Forms and Behavior of Selenium in Soil-Plant System.

1. 建立了高效液相色谱-荧光检测法测定环境样品中硒的方法。用该方法测定土壤中硒的总含量和可溶性含量，重现性和灵敏度高。此外，该方法可用于土壤萃取物中硒的分级测定。以日本京都龟冈地区50块栽培土壤为研究对象，测定了土壤中总硒和可溶性硒的含量。耕层土壤平均全硒含量为0.288 ppm。水溶硒含量为8.9 ppb，热水溶硒含量为20.4 ppb，分别占总硒含量的3.1%和7.2%。总硒含量与可溶性硒含量相关性显著。通过Sephadex G-25凝胶层析，发现土壤中大部分可溶性硒以有机形式存在。有机硒占耕地土壤硒提取量的69%。此外，认为有机硒主要以氨基酸的形式存在于蛋白质、肽中。通过向土壤中添加三甲基硒离子（TMSe），研究了动物尿硒代谢产物三甲基硒离子（TMSe）的行为。发现添加的TMSe迅速分解为气态Se化合物。由此认为，TMSe在土壤中几乎不可能以有机硒的形式存在。由于土壤硒易溶于碱性溶液，因此对碱溶性硒的形态进行了研究。无机硒一直被认为是土壤硒的主要形式，但研究结果表明，土壤硒以有机形式存在的比例更大。

1. A method for the determination of selenium (Se) in environmental samples was developed by use of high-performance liquid chromatography with fluorescence detection. By this method, the total and soluble amounts of Se in soils could be determined with a high reproducibility and sensibility. Moreover, the proposed method could be applied to the fractional determination of Se in soil extracts.2. About 50 cultivated soils (Kameoka, Kyoto) were used for the determination of total and soluble Se in the soils. The average total Se content of plow layer soil was 0.288 ppm. Water-soluble and hot-water soluble Se were 8.9 and 20.4 ppb, which amounts to 3.1% and 7.2% of total Se. The correlations between total and these soluble Se were significantly high.3. A large proportion of the soluble Se in soils was found to be in an organic form by means of Sephadex G-25 gel-chromatography. The organic Se amounted to 69% of the Se extracted from the cultivated soils. In addition, it was considered that the organic Se was mainly contained as a form of amino acid in proteins, peptides.4. A behavior of trimethylselenonium ion (TMSe) which is an important urinary Se metabolite of animals was studied by adding TMSe to a soil. The added TMSe was found to be decomposed rapidly into gaseous Se compounds. From this result, it was considered that TMSe would hardly occur as organic Se in soils.5. Because soil Se easily dissolves in an alkaline solution, the form of alkali soluble Se was studied. Inorganic species have been considered to be the dominant forms of soil Se, but the result of the study has shown that greater part of soil Se occurs in organic forms.