摘要
通过凝胶层析法对土壤腐植酸进行了分组提取，并对其各分子量分级组成及其与Ｃｄ、Ｚｎ的络合特性进行了研究。结果表明：土壤胡敏酸通过Ｇ５０可以分成３个较集中的组分，分子量分别为Ｍ＝７８１８０、Ｍ＝４８３３９及Ｍ＝２２８６３；通过Ｇ１００可以得到２个组分，分子量分别为Ｍ＝６３３４３和Ｍ＝１９８７０。富里酸通过Ｇ５０、Ｇ１００层析，则从总体上成为单一的宽带，分子量约为Ｍ＝２３００。腐植酸对Ｃｄ、Ｚｎ络合量的测定显示：胡敏酸对Ｃｄ、Ｚｎ的络合量呈２个明显的峰值，而富里酸只有１个峰值。两者对Ｃｄ、Ｚｎ络合量随洗脱体积的变化曲线与其吸光值随洗脱体积的变化曲线相一致。６５Ｚｎ示踪技术研究６５Ｚｎ与胡敏酸、富里酸络合的结论与常规方法一致。
The measurement for molecular weight of humic acids gradations in the drab soil showed that the humic acid could be separated into three gradations of molecular weight using gel filtration by G\|50 and two gradations by G\|100,the molecular weights by G\|50 were 78180,48339,22863 and molecular weights by G\|100 were 63343 and 19870 respectively.While fulvic acid had only one gradation by both G\|50 and G\|100,the molecular weight was 2300 approximately.The measurement for complexaton capacity of cadmium(zinc)\|humic acids showed that the contents of Cd(Zn)\|humic acid had two peak values with the volume of eluent compounded by cadmium(or zinc).The Cd(or Zn)\|fulvic acid had only one peak value.The curve between contents of Cd(Zn)\|humic acid and the volume of eluent met with the curve between spectrum and the volume of eluent.The experiment conducted by radioisotope tracer technique indicated that the complexation capacity of 65Zn\|humic acids changed with different gradations of humic acids,the complexation curve met with the spectrum curve on the whole,i.e.the value of 65Zn\|humic acid had two peak values, while the 65Zn\|fulvic acid had only one,indicating that the use of radioisotope tracer technique could eliminate the intervention accompanied by other heavy metal ions.
出处
《核农学报》
CAS
CSCD
1999年第4期236-241,共6页
Journal of Nuclear Agricultural Sciences
基金
国家自然科学基金
国家核工业基金
关键词
凝胶层析
腐植酸
分子量
重金属
土壤
Gel filtration
humic acids
molecular weight
heavy metal
complexation capacity
