Zhang Y J, Bryan N D, Livens F R, Jones M N
Department of Chemistry, University of Manchester Manchester M13 9PL, UK.
Environ Pollut. 1997;96(3):361-7. doi: 10.1016/s0269-7491(97)00041-9.
The interactions of a range of actinide elements (Th, U, Np, Pu, Am) with humic substances from the Needle's Eye natural analogue site were studied by gel permeation chromatography. Bulk humic substances were isolated by ammonia extraction, followed by dialysis against distilled water and freeze-drying. The gel permeation results suggest that Needle's Eye humic substances can be fractionated into three incompletely resolved fractions with average molecular weights determined by analytical ultracentrifugation around 49 000 for Fraction 1, around 14 700 for Fraction 2 and around 8000 for Fraction 3. Although there are significant differences between the organic matter elution patterns in individual gel permeation experiments, presumably due to differences in column packing, these are much smaller than the differences between metal ions. The uranium that is naturally present in these humic substances is largely bound in the late-eluting fraction. Spikes of the early actinides, including Np and Pu in controlled valency states, have been added to the humic substances, and gel permeation of the spiked humic substances shows that the three humic fractions vary greatly in their effectiveness and selectivity as ligands for early actinides.
通过凝胶渗透色谱法研究了一系列锕系元素（钍、铀、镎、钚、镅）与针眼天然模拟场地腐殖质的相互作用。通过氨萃取分离出大量腐殖质，然后用蒸馏水透析并冻干。凝胶渗透结果表明，针眼腐殖质可分为三个未完全分离的组分，通过分析超速离心法测定的平均分子量，第1组分为约49000，第2组分为约14700，第3组分为约8000。尽管在单个凝胶渗透实验中有机物洗脱模式存在显著差异，推测是由于柱填充的差异，但这些差异远小于金属离子之间的差异。这些腐殖质中天然存在的铀主要结合在洗脱较晚的组分中。已将包括处于可控价态的镎和钚在内的早期锕系元素加入到腐殖质中，对加标腐殖质进行凝胶渗透分析表明，这三种腐殖质组分作为早期锕系元素配体的有效性和选择性差异很大。
