[Study on selenium and polysaccharide distribution in different time ginkgo leaf].

Selenium and selenium speciation in gingko leaf is different in different vegetal period. Each kind of dissolved selenium varies with the seasons. The total selenium content in gingko leaf picked in different season was studied and the various dissolved selenium content distribution was discussed.

[Determination of micro amount of tellurium (IV) in crude selenium sample by kinetic-specatrophotometry].

A new indicator reaction based on the interaction of sodium sulfide reducing properties with methylene blue in cetyltrimethylammonium bromide pH 3.8 acetic acid buffer solution was put forward to determine micro amount of tellurium. The effect of concentration of reaction substances, acidity, interfering ions etc.

[Determination of active species of heavy metals in sewage sludge by ICP-MS].

Sewage sludge samples for the research from the sewage disposal plants of the north, Mantang River and Xiannu River in Shenyang were extracted and separated by H2O, HAc and organic solvents of different polarities. The active species of Cd, Pb, Cu, Zn and Cr existing in the sewage sludge were determined by ICP-MS, and the regularity and influential factors were studied under the alternation of environmental conditions. The results showed that the content of acid-soluble heavy metals was more than that of water-soluble ones, and both had coincident regularity under the alternation of time and temperature; the content of the organic solvents was positively correlated to the solvent polarity.

[Separation and determination of selenium polysaccharide in enriched-Se cordyceps militaris].

In the present paper, the water soluble selenium polysaccharide was extracted, and isolated and purified preliminarily. The traditional method was used to extract selenium polysaccharide, which was extracted by water and sank by ethanol. The work also focused on the determination of the experiment conditions, optimizing the experiment conditions such as proportion of extract solution, extract temperature, extract times, proportion of ethanol, and standing time.