Pesavento M, Soldi T, Profumo A
Dipartimento di Chimica Generale, Università di Pavia, V. Taramelli 12, 27100 Pavia, Italy.
Talanta. 1992 Aug;39(8):943-51. doi: 10.1016/0039-9140(92)80276-j.
Gallium(III) is sorbed by a strong base anion exchange resin loaded with a sulphonated azo-dye, T-azo-R [1-(tetrazolylazo)-2-hydroxynaphthalene-3,6-disulphonic acid], which is able to complex it in aqueous solution. As sorption takes place at acidities at which the hydrolysis of gallium is not negligible, it must be considered as conconmitant equilibrium. The distribution equilibria depend on the amount of ligand sorbed, and on the volume, acidity and ionic composition of the aqueous solution, according to the Gibbs-Donnan model. The thermodynamic complexation constant in the resin phase can be calculated from the experimental distribution coefficients; the value of log K = -1.24(0.20) is in acceptable agreement with that in aqueous solution [log K = -0.75(0.33)] which was also determined in the present investigation. Two equations deriving from the Gibbs-Donnan model are used for predicting the conditions for sorption and elution of gallium by a batch procedure, and for separating it from aluminium.
镓(III) 被负载有磺化偶氮染料T-azo-R [1-(四唑基偶氮)-2-羟基萘-3,6-二磺酸] 的强碱性阴离子交换树脂吸附，该染料能够在水溶液中与镓络合。由于吸附在镓水解不可忽略的酸度下发生，所以必须将其视为伴随平衡。根据吉布斯-唐南模型，分配平衡取决于吸附的配体数量以及水溶液的体积、酸度和离子组成。树脂相中的热力学络合常数可由实验分配系数计算得出；log K = -1.24(0.20) 的值与在水溶液中测定的值 [log K = -0.75(0.33)] 具有可接受的一致性，该水溶液中的值也是在本研究中测定的。由吉布斯-唐南模型推导得出的两个方程用于预测通过分批程序吸附和洗脱镓以及将其与铝分离的条件。
