 individual residues, including parabens, musk compounds, and antibiotics, were detected in 118 individual samples, but mostly at low nanograms per gram concentrations. Results suggest that the limited contamination of target chemicals occurred in the realistic food-producing scenarios investigated.