The Research Abort Distribution And Characteristics Of Heavy Metals In Polar Multiple Environmental Medium

With the help of the27th Chinese National Antarctica Research Expeditiom and5th Chinese National Arctic Research Expeditiom, sediment samples, sea water samples and biological samples were collected from Prydz Bay, Chukchi sea and Bering Sea. The samples were taken some heavy metals systematically such as chromium, cadmium, arsenic, mercury, nickel and so on. In detail, the thesis including such study as follows:Chapter1The prefaceIn the beginning of this dissertation, the contamination of heavy metals in the oceans and heavy metal speciation are systematically reviewed. The speciation of arsenic and its pretreatment technology are reviewed in detail. Then the detection method of heavy metals and the overview of the study area are introduced in detail. Finally, the research progress of heavy metals in polar region is expounded.Chapter2The determination and distribution characteristics of six heavy metals in the polar region sea waterIn this paper, the chromium, cadmium, arsenic, mercury, nickel, copper and other elements of the sea water were detected by ICP-MS with the collision/reaction cell system. The samples were obtained from Prydz Bay including12stations and Chukchi Sea, Bering Sea including17stations. The results showed that the heavy metal contents in Arctic were generally higher than Antarctica. Compared with the First-Classed Seawater Quality Standard of China, the contents of all of heavy metals in polar region were much lower than it. Then the horizontal distribution of heavy metals of Prydz Bay were analyzed, the study showed there was no obvious consistency among the metals. Based on this, the correlation among the heavy metals was also studied. There was no obvious correlation during different heavy metals in Prydz Bay, while there was good correlation during different heavy metals in Chukchi Sea and Bering Sea.Chapter3The distribution characteristics of heavy metals and rare earth elements in the polar region sedimentsIn this paper, microwave digestion of sediments was carried in MASS Xpress system, digestion system was optimized and then mensurated by ICP-MS. The concentration of target heavy metals was obtained. In the course of the experiments, the method of detecting10kinds of the amount of heavy metals and16kinds of rare earth elements (REEs) was established, and we applied this method to detecting heavy metals and REEs of the sediments. Then the REE distribution patterns were analyzed. The results showed that the patterns were similar between the the Antarctic and Arctic sediments. Both of them showed out that the light rare earth elements (LREEs) were relative enrichment and the heavy rare earth elements (HREEs) were relative loss.Chapter4Simultaneous determination of heavy metals in biological samples of polar region by microwave digestion-inductively coupled plasma mass spectrometryAn inductively coupled plasma mass spectrometric method for the determination of heavy metals in biological samples of polar region was established. The samples were digested by microwave using HNO3-H2O2as oxidants. The results showed the contents of the different samples were significantly different. In terms of arsenic, the content of Casey station reached116.77mg/kg. Compared with seafood limited standards of China, it exceeded thousands of times. It provided a reliable method of aggregate analysis and experimental conditions for heavy metals analysis of other biological samples.Chapter5Determination of arsenic speciation in scomberomorus niphonius by capillary electrophoresis-inductively coupled plasma mass spectrometryA method for the detection of arsenocholine(AsC), arsenobetaine(AsB), As(Ⅲ), dimethylarsinic(DMA), monomethylarsonic(MMA) and As(V) by capillary electrophoresis-inductively coupled plasma mass spectrometry(CE-ICP-MS) was established. The results showed that the six species of arsenic were separated within20minutes under the optimized conditions. Good linearities of6arsenic species were observed in the range from2.0μg/L to50.0μg/L with the linear correlation greater than0.9978, the detection limits were0.10～1.08μg/L and the RSDs(n=5) of the peak areas were smaller than7%. The method was successfully adopted to the determination of the species in scomberomorus niphonius. The recoveries were between93%and98%, and we found the arsenobetaine(AsB) was the main species in the sample. The method was suitable for the analysis of other biological samples with the advantages of good stability, less sample consumption, short analysis time and convenient.