青海平安富Se土壤区环境及人体Se含量调查

通过对平安区三合镇祁新庄、骆驼堡、三合村3个村庄内土壤、饮用水、人体毛发、人体尿液的采样调查分析,并以乐都城台乡坝口村和山城村2个村庄作为Se背景区进行对比研究,认为平安三合富Se土壤产生了明显的生态效应,Se通过土壤-粮食-人体等生物链进行迁移积累,致使人发、人尿中Se水平与土壤Se呈正相关关系,人体Se水平良好响应环境Se状况。     

石墨炉原子吸收法测定水中硒

利用石墨炉原子吸收法,加入基体改进剂测定水中硒,并优化了测定条件。结果表明,本方法检出限低(0 85μg L),准确度高,精密度好。     

TAS-986型石墨炉原子吸收光谱法测定绿茶中的微量硒

利用加入基体改进剂NiNO3，采用TAS-986型石墨炉原子吸收光谱法，对绿茶中的微量硒进行测定分析，结果RSD〈5．0％，回收率在99．0％-100．2％之间。该法简便、快速，测定结果准确可靠。     

痕量硒的示波极谱测定

在０．６０ｍｏｌ／Ｌ醋酸－０．００２０ｍｏｌ／Ｌ对氨基苯磺酸介质中,Ｓｅ（Ⅵ）－对氨基苯磺酸配合物于－０．６３Ｖ处产生一敏锐的单扫描示波极谱波。硒含量在０．３－８０ｎｇ／ｍｌ范围内与波高有线性关系,检出限达０．１５ｎｇ／ｍｌ。利用该波测定实际试样中痕量硒,结果较好。     

The Behaviour of Selenium in Geological Processes

Selenium contents were analyzed from a total of 244 soil samples collected over different rock types at a sampling density of one sample per 4km² around Geita gold mining areas, Northwestern Tanzania. Comparisons using literature survey contents of selenium in geological materials and some implications on the selenium in soils are compiled and discussed. Most selenium occurs as simple selenides in small quantities in low temperature hydrothermal deposits devoid of sulphur. It has been observed that to a large extent selenium content is increased more than most trace elements in the upper parts of the Earth perhaps through extraterrestrial deposition. In deep-seated rocks selenium is associated with sulphur but being volatile selenium and sulphur do not behave according to the crystallochemical law. Due to the higher stability of S⁶⁺, Se⁴⁺ and Se⁰ separate during migration. Thus, selenium is especially found in deep-seated plutonic rocks where large magma bodies cooled slowly and sulphur is available to precipitate sulphides. Selenium, which occurs with sulphides, is inhomogeneously deposited into continental margins. It is increased during magmatic differentiation and is highest in basic rocks. In magmatic and metamorphic conditions, selenium is found in the crystal structures of sulphides while in pneumatolytic and hydrothermal processes, it is relatively enriched into the late differentiates compared to sulphur. In metamorphic rocks selenium is more widely distributed. Selenium content in soils in the investigated area varies from (0.3–0.5gg^–1) in laterite and in black cotton soil 0.4gg^–1. Of all volcanic rocks selenium is highest in volcanogenic rocks especially the basalts. Surface waters are enriched in selenium, which they leach from volcanic materials. Selenium in sediments containing clay and organic matter is elevated but the content decreases with increased metamorphism. Selenium in volcanic areas can be used as a pathfinder in prospecting for volcanogenic ore deposits. S/Se ratios are distinct in different rock types and can thus be used to elucidate the origin of rocks, ores, and sediments.     

TAS-986型石墨炉原子吸收光谱法测定绿茶中微量硒

利用加入基体改进剂NiNO3,采用TAS-986型石墨炉原子吸收光谱法对绿茶中微量硒的分析.RSD＜5.0%,回收率在99.0%～100.2%之间,该法简便、快速,测定结果准确可靠.     

张家口地区土壤硒形态分布及其植物有效性初步研究

分别采集了张家口克山病区非病村4个砂土样品和重病村6个草甸土、褐土样品．用连续提取程序分离出水溶态硒、离子交换态硒、有机态硒、酸溶态硒、硫化物态硒和残余态硒。水溶态硒容易被植物吸收。交换态硒也能被植物吸收，但受到吸附环境和pH值的影响。有机结合态硒只有在碱性条件下其中的富啡酸态硒才能被植物吸收。酸溶态硒是铁锰氧化物和碳酸盐类矿物醚性淋溶作用的结果，酸性条件下硒容易流失，碱性条件下硒被原矿物固定，因此都难被植物吸收利用。硫化物态硒和残余态硒是最难溶的，基本上不被植物吸收。张家口地区重病村土《铁锰氧化物和腐殖质含量高，呈中-微酸性，而非病村正好与之相反。因此，重病村土壤虽然水溶性硒+交换态盾+有机态硒高于非病村，但这三种硒形态所反映的土壤植物有效性反而低于非病村。这可能是病村粮食比非病村低硒的原因。     

中国“硒与健康”数据库应用研究

由“硒与健康”数据库数据研究表明,中国26个省市人发含量量均值与长寿水平间存在着大致线性关系,相关系数达到0.71。135种常用食品含硒量与品种有关,鱼肉禽蛋>油料>豆类>粮食>蔬菜>水果。对克山病、大骨节病病区与非病区环境硒样品数据模式识别处理表明。环境硒水平不足是患病的根本原因之一,而主食大米与否不是本质原因。     

ICP-MS碰撞池技术消除复杂水样中硒的基体干扰

通过测定深圳某河流水样中的主要成分,确定ICP—MS碰撞模式测定se的主要基体干扰,并对碰撞气流量进行条件优化和水样基体干扰消除试验,确定当氦气流量为3．0L／min时,测定77Se的干扰能基本被消除。该方法测定实际水样的结果与原子荧光法的测定值无显著差异。     

土壤中硒的形态

３种江苏省土壤,即潮盐土,灰潮土和黄棕壤原土硒和外加硒的形态分布研究结果表明,原土硒主要分布在残渣态Ｆ５上,３种土壤的Ｆ５的百分含量均达全量硒的８０％左右,而外加硒经４个培养后相对均匀地分布于可溶态Ｆ１（黄棕壤例外）,交换态Ｆ２、氨水提取态Ｆ３和残渣态Ｆ５上,２种处理下硒形态分布与土壤ＰＨ值,粘粒和游离氧化铁含量有一定关系,ＰＨ值是潮盐土≈灰潮土＞黄宗壤,粘粒及游离氧化铁含量是黄棕壤＞潮盐土＞灰质