| Sea cucumber, squid, mussel, mantis shrimp and other seafood, not only taste is very delicious, and rich nutritional value and popular with residents in coastal regions, many coastal areas have carried out the artificial seedling and breeding. Most of these creatures are filter feeders, especially around under the influence of living environment, the rapid development of industry, oil transportation, offshore drilling platform, the increasingly frequent human activities at sea, and so on many factors, lead to marine heavy metal pollution is more and more serious, as a result, marine creatures are poisoning is inevitable. Life quality increase year by year, more and more people begin to notice the food quality and safety.Heavy metals Cu, Hg, Pb, Cd, As and so on can cause of marine pollution, and, as long as they are absorbed into the organism, they will have a certain stability.If you want to remove them, it will be very difficult. In a short period of time, they may not cause great harm, but these heavy metal accumulation and enrichment of unceasingly, will eventually enter the body through the food chain. Although they do not directly reach the lethal dose, will become the potential killer of human health. Therefore, heavy metal content is more than the national standard of marine products, need a complete set of detection method, based on the Dalian area rich marine resources, three parts of the Dalian coastal the sea creatures (fish, software class, bivalve, crustaceans and cephalopods) of heavy metal pollution are analyzed and testing, to understand the status of the dalian sea area of heavy metal pollution, can also provide reference for seafood food safety information.Based on the sample collection, sample preparation, conditions of microwave digestion and graphite furnace working conditions, such as matrix modifier and sample test in the process of study, established a complete set of detection methods of heavy metal content in seafood. Digestion liquid HNO3-HClO4(4:1) in mixed acid system, digestion liquid product is5ml, digestion time for40min, digestions using temperature programmed mode, is divided into four stages:240w,2min.400w,2min.560w,5min;400w,2min. Using graphite furnace atomic absorption spectrometry (GFAAS) draw each element under test (copper, cadmium, lead) of the standard working curve, the linear regression coefficients can reach more than0.9990. Graphite furnace ashing process has a larger effect on the determination results, especially in the lead, susceptible to interference, in order to improve the ashing temperature and eliminate matrix interference matrix modifier may be added. The experiment tested respectively ammonium dihydrogen phosphate, ascorbic acid as a matrix modifier on the determination results, the effects of ascorbic acid as matrix modifier was finally determined. Copper and cadmium in the ashing loss is very small, do not need to join the improver. Experiments using the standard addition recovery method the reliability of the test method, standard addition recovery was93%～105%, the detection limit are less than0.08μg/g, show that the precision and accuracy of experiment is excellent.The experimental results show that the microwave digestion method has quick response, easy operation, low reagent consumption, etc. And in different parts of the seafood in Dalian area are classified. |
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