Research on accumulation and elimination of semicarbazide in Chlamys farreri

Accumulation and elimination of semicarbazide(SEM)in adductor,mantle and gill,digestive diverticula of Chlamys farreri were studied using ultra performance liquid chromatogram tandem mass spectrometry under laboratory conditions in this work.The Chlamys farreri was divided randomly,then exposed to seawater containing 1.0 μg/L,5.0 μg/L and 20.0 μg/L SEM for 8 d at(14±2)℃.With the increase of SEM concentration in seawater,the accumulation amount in three various tissues was increased.The digestive diverticula has the maximum of the biggest concentration(Cmax),average elimination speed and the greatest accumulation ability of SEM.The accumulation capability was as follows:digestive diverticulamantle and gilladductor;and the accumulation amount increased with the addition of SEM concentration in seawater,presenting significantly positive correlation.SEM was accumulated mainly in digestive diverticula and mantle and gill,and the content of SEM in adductor was relatively lower.The elimination capability was as follows:adductormantle and gilldigestive diverticula;but the SEM content in adductor could be reduced to less than 0.50 μg/kg after a period of purification at higher concentration.DAS 2.0 pharmacokinetic parameter calculation program was used to process SEM content-time data and to calculate the relevant pharmacokinetic parameters.The results indicated that area under concentration-time curve(AUC)differed greatly in the three tissues and the tissues had different accumulation capability.For example,in the concentration of 20.0 μg/L,the content of SEM in adductor,mantle and gill,digestive diverticula was 5.94 μg/kg,9.87 μg/kg and 15.81 μg/kg respectively after 42 d elimination experiment,which were also much higher than the specified values.When C.farreri was bred in clean seawater,the SEM accumulated in the body was eliminated significantly.The excretion rate in adductor,mantle and gill,digestive diverticula was 91.3%,90.0%,89.6% and gradually reduced.Under the experimental conditions,when C.farreri was exposed to seawater containing 1.0 μg/L,5.0 μg/L and 20.0 μg/L SEM for 8 d at(14±2)℃,it was recommended withdrawal period of 15 d,50 d and 70 d respectively.When the water temperature was highter than the experimental conditions,the withdrawal period could be shortened;or extended in lower water temperature.The accumulation and elimination curves of SEM in C.farreri provided useful information for studying decontamination of seashells that have SEM contamination.