In order to investigate the retention and elimination of furacillin metabolites (semicarbazide,SEM) in the muscle of T.flavidus following the use of furacilin during the breeding process,the aquaculture pond was treated with 0.50 g/m³ of furacillin.Muscle samples of T.flavidus were then collected at regular intervals.The concentrations of SEM were determined using high-performance liquid chromatography-tandem mass spectrometry,and the data was analyzed by using Excel 2013.The results showed that furacillin was rapidly metabolized to SEM in T.flavidus after dosing.The levels of SEM in the muscles increased rapidly,reaching their highest value after approximately 4 days.The elimination rate of SEM was initially fast,but slowed down over time.Even after 77 days following dosing,the residual amount of SEM in the muscles was still around 2.50 μg/kg,which was above the limit of detection.This suggests that SEM has a prolonged residual time in T.flavidus after the administration of furacilin.Based on these findings,it is strongly recommended to strictly prohibit the use of nitrofurans,such as furacilin,during the breeding process of T.flavidus,in order to ensure the quality and safety of puffer fish.

Cadmium pollution in aquatic products was common.In order to investigate the cadmium pollution in aquatic products and assess the health risk,cadmium concentration in aquatic products collected from southern coast of Fujian Province in China were detected form 2017 to 2022,combined with the survey results of dietary consumption of aquatic products to assess the health risk by Monte Carlo method.The results showed that a total of 1 004 aquatic products were detected,while the average concentration of cadmium in various aquatic products decreased in the following sequence:caphalopoda≈crabs>shellfish>algae>shrimp>fish.All kinds of aquatic products except crabs met the standards.About 25.6% crabs exceeded the standards,most of them were sea crabs.The contribution of shellfish,crabs and cephalopods to the cadmium intake of total aquatic products reached 85.8%-93.5%.P50,P90,P97.5 of MOE which reflect the overall resident’s cadmium health risk were far less than the safety limit of 1.According to the assessment by age group,the P97.5 risk value of the juvenile group was 0.687,which was closed to the safety limit.Shellfish and crabs made a great contribution to the variance of the risk value MOE,and their sensitivity reached 86.2%-99.1%.In general,the health risk of cadmium intake in dietary aquatic products of coastal residents in southern Fujian was acceptable,but dietary guidance should be provided for the juvenile group.People cadmium intake in aquatic products was mainly from shellfish,crabs and cephalopods.Eating shellfish and crabs with less cadmium concentration could effectively reduce the cadmium health risk from aquatic products.

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the quantitative determination of mebendazole in aquaculture water.The limit of quantification was 0.5 μg/L.The average recoveries of the three spiked levels ranged from 79.0% to 93.9%.The intra-day and inter-day relative standard deviations (RSDs) were 7.57%-8.27% and 7.43%-8.11%,respectively.The actual application concentrations of 15 μg/L and 50 μg/L were used as the tested concentrations for the elimination experiments of mebendazole in aquaculture water,respectively.The results showed that mebendazole was a photosensitive drug whose photodegradation followed the first-order kinetics.The photolytic degradation rate of mebendazole in outdoor aquaculture water under natural light was more than 80% after 648 h.The elimination half-life of mebendazole was 231.05 h at 15-18℃.At the end of the experiment (648 h),6.4 μg/L of mebendazole was still detected in the high concentration group(50 μg/L).Therefore,the results of this study could provide basic data for the pharmacokinetic study of mebendazole in aquaculture animals.