Schroeder S G, Chow A
Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.
Talanta. 1992 Jul;39(7):837-47. doi: 10.1016/0039-9140(92)80104-l.
The sorptive capacity of the polyether-based foam was determined to be between 0.85 and 0.92 moles/kg for the platinum-tin(II) chloride complex. At hydrochloric and hydrobromic acid concentrations up to 3.0M, the platinum-tin(II) bromide complex had higher extraction efficiencies than the platinum-tin(II) chloride complex. Sorptions were optimized at 5.0M hydrochloric acid and 3.0M hydrobromic acid and distribution ratios as high as 2.0 x 10(5) 1./kg were observed at high foam:platinum ratios. The percent of platinum extracted increased when the alkali metal cations are added in the order K(+) < Na(+) < Li(+) for polyether foam, and decreased in the order K(+) > Na(+) > Li(+) for polyester foam. Also, the sorption efficiencies increased as the proportion of poly(ethylene oxide) of the foam was increased. A Scatchard plot analysis shows that there is a 2:1 ratio of loosely bound platinum to tightly bound platinum with the polyether foam, however, the experimental results are consistent with a weak-base anion exchange mechanism as the prominent method of sorption. For polyester foam, results are consistent with a solvent-like ion-pair sorption mechanism.
聚醚基泡沫对氯化铂 - 锡（II）配合物的吸附容量测定为0.85至0.92摩尔/千克。在盐酸和氢溴酸浓度高达3.0M时，溴化铂 - 锡（II）配合物比氯化铂 - 锡（II）配合物具有更高的萃取效率。在5.0M盐酸和3.0M氢溴酸条件下吸附达到最佳，在高泡沫与铂比例下观察到分配比高达2.0×10⁵ 1./kg。当添加碱金属阳离子时，聚醚泡沫中铂的萃取百分比按K⁺ < Na⁺ < Li⁺的顺序增加，而聚酯泡沫中按K⁺ > Na⁺ > Li⁺的顺序降低。此外，随着泡沫中聚环氧乙烷比例的增加，吸附效率提高。Scatchard图分析表明，聚醚泡沫中松散结合的铂与紧密结合的铂的比例为2:1，然而，实验结果与作为主要吸附方法的弱碱阴离子交换机制一致。对于聚酯泡沫，结果与类溶剂离子对吸附机制一致。
