Speciation Analysis Of Arsenic In Antarctic Krill And Study On Arsenic Migration During Processing

Antarctic krill(Euphausia superba)is the largest invertebrate small creature in the Antarctic ocean population.Antarctic krill is rich in protein,all amino acids necessary for the human body and various mineral elements such as calcium,magnesium,potassium,sodium,phosphorus,sulfur,and chlorine,as well as phosphorylated protein peptides,phospholipid-based EPA/DHA,and astaxanthin.Functional food ingredients such as esters have high nutritional value.As a treasure trove of new resources for ocean quality protein and active lipids,Antarctic krill has become one of the most important development targets in the world’s ocean fishing industry.The existence of arsenic in the natural world is different,and the toxicity of different arsenic species is very different,so analyzing the existence and content of arsenic becomes very important.At present,there are many studies on the analysis of arsenic species,and more than 30 arsenic species have been found in nature.The forms of arsenic in seawater,algae and seafood include inorganic arsenic and organic arsenic.The most common forms of arsenic are arsenic trioxide(As2O3),arsenite(AsIII),arsenate(AsV)and monomethyl arsenic(MMA),dimethyl arsenic(DMA),arsenic choline(AsC),arsenobetaine(AsB),arsenose,etc.The analysis of arsenic speciation in Antarctic krill is rare.It can be used as a reference for arsenic species in seafood.The toxicity of arsenic is closely related to its chemical form,inorganic arsenic is highly toxic,and organic arsenic is low-toxic or non-toxic.In terms of LD50,the toxicity of arsenic compounds is as follows: AsIII>AsV>MMA>DMA>AsC>AsB.Studies have shown that although the arsenic content in seafood is relatively high,it is mainly in the form of non-toxic organic arsenic.For example,the most important form of arsenic in marine animals such as crabs is arsenobetaine.Therefore,when determining the arsenic content in seafood,it is necessary to analyze the arsenic form,and it is more scientific than simply evaluating the total amount of arsenic.Purpose1.Analyze the arsenic content of total arsenic in the national standard.Determine the total arsenic content of frozen Antarctic krill,Antarctic krill meal,and Antarctic krill oil for the Antarctic krill and its related products.2.Analysis of arsenic species in Antarctic krill and its related products.3.A systematic study of the transfer and variation patterns of total arsenic and arsenic in the processing of Antarctic krill oil.Methods and results1.Comparison of Inductively Coupled Plasma Mass Spectrometry(ICP-MS),Hydride Generation Atomic Fluorescence Spectrometry(HG-AFS)and Silver Salt Method(Spectrophotometry)for the Determination of Total Arsenic in Antarctic Krilland Its Different Forms of Products The applicability of the method and the silver salt method(spectrophotometric method)were used to systematically determine the total arsenic content in frozen Antarctic krill,Antarctic krill meal and different brands of Antarctic krill oil.The results showed that the total arsenic content in Antarctic krill and its products was detected by ICP-MS method,HG-AFS method,and silver salt method(spectrophotometric method).The recoveries of the three methods were100.26~110.48 %,respectively.82.68-98.50 % and 89.64-94.89 %,RSD were less than 5%.The silver salt method(spectrophotometric method)has the advantages of low cost and high applicability in the laboratory.The total arsenic content in frozen Antarctic krill,Antarctic krill meal,and Antarctic krill oil was measured using the silver salt method(spectrophotometric method).For: 0.446 to 0.454 mg/kg,1.040 to1.911 mg/kg,0.522 to 5.502 mg/kg.2.A method for the determination of five arsenic species commonly found in seafood was developed using high performance liquid chromatography-ultraviolet digestion hydride generation atomic fluorescence spectrometry.The lipid methyl esterification method was used to achieve the extraction of arsenic from the Antarctic krill and its products and optimize the conditions for methylation and extraction of arsenic.The extraction rate of arsenic was more than 80%.The column was analyzed by Hamilton PRPx-100 anion exchange chromatography(250 mm×4.1 mm,10 μm).The mobile phase was alternately eluted with two concentrations of ammonium dihydrogen phosphate,arsenobetaine(AsB),arsenite(AsIII),and arsenate.The five arsenic species,salt(AsV),dimethyl arsenate(DMA)and monomethyl arsenate(MMA),were isolated and tested.The analysis of arsenic species in Antarctic krill and its products was achieved through single factor optimization of instrument conditions.The most important form of arsenic in Antarctic krill and its products is arsenobetaine.3.Simulate the production of Antarctic krill oil to obtain dry basis quality.The arsenic species of each node sample during the production of Antarctic krill oil was analyzed by high performance liquid chromatography-ultraviolet digestion hydride generation atomic fluorescence spectrometry.Most of the samples from Antarctic krill oil and its production nodes are non-toxic arsenobetaine and dimethylarsenic,and their proportions are about 90% and 10%,respectively.The total arsenic content of Antarctic krill oil is higher than the national standard,but the morphological analysis is mostly organic arsenic without biological toxicity.In the production process of frozen Antarctic krill to Antarctic krill oil,the proportions of total arsenic in cooking liquor,impurities,filter residue,and shrimp oil were 14.02%,0.02%,18.7%,and 42.0,respectively.Conclusion1.Different detection methods and pre-treatment methods make microwave digestion-ICP-MS and dry ashing-silver salt method(spectrophotometric method)preferable for shrimp oil and shrimp powder with high oil content;for Antarctic krill The whole shrimps were suitable for the three methods.The recoveries of the three methods were between 81% and 108%,and the RSD was less than 5%.Therefore,forcompanies,the silver salt method(spectrophotometric method)is preferred for Antarctic krill-related products for total arsenic detection.2.The most important form of arsenic in Antarctic krill and its related products is that arsenobetaine accounts for about 90% of total arsenic,and DMA accounts for about 10% of total arsenic.3.Arsenic speciation analysis of the Antarctic krill oil production process revealed that the main arsenic species in the frozen Antarctic krill and shrimp oil were AsB and a small amount of DMA,which were about 90% and 10% respectively.The physical processes such as cooking,centrifugation,low-temperature drying,comminution,and ethanol extraction did not convert the arsenic species in Antarctic krill.About 50% of the arsenic in the frozen Antarctic krill migrates to Antarctic krill oil in the form of AsB and a small amount of DMA.