Adsorptive stripping voltammetry of some trace elements in biological samples,II: Nickel,arsenic, aluminium and selenium

A study of the adsorptive stripping voltammetry of nickel, aluminium, selenium and arsenic is reported in which 2,5-dimercapto-1,3,4-thiadiazole (DMTD) has been used as a chelating agent. By a suitable choice of deposition potential, deposition time, reagent reaction time and other operating conditions, the determination of the four elements could be achieved.By the use of benzyltrimethyl ammonium methoxide as a digesting solvent, it was possible to apply the procedure to the direct determination of the four elements in biological samples.     

地质环境中微量元素与人类心血管疾病

介绍了地质环境中三种微量元素硒，铜，钼的分布特点及与人类心血管疾病的关系。     

Transformations of 1,2,3-Selenadiazoles. (Review)

Published data of the last 15 years and the results of the authors' own investigations on the chemical properties of selenadiazoles are reviewed.     

Studies of the naturally occurring biomethylation of selenium and the determination of the products

A systematic study of the biomethylation of selenium and the determination of the methylated species indicates preliminarily that selenium is susceptible to natural biomethylation under certain environmental conditions. Detectable levels of methylated selenium species, including dimethyl selenide [(CH₃)₂Se], dimethyl diselenide [(CH₃)₂Se₂] and dimethylselenone [(CH₃)₂SeO₂] have been detected by gas chromatography – graphite furnace atomic absorption spectrophotometry (GC – GF AA) from a variety of environmental samples. Findings of naturally methylated selenium species from both soil samples and related air samples suggest that there may exist a localized cycle of selenium between ground soil and the ambient air. Factors that influence the sensitivity and accuracy for the determination of alkyl selenide compounds by GC – GF AA have also been investigated. Flashlike injection mode and addition of about 10% of hydrogen gas to the argon carrier gas provide for highly sensitive detection. Reproducible determination can be obtained with a precision of about 6% and the detection limits are 0.3 ng Se m^?3.     

煤中Se、Cd在焦化过程中迁移规律的研究

利用现代分析测定仪器和实验室模拟手段,以煤及固相(焦炭)、液相焦化产物(焦油、氨水)、气相焦化产物(煤气)中有害微量元素镉(Cd)、硒(Se)为研究对象。通过测定,比较不同煤化度煤种微量元素的含量,并归纳探讨了配合煤中Cd、Se元素在焦化过程中的迁移规律。发现煤化度不同的煤中,镉元素随着煤变质程度升高而减少;硒元素含量对比:QFFM,JM和SM中含量相差不大。在模拟焦化温度1 000℃环境下,分别有45%的硒和48%的镉元素转移到焦炭中,2%的硒和7%的镉转移到氨水中,12%的硒和15%的镉转移到焦油中,并通过物料衡算,发现有41%的硒和30%的镉释放到煤气中。     

Atmospheric pressure chemical vapour deposition of selenium and tellurium films by UV laser photolysis of diethyl selenium and diethyl tellurium

Excimer laser‐induced photolysis of gaseous diethyl selenium and diethyl tellurium (C₂H₅)₂M (M = Se, Te) is controlled by cleavage of both M? C bonds, it yields C₁–C₄ hydrocarbons (ethene as major product) and results in chemical vapour deposition of selenium films and nanosized tellurium powder. The selenium and tellurium properties were characterized by X‐ray photoelectron spectroscopy and Scanning electron Microscopy techniques. Copyright © 2001 John Wiley & Sons, Ltd.