Study On The Species Of Aluminum In Seaweed And Evaluate The Edible Safety Of The Aluminum In Seaweed

Aluminum, widely found in the nature, is a common and abundantmetallic element in the Earth’s lithosphere. Because of its low solubility in neutralcondition, it has been considered to be Non-toxic for a long time. However, as thestudy on environmental acidification becomes intensive in recent, people find that thecontent of dissolved aluminum in the Earth’s surface has an influence on the diebackof forest, the decline of grain harvest and the death of aquatic plants. Therefore, thepotential hazard of Aluminum is aware of by people and its biological functionbecomes the center of in-depth research. A conclusion is drawn that Aluminum, as aLow toxic metallic element, will not cause acute poisoning, but it will exert toxiceffect on human if it is taken in for a long time excessively.The toxicity of aluminum is decided by its existing forms. For Aluminumcompounds, the toxicity of Al3+is stronger than Al(OH)2+and Al(OH)2+, strongerthan AlF3,stronger than Al connect with organic matter.And its toxicity become weakif combined with organic groups. Therefore, the toxicity of inorganic aluminumtoxicity is greater than that of organic aluminum.It is more scientific to analyze theform of distribution than the total determination when exterminating its content andevaluating its toxicity.Edible seaweed is an important product in aquaculture fishing industry in Chinawith its production in our country accounted for about half of world marine Algaeproduction, ranking first in the world. Since the edible seaweed can absorb andaccumulate aluminum compounds, it is found by testing organization that the contentof aluminum in seaweed is very high, making it a source for human intake. Therefore,it is necessary to develop a way to study the forms of aluminum in the edibleseaweed.This article attempts to analyze and determinate aluminum of different forms inseaweed with the help of ICP-MS, single extraction and static continuous extraction.The study investigates the such factors as concentration and volume of extraction. And the different of processing methods,and is ensured by precision and the recoveryof adding of standard. By making a research on laver and other six edible seaweed tofind out the speciation of aluminum and their contents, the results are drawn asfollows:(1) Study on the content of total aluminum: the study applies combine wetdigestion process with inductively coupled plasma-mass spectrometry (ICP-MS)detection to detect the total aluminum of laver and other six seaweeds. It is found thatthe contents of aluminum in the samples collected are of great variety. Take seaweedfor example, the average content is370mg/kg, with a minimum of52mg/kg and amaximum of1652mg/kg. among the sample, about12%has a content of less than100mg/kg,68%has a content between100mg/kg and500mg/kg;14%has a contentbetween500mg/kg and1000mg/kg; and6%has a content of more than1000mg/kg.(2) The speciation of Aluminum in the seaweed: With laver as an example, thestudy extracted different forms of Aluminum by single extraction and staticcontinuous extraction, and then detected them by ICP-MS. It is found that thought thetotal content of aluminum are different among each sample, the content of some formsof aluminum in different sample are within a similar range. The percentage of variousforms of toxicity of Aluminum is less than10%, but the rump-state Aluminum is near80%, showing that most aluminum in the Laver is not toxic.(3) The “bioavailability”of aluminum in Algae after animal/human swallowing:the study used artificial simulation gastric juices which is close to humanphysiological conditions to extract Aluminum in seaweed products, and determinatedthe content of dissoluted aluminum. We found that Aluminum dissolved in simulatedgastric juice is more than that dissolved in water, but less than the acid-solubleAluminum and alkali-soluble Aluminum. The study indicated the Al morphologicalchanges in the gastric juice, and proved the validity of Aluminum after swallowing.(4) Evaluation on the safety of edible Aluminum in Algae: The CAC and theFAO developed a tolerable weekly intake of Aluminum and adult intake aluminumfrom food per week. on the basis of those data, this study takes the forms ofAluminum in seaweed products and the absorption capacity of the human body into account, provides a limited standard for reference.