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ObjectiveThe purpose of this investigation was to monitor the contamination characters and spatial and temporal distributions of 23 Per uorinated alkyl substances (PFASs) in seafood along South China Coastal Regions. The exposure risks of PFOA and PFOS to human health in marine aquatic products were also evaluated. MethodsA total of 844 samples including 359 shes, 391 shell shes and 94 crustaceans were collected from Guangdong, Guangxi and Hainan provinces. The samples were extracted and puri ed using a modi ed QuEChERS procedure and analyzed by UPLC-MS / MS. The statistical analysis was performed in view of the detection of different PFAS components in variety of shes, shell shes and crustaceans, respectively. ResultsSixteen PFASs were detected in the survived samples and the total detection rates reached to 99.21 %. The highest ∑PFASs in each sample was 28.27 μg/kg, and the average and medium values of ∑PFAS were 1.83 μg/kg and 1.18 μg/kg, respectively. PFOS and PFBA have been considered as predominant PFAS components with corresponding pollution contribution rates of 29.14% and 24.71%, respectively. However, it is noted that PFNA and PFBS were primarily enriched in the oyster and mussel. During the period of this investigation (2014-2016), ∑PFAS average concentrations turned out constantly rising trend and new pollution component PFHxS detected in 2016. ∑PFAS concentrations of Guangdong, Guangxi and Hainan provinces were approximately at similar level. ConclusionThe contamination status of PFASs were getting worse in South China Coastal Regions. Safety and risk exposure assessments of PFOA and PFOS via daily diet intakes showed relatively low to local residents.

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The edible safety of eugenol-treated fish is one of the concerns limiting the anesthetic applied in the aquaculture industry. The depletion of eugenol was investigated at different water temperatures under the simulated settings of sea bass handling and transport. Sea bass was exposed to eugenol at a concentration of 60 mg/L for 3 min, then immediately transferred to clean water to be purged for 24 h and sampled at different time intervals. The left fish were re-exposed to eugenol in a repeat of the first exposure, purged for 48 h in clean water, and sampled for eugenol detection. Under the simulated settings, the sea bass could accumulate more eugenol residue in fillet when exposed to water at a temperature of 20 °C than that at 13 °C. However, eugenol could be depleted much faster when the sea basses were exposed to the higher water temperature. The half-lives of eugenol in sea bass were 0.28 h and 0.29 h for the first and second purging stage at a water temperature of 20 °C, while at 13 °C, the half-lives were 2 and 4.5 h, respectively. Therefore, increasing the water temperature may be an effective way to accelerate eugenol depletion in fish fillet and reduce exposure risk for the consumer.