Study On The Trace Metal Elements Analysis In Entironment And The Eco-Behavior Of Selenium

Lite is associated with environmental elements. The study of the trace analysis and the Eco-Bchavior of these elements play an important role. The mathematical model and kinetic formula of conventional and derivative signal for hydride generation-atomic absorption spectrometry were established for the first time. The method of hydride generation-derivative atomic absorption spectrometry was advanced, which provided improved sensitivity and detection limit and also good reproducibility. The proposed method was applied successfully to the analysis of seven trace elements in the environmental and biological system. The How injection-vapor generation-derivative atomic absorption spectrometry was proposed for the determination of cadmium in foodstuff. The flow injection-online reduction-hydride generation-derivative atomic absorption spectrometry and transformational curve speetrophotometry were proposed to realize the selenium speciation analysis in water and soil extraction samples.The Eco-Behavior of selenium in the biological chain of soil-plant-animal was studied by combining the trace analysis technique with ecology. Selenium in a narrow content range accelerates the growth of the plant (Se4+content<0.5ug ml-1 for radish, and Se4+content<0.5ug ml-1 for onion ). but plants exhibit symptoms of injury when exposed to high concentrations of Se in their root medium. The damage threshold doses of different kind of plants differ greatly. Garlic could tolerate and accumulatemuch higher concentration of selenium than other plants involved in this study. And selenium can reduce the toxicity of cadmium to plants. Different regent was tested to extract different species of selenium from soil, the results show that the NaHCO3-Se is correlative well with the concentration of selenium intake by the plants, so the NaHCO3-Se may be regarded as an index for appraising available selenium in soil. In animal studies, it is concluded that the selenium supplementation could improve the low serum selenium level of rats with liver disease, which may contribute to the prophylactic and clinic medicine research.