| Antarctic krill(Euphausia superba)is a potential huge fishery resource in the 21 st century,has attracted the attention of all countries in the world.However,high arsenic has been one of important factors that limited its commercial development.This study developed method for the determination of six arsenic species in Antarctic krill and its products,and analyzed the content and distribution of total arsenic and arsenic species in Antarctic krill and its products.By changing the storage conditions,destructive conditions and digestion of gastrointestinal fluid conditions were used to evaluate the stability of arsenic species in Antarctic krill and its products.Animal experiments were used to study the metabolism,transformation and accumulation of arsenic in Antarctic krill oil in mice.In order to effectively control the transformation of arsenic species in Antarctic krill and its products,to deeply investigate the metabolism and accumulation of arsenic species in organisms,with a view to providing basic research for the commercial development of Antarctic krill,the main research results were as follows:(1)A high performance liquid chromatography-(ultraviolet)hydride generation-atomic fluorescence spectrometry(HPLC-(UV)HG-AFS)method was development for the determination of six arsenic species in Antarctic krill and its productsVarious instrumental conditions such as concentration and p H of mobile phase,pump speed,negative high pressure and pretreatment conditions were optimized.Under the optimal conditions,there were good linear relationship for arsenite(As(?))?arsenate(As(?))?methylarsonate(MMA)?dimethylarsinate(DMA)?arsenic betaine(As B)and arsenic choline(As C)in the range of 5 ? 100 ?g/L with correlation coefficients(r2)larger than 0.9990.The limits of detection(LOD,S/N ? 3)and quantification(LOQ,S/N?10)were 0.01 mg/kg and 0.03 mg/kg,respectively.Average recoveries at three spiked levels of 0.01?0.05?0.10 mg/kg were in the range of 89.2%?108.5% with relative standard deviations(RSD,n=6)of 3.4%?13.9%.The developed method is simple,wide-ranging,accurate and reliable,and could be applied in the speciation analysis of arsenic in Antarctic krill and its products.(2)Analysis of arsenic species and content distribution in Antarctic krill and its productsUsing hydride generation atomic fluorescence spectroscopy(HG-AFS)and the above method to analyze the total arsenic and six arsenic species of Antarctic krill and its products and 13 kinds of aquatic products,respectively,it can be known that the total arsenic contents were 0.2999?4.1518 mg/kg.The total arsenic content of Antarctic krill powder is the highest,and there is no significant difference in total arsenic content among different tissues(P>0.05).The contents of inorganic arsenic speciations(As(?)and As(?))of Antarctic krill and its products and 13 kinds of aquatic products were lower than the national limit standard for aquatic products and their products(0.5 mg/kg).The main arsenic specie was As B in Antarctic krill and its products,which accounting for 51.94%?99.84% of the total arsenic content.(3)The stability of arsenic in Antarctic krill was studiedAfter adjusting the storage conditions of Antarctic krill,the destructive conditions and the digestive conditions of artificial gastrointestinal fluid of Antarctic krill oil,HPLC-(UV)HG-AFS was used to determine the main arsenic specie content in the Antarctic krill sample.It provided a reference for the study and application of arsenic species stability in Antarctic krill.After the Antarctic krill was stored under freezing(-18?)? refrigerated(4?)? normal temperature(25?)? high temperature(60?)and light conditions,Antarctic krill oil under destructive conditions such as accelerated oxidation,microwave and ultrasonic with gastrointestinal digestive enzymes and digestion time effected on As B content in Antarctic krill and its products,respectively.The results showed that there was no significant change(P>0.05)in As B content of Antarctic krill under freezing,refrigerated,high temperature and light conditions.At normal temperature,As B content and quality of decreased significantly(P<0.05)due to the effects of enzymes and microorganisms in the krill.Sensory quality and p H in the krill were reduced under normal temperature,high temperature and light conditions.Antarctic krill oil has reduced As(?)content after accelerated oxidation,microwave and ultrasound,appeared(0.8020±0.2764)mg/kg of DMA in krill oil after accelerated oxidation.During in vitro simulated gastrointestinal fluid digestion,digestive enzymes and digestion time had a significant effect on As B content in Antarctic krill oil(P<0.05),through gastrointestinal digestion continuously As(?)was converted to DMA in Antarctic krill oil with As B content increaseed.During storage and in vitro digestion of Antarctic krill,inorganic arsenic content was reduced and toxicity was reduced.(4)The metabolism of arsenic in Antarctic krill oil in mice was studiedUsing animal experiments,Antarctic krill oil was administered to ICR mice at low?medium and high doses of 1?5?10 g/kg·BW,respectively,and physiological saline was administered as blank group.Through short-term experiment and long-term experiment,the metabolic transformation and accumulation of arsenic in Antarctic krill oil were analyzed.The total arsenic content of excreta(excretion A and excretion B)in mice after taking Antarctic krill oil for 24 hours accounted for 90.25%?94.80% of the total arsenic content,that is,the absorption rate of arsenic in Antarctic krill oil in mice was 6.20%?9.75%.The arsenic species in the excretion were As(?)?DMA?As B and As C.The As B content was the highest and has a negative correlation with the gavage dose.The As C was converted from other arsenic compounds in mice and its content increased significantly with the dose of gavage(P<0.01).The intake of As(?)was converted to As(?)or DMA,and the content of As(?)and DMA changed significantly,but there were no correlation with the gavage dose.After ingesting Antarctic krill oil for 60 days continuously,the mice in each group grew well without poisoning.The body weight of the mice in the middle and high dose groups was significantly lower than that in the blank group(P<0.05).After 20?40 and 60 days of gavage,the organ indexes of liver and kidney were not significantly different from those of the blank group(P>0.05).Six arsenic compounds were not detected in the liver and kidney of each group of mice.With high levels of arsenic in Antarctic krill oil for 60 days will not affect the content and distribution of arsenic species in the liver and kidney of mice. |
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