The effect of gluconate on the solubility and aqueous speciation of An(III) and Ln(III) was studied using a combination of Nd(III) solubility experiments, Cm(III) time-resolved laser fluorescence spectroscopy (TRLFS) and density functional theory (DFT) calculations.

Solubility experiments were performed under an Ar-atmosphere using a well-defined Nd(OH)₃(s) solid phase equilibrated in NaCl (0.1–5.0 M) and CaCl₂ (0.1–3.5 M) solutions with 9 ≤ pH_c ≤ 13 and 10⁻⁶ M ≤ [GLU]_tot ≤ 10⁻² M. The solubility of Nd(OH)₃(s) remains mostly unaffected in NaCl solutions with [GLU]_tot = 10⁻³ M, whereas a clear increase in solubility is observed in dilute CaCl₂ solutions with the same [GLU]_tot and pH_c ≥ 11. In concentrated CaCl₂ solutions, gluconate does not affect the solubility of Nd(III) due to the competition with Ca–GLU complexes.

Cm(III) TRLFS spectra collected in NaCl solutions with pH_c ≈ 12 confirm the formation of weak Cm(III)–GLU complexes. The very strong red shift observed in dilute CaCl₂ solutions in connection with high fluorescence intensities supports the formation of ternary Ca–Cm(III)–GLU complexes. The speciation of Cm(III) in 3.5 M CaCl₂ solutions is mostly dominated by the complex Ca₃[Cm(OH)₆]³⁺, although the formation of ternary Ca–Cm(III)–GLU species is hinted at high gluconate concentrations. DFT calculations provide additional support to the formation of stable ternary Ca–Cm(III)–GLU aqueous complexes.

This work provides key information to understand the chemical speciation and relevant equilibrium processes of An(III) and Ln(III) in the presence of gluconate under conditions relevant for nuclear waste disposal.

结合Nd（III）溶解度实验，Cm（III）时间分辨激光荧光光谱（TRLFS）和密度泛函理论研究了葡萄糖酸对An（III）和Ln（III）的溶解度和水形态的影响（DFT）计算。

溶解度实验使用良好定义的钕（OH）在Ar气氛下进行₃固相在NaCl（0.1-5.0 M）和CaCl平衡（S）₂（0.1-3.5 M）溶液用9≤pH值_Ç  ≤13和10 ^-6 中号≤[GLU]_托特 ≤10 ^-2  M.钕的溶解度（OH）₃（S）在NaCl溶液中保持几乎没有受到影响与[GLU] _TOT  = 10 ^-3 男，而在溶解度的明显增加在稀的CaCl观察_2种溶液用相同的[GLU] _TOT和pH _ç  ≥11.在浓缩的CaCl ₂ 解决方案中，由于与Ca-GLU复合物竞争，葡萄糖酸不会影响Nd（III）的溶解度。

厘米（III）TRLFS光谱在pH NaCl溶液收集_Ç  ≈12确认弱厘米（III）-Glu复合物的形成。在稀CaCl ₂溶液中观察到非常强的红移并伴随着高荧光强度，支持了三元Ca–Cm（III）–GLU复合物的形成。尽管在三价Ca–Cm（III）–GLU物种的形成暗示了高葡萄糖酸盐的存在，但在3.5 M CaCl ₂溶液中Cm（III）的形态主要由复合Ca ₃ [Cm（OH）₆ ] ^3+决定。浓度。DFT计算为稳定的三元Ca–Cm（III）–GLU水性复合物的形成提供了额外的支持。

这项工作提供了关键信息，以了解在与核废料处理相关的条件下，在葡萄糖酸盐存在下，An（III）和Ln（III）的化学形态和相关的平衡过程。