Department of Chemistry, Razi University, Kermanshah, Iran.
Anal Methods. 2020 Oct 8;12(38):4682-4690. doi: 10.1039/d0ay01266a.
A new supported liquid membrane (SLM) was designed by using a suitable deep eutectic solvent (DES) as the hydrophobic liquid membrane phase for the selective and facilitated carrier-less transport of Ag+ ions. The deep eutectic solvent was composed of a 4/1 molar ratio of l-menthol/salicylic acid and was impregnated into a microporous polypropylene membrane to prepare a novel carrier-less SLM system. The highly selective facilitated transport of silver ions was accomplished by using sodium thiosulfate as a highly selective stripping agent for Ag+ ions in the aqueous strip phase (SP). Some important factors, including the concentration of picric acid in the feed phase (FP), pH of the two aqueous phases, stirring rate, transport time, and nature and concentration of the stripping agent were also investigated and optimized. In the presence of 2.8 × 10-2 mol L-1 picrate ions as an appropriate ion pairing agent in the FP and 0.025 mol L-1 thiosulfate as a convenient metal ion acceptor in the SP, the amount of Ag+ ion transport found to occur almost quantitatively after 60 min is 90%. Compared with other SLM systems reported in the literature, the designed DES-SLM system exhibited suitable permeability and higher selectivity for Ag+ ion transport from aqueous solutions containing Fe2+, Mn2+, Cu2+, Ni2+, Pb2+, and Cd2+ as competing metal ions.
设计了一种新型支撑液膜（SLM），选用合适的深共晶溶剂（DES）作为疏液膜相，用于Ag+离子的选择性和促进的无载体传输。深共晶溶剂由 4/1 摩尔比的 l-薄荷醇/水杨酸组成，并浸渍到微孔聚丙烯膜中，制备新型无载体 SLM 体系。采用硫代硫酸钠作为高度选择性的 Ag+离子萃取剂，在水相（SP）中进行高度选择性的促进传输，实现了 Ag+离子的高度选择性传输。研究并优化了一些重要因素，包括进料相（FP）中苦味酸的浓度、两相水溶液的 pH 值、搅拌速率、传输时间以及萃取剂的性质和浓度。在 FP 中存在 2.8×10-2mol/L 的苦味酸作为适当的离子对试剂，在 SP 中存在 0.025mol/L 的硫代硫酸盐作为方便的金属离子接受剂的情况下，经过 60min 后，Ag+离子的传输量几乎达到定量，为 90%。与文献中报道的其他 SLM 体系相比，所设计的 DES-SLM 体系在从含有 Fe2+、Mn2+、Cu2+、Ni2+、Pb2+和 Cd2+等竞争金属离子的水溶液中传输 Ag+离子时，表现出适宜的渗透性和更高的选择性。
