Analysis And Assessment Of Cadmium And Aluminum In The Ostrea Rivularis

Cadmium is a chemical pollutant,which could do harm to the internal organs and physiological systems of human's body by long-term exposure.Now aluminum is regarded as a low toxic metallic element,will not cause acute poisoning on biology and toxicology,but it will exert toxic effect on human if it is taken in for a long time excessively.With the development of industry and agriculture,cadmium pollution is increasing seriously in shellfish.And different forms of cadmium?aluminum have different toxicities.In view of above reasons,the present study analyzed and evaluated the nutrient components in Ostrea rivularis from south China sea coast,and discussed the effect of visceral mass on the nutrient components.The heavy metals of Cd,Al were analyzed in Ostrea Rivularis and different tissues,which sampled from South China Sea in December,2016,were analyzed by inductive coupled plasma mass spectrometry?ICP-MS?,and investigate the distribution of cadmium,aluminum speciation in Ostrea rivularis,Which was carried out by sequential chemical extraction method and analyzed by inductively coupled plasma mass spectrometry?ICP-MS?,four kinds of chemical reagents were used for the extraction,and the extraction conditions of these solutions were optimized.The results were as follows:?1?The results showed that the contents of water,crude protein,fat and ash in the Ostrea rivularis were 84.90%,7.64%,0.75%and 1.71%,respectively.Sixteen amino acids were found which contained seven essential amino acids in the range of 3.97g/100 g to 7.60 g/100 g,the ratio of EAA/TAA was in range of 33.86%to38.06%.Among of them,methionine acted the first limited amino acid,and flavour amino acids accounted for 38.42%to 43.25%of the total amount of amino acid,there were rich trace elements in Ostrea rivularis,such as Ca,Fe,Zn,and Se.The content of fat in eviscerated Ostrea rivularis was lower than that of the whole,while the protein content was higher than that of the whole Ostrea rivularis.The total amino acid content showed slight increasing to 5.83 g/100 g.Essential amino acid in eviscerated Ostrea rivularis was accounted for 35.59%of total amino acid,while flavour amino acid accounted for 41.16%.The content of mineral elements were similar to the whole Ostrea rivularis,and the content of zinc increased.Therefore,Ostrea rivularis was a kind of aquatic product with good quality and high nutritional value,and the nutritional value was increased slightly in eviscerated Ostrea rivularis.It is of great significance to protect the safety of consumer that remove oyster visceral mass to eat.?2?There were significant differences of heavy mental contents in Ostrea Rivularis from different South China Sea Coast areas?P<0.001?,and the content of heavy mental in the same sea area was also different,and the Al contents were higher than Cd,which average concentrations were 82.55 mg?kg^-1,respectively,while the Cd average contents achieve 1.00 mg?kg^-11 was the lowest.The contents of Cd,and Al in eviscerated Ostrea Rivularis was lower than those of the whole,which average concentration were 52.07,0.77 mg?kg^-1.It was found that the heavy mental Cd and Al contents in different tissues of Ostrea Rivularis were varied,and visceral mass was the main accumulation of heavy metals.The accumulation pattern of Al was according to the order of visceral mass>mantle>gills>gonads,adductor muscle,Cd was visceral mass>gills>mantle>gonads,adductor muscle.?3?The speciation analysis of cadmium in Ostrea rivularis have various chemical forms.Four kinds of chemical reagents were used for the extraction,and the extraction conditions of these solutions were were optimized.The result shows that the optimized extraction parameters were 50 mL 0.5 mol?L^-11 KCl extracting for 5 h,50mL deionized water extracting for 4 h,50 mL 2%acetic acid extracting for 4 h.50 mL1 mol?L^-11 hydrochloric acid extracting for 4 h,Under these conditions,the greatest mount of cadmium was in the extraction of 2%acetic acid,followed by 1 mol?L^-1hydrochloric acid and both forms accounted for 62.72%⁸6.05%,52.04%⁷7.40%of the total cadmium,hydrochloric acid solution can be leached acid-soluble inorganic Cd.The cadmium content in the extraction of deionized water and 0.5 mol?L^-11 KCl were much smaller,which only accounted for 5.21%¹8.31%,7.29%³0.46%of the total cadmium.The content of dissolve cadmium in whole Ostrea rivularis gastric stage is 3.01 mg?kg^-1,which accounted for 55.88%of the total aluminum.There was a significant difference in Cd leaching from simulated gastric juice in different tissues?P<0.05?,with a range of 1.43±0.05⁶.08±0.07 mg?kg^-1.and he dissolution rate ranged from 50.44%to 70.03%.?4?Four kinds of chemical reagents were used for the extraction,and the extraction conditions of these solutions were optimized.The result shows that the optimized extraction parameters were 70 mL 0.5 mol?L^-11 KCl extracting for 2 h,70mL deionized water extracting for 2 h,70 mL 4 mol?L^-11 HCl extracting for 2 h,70 mL HNO₃ extracting for 2 h.Under these conditions,the distribution of aluminum species in the whole Ostrea Rivularis was according to the order of organic Al<Al³⁺<water soluble Al<Al?OH?₃<insoluble Al,insoluble Al accounted for about 77.36%in total aluminum,While the dominating form of toxic inorganic aluminum was Al?OH?₃,which accounted for 15.87%.The percentage of dissolve aluminum in gastric stage accounted for 8.16%³2.11%of the total aluminum,which indicated the aluminum speciation changes in the gastric juice and proved the validity of aluminum after swallowing.