Cardiano Paola, Cigala Rosalia Maria, Crea Francesco, Giacobello Fausta, Giuffrè Ottavia, Irto Anna, Lando Gabriele, Sammartano Silvio
Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale F. Stagno d'Alcontres, 31, I-98166 Messina, Vill. S. Agata, Italy.
Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale F. Stagno d'Alcontres, 31, I-98166 Messina, Vill. S. Agata, Italy.
Chemosphere. 2017 Nov;186:535-545. doi: 10.1016/j.chemosphere.2017.08.015. Epub 2017 Aug 7.
The speciation of Al in aqueous solutions containing organic and inorganic ligands important from a biological (citrate (Cit), gluconate (Gluc), lactate (Lac), silicate (HSiO), carbonate (CO), fluoride (F)) and industrial (Gantrez; polymethyl-vinyl-ether-co-maleic acids; GTZ S95 and GTZ AN169) point of view is reported. The stability constants of Al/L complexes (L = ligand with z charge) were determined by potentiometry at T = 298.15 K and 0.10 ≤ I/M ≤ 1.00 in NaCl (in NaNO only for Al/GTZ S95 and Al/Gluc acid systems). For Al/Cit, Al/Lac and Al/GTZ AN169 systems, the investigations were also carried out at 283.15 ≤ T/K ≤ 318.15. The dependence of the thermodynamic parameters on ionic strength and temperature was modelled with a Debye-Hückel type equation. Different speciation schemes of Al/L systems were obtained, including protonated, simple metal-ligand, polynuclear and hydrolytic mixed species. At I → 0 M and T = 298.15 K the stability trend for the AlL species is: 14.28 ± 0.02, 13.99 ± 0.03, 10.16 ± 0.03, 3.16 ± 0.08, 2.84 ± 0.10 for GTZ S95, GTZ AN169, Cit, Gluc and Lac, respectively. From the investigations at different temperatures, it results that the entropic contribution is the driving force of the reactions. The sequestering ability of the ligands towards Al was investigated determining the pL parameter at different experimental conditions, finding the following trend: Cit » Gluc > GTZ S95 > GTZ AN169 > Lac for the organic ligands, and pL: F » CO > HSiO for the inorganic ones.
本文报道了从生物学（柠檬酸盐（Cit）、葡萄糖酸盐（Gluc）、乳酸盐（Lac）、硅酸盐（HSiO）、碳酸盐（CO）、氟化物（F））和工业（甘泰树脂；聚甲基乙烯醚-马来酸共聚物；GTZ S95和GTZ AN169）角度来看重要的含有有机和无机配体的水溶液中铝的形态。通过电位滴定法在T = 298.15 K和0.10≤I/M≤1.00的NaCl溶液中（仅在Al/GTZ S95和Al/葡萄糖酸体系中为NaNO）测定Al/L配合物（L =带z电荷的配体）的稳定常数。对于Al/Cit、Al/Lac和Al/GTZ AN169体系，还在283.15≤T/K≤318.15下进行了研究。用德拜-休克尔型方程对热力学参数与离子强度和温度的依赖性进行了建模。得到了Al/L体系的不同形态方案，包括质子化、简单金属-配体、多核和水解混合物种。在I→0 M和T = 298.15 K时，AlL物种的稳定趋势为：GTZ S95为14.28±0.02，GTZ AN169为13.99±0.03，Cit为10.16±0.03，Gluc为3.16±0.08，Lac为2.84±0.10。从不同温度下的研究结果可知，熵贡献是反应的驱动力。通过在不同实验条件下测定pL参数，研究了配体对铝的螯合能力，发现有机配体的趋势如下：Cit»Gluc>GTZ S95>GTZ AN169>Lac，无机配体的pL：F»CO>HSiO。
