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Vanadium-cerium oxide catalysts, with different V/Ce atomic ratios, were prepared using vanadyl oxalate (VOC 2 O 4 ) impregnated on ceria (CeO 2 ) as precursors. Subsequently, the freshly prepared solids were calcined under a flow of dried air at different temperatures from 400 to 800 °C. These solids have been characterized with different techniques: Raman spectroscopy, thermal analysis (TG-DSC), specific area measurements (BET), EPR, and solidstate 51 V MAS NMR. Different vanadium species in the vanadium-cerium oxide catalysts have been evidenced. Polymeric V-O-V chains, vanadium tetrahedral surface species, and V 2 O 5 phase are stabilized mainly when solids are calcined in the temperature range 400-500 °C. Their formation also depends on the vanadium content. For higher calcinations temperatures (g500°C), CeO 2 reacts with vanadium (V) species to form a CeVO 4 mixed phase. Further to that formation, a single electron is trapped in an oxygen vacancy in the CeVO 4 phase and can be considered as its probe.

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One of the drawbacks of canning is the migration of various chemicals from the package into the food product. This work aimed at analyzing the concentrations of Bisphenol A (in 137 samples) and heavy metals (in 51 samples) of canned tuna commercialized in Lebanon while evaluating the variability across different brands, packing media, layer, and proximity to the expiry date. Accordingly, BPA was detected in 12 samples out of the 137 samples, run in duplicates. The estimated daily intake of BPA for the selected samples (n = 274) was lower than the tolerable daily intake of BPA, 0.004 mg/kg/day. Therefore, there is no health risk associated with BPA as a result of consuming canned tuna commercialized in the Lebanese market. Besides, the study has shown that 66 samples out of 102 were contaminated with Zn whereas 100% of the samples were contaminated with Aluminum and Tin. However, the calculated Health Risk Index of all the considered heavy metals are all within the safe limits as defined by EFSA (European Food Safety Authority) and Codex Alimentarius.