Actinide-based mineral phases occurring in contaminated soils can be solubilized by organic chelators excreted by plants, such as citrate. Herein, the efficiency of citrate towards U and Pu extraction is compared to that of siderophores, whose primary function is the acquisition of iron(III) as an essential nutrient and growth factor for many soil microorganisms. To that end, we selected desferrioxamine B (DFB) as an emblematic bacterial trishydroxamic siderophore and a synthetic analog, abbreviated (L^Cy,Pr)H₂, of the tetradentate rhodotorulic acid (RA) produced by yeasts. Firstly, the uranyl speciation with both ligands was assessed in the pH range 2–11 by potentiometry and visible absorption spectrophotometry. Equilibrium constants and absorption spectra for three [UO₂(DFB)H_h]^(h−1)+ (h = 1–3) and five [UO₂(L^Cy,Pr)_lH_h]^(2+h−2l)+ (−1 ≤ h ≤ 1 for l = 1 and h = 0–1 for l = 2) solution complexes were determined at 25.0 °C and I = 0.1 M KNO₃. Similar studies for the Fe³⁺/(L^Cy,Pr)^2– system revealed the formation of five species having [Fe(L^Cy,Pr)]⁺, [Fe(L^Cy,Pr)OH], [Fe(L^Cy,Pr)(OH)₂]^–, [Fe(L^Cy,Pr)₂H], and [Fe₂(L^Cy,Pr)₃] compositions. Then, the ability of DFB, (L^Cy,Pr)H₂, and citrate to solubilize either U or Pu from pitchblende-rich soils (soils 1 and 2) or freshly plutonium-contaminated soils (LBS and PG) was evaluated by performing batch extraction tests. U was extracted significantly only by citrate after a day. After one week, the amount of U complexed by citrate only slightly exceeded that measured for the siderochelates, following the order citrate > (L^Cy,Pr)H₂ ≥ DFB ≈ H₂O, and were comparatively very low. Pu was also more efficiently extracted by citrate than by DFB after a day, but only by a factor of ~2–3 for the PG soil, while the Pu concentration in the supernatant after one week was approximately the same for both natural chelators. It remained nearly constant for DFB between the 1st and 7th day, but drastically decreased in the case of citrate, suggesting chemical decomposition in the latter case. For the Fe-rich soils 1 and 2, the efficiencies of the three chelators to solubilize Fe after a day were of the same order of magnitude, decreasing in the order DFB > citrate > (L^Cy,Pr)H₂. However, after a week DFB had extracted ~1.5 times more Fe, whereas the amount extracted by the other chelators stayed constant. For the less Fe-rich LBS and PG soils contaminated by Pu, the amounts of extracted Fe were higher, especially after 7 days, and the DFB outperformed citrate by a factor of nearly 3. The higher capacity of the hexadentate DFB to extract Pu in the presence of Fe and its lower ability to mobilize U qualitatively agree with the respective complexation constant ratios, keeping in mind that both Pu-containing soils had a lower iron loading. Noticeably, (L^Cy,Pr)H₂ has roughly the same capacity as DFB to solubilize U, but it mobilizes less Fe than the hexadentate siderophore. Similarly, citrate has the highest capacity to extract Pu, but the lowest to extract Fe. Therefore, compared to DFB, (L^Cy,Pr)H₂ shows a better U/Fe extraction selectivity and citrate shows a better Pu/Fe selectivity.

污染土壤中发生的基于系元素的矿物相可以通过植物排泄的有机螯合剂（例如柠檬酸盐）溶解。在此，将柠檬酸盐对U和Pu的提取效率与铁载体的效率进行了比较，铁载体的主要功能是获得铁（III）作为许多土壤微生物的必需养分和生长因子。为此，我们选择了去铁草胺B（DFB）作为象征性细菌三异羟肟酸铁载体和酵母产生的四齿杜鹃花酸（RA）的合成类似物，缩写为（L ^Cy，Pr）H ₂。首先，通过电位法和可见光吸收分光光度法在2-11的pH范围内评估了两个配体的铀酰形态。三种[UO _2]的平衡常数和吸收光谱（DFB）H _ħ ] ^{（ħ -1）+}（ħ  = 1-3）和五个[UO ₂（L ^CY，镨）_升ħ _ħ ] ^{（2+ ħ -2升）+}（-1≤  ħ  ≤1对于l  = 1和h  = 0–1（对于l  = 2））在25.0°C和I  = 0.1 M KNO _3的条件下确定了溶液络合物。对Fe ³⁺ /（L ^Cy，Pr）^2–系统的类似研究表明，形成了五个具有[Fe（L ^Cy，Pr）] ^+的物种。，[Fe（L ^Cy，Pr）OH]，[Fe（L ^Cy，Pr）（OH）₂ ] ^–，[Fe（L ^Cy，Pr）₂ H]和[Fe ₂（L ^Cy，Pr）₃ ]组成。然后，通过执行以下操作，评估了DFB，（L ^Cy，Pr）H ₂和柠檬酸盐从富含沥青的土壤（土壤1和2）或刚被lu污染的土壤（LBS和PG）中溶解U或Pu的能力。批量提取测试。一天后仅通过柠檬酸盐显着提取U。一周后，按照柠檬酸盐>（L ^Cy，Pr）H的顺序，与柠檬酸盐络合的U量仅略高于铁螯合物的U量。₂  ≥DFB≈ħ ₂ O，并且是相对非常低。一天后，柠檬酸盐比DFB提取Pu的效率更高，但PG土壤的Pu含量仅为2-3倍，而两种天然螯合剂在一周后上清液中的Pu浓度大致相同。在第1天至第7天之间，DFB几乎保持恒定，但在柠檬酸盐的情况下急剧下降，这表明在后者的情况下会发生化学分解。对于富铁的土壤1和2，三种螯合剂一天后增溶铁的效率处于相同的数量级，以DFB>柠檬酸盐>（L ^Cy，Pr）H ₂的顺序降低。。但是，一周后，DFB提取的铁量增加了约1.5倍，而其他螯合剂提取的量保持不变。对于富铁含量较低的LBS和PG土壤，Pu污染程度较高，尤其是7天后，Fe的提取量较高，而DFB的表现优于柠檬酸盐约3倍。 Fe的存在及其较低的动员U的能力在质量上与各自的络合常数比率相符，请记住，两种含Pu的土壤中铁的含量均较低。明显地，（L ^Cy，Pr）H ₂与DFB溶解U的能力大致相同，但与六齿铁载体相比，其Fe的迁移量要少。类似地，柠檬酸盐具有最高的提取Pu的能力，但最低的提取Fe的能力。因此，与DFB相比，（L ^Cy，Pr）H ₂显示出更好的U / Fe萃取选择性，柠檬酸盐显示出更好的Pu / Fe选择性。