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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.

Abstract:The efficient design of stereochemically challenging ring systems by ring opening of heterobicyclic alkenes has become a very important reaction in the chemistry of C À C and C À X bond formation. By using the hitherto applied in situ technique for the generation of the m 2 -bridged, dimeric neutral rhodium complexes, however, the catalytically active species and its concentration remained unidentified. Furthermore, the reaction temperature is at least 80 8C. The application of cationic rhodium(I) solvate complexes (that no longer contain blocking diolefins)shows that a much greater activity and enantioselectivity for the synthesis of 1,2-dihydro-1-naphthols can be reached than was described so far, even at ambient temperature. NMR spectroscopy and X-ray analysis show that a product inhibition during the ring opening reaction takes place that is independent of the nucleophile.

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