丙酮酸化学萃取的盐效应

以三辛胺为萃取剂，在不同离子类型及离子强度下对丙酮酸的络合萃取过程进行了研究。结果表明，在一定pH范围内，随无机离子浓度的增加，丙酮酸分配系数随盐浓度的增加而迅速降低；萃后水相pH随盐浓度的增加均有不同程度的升高，在同一离子强度下，萃取剂浓度越高，萃后水相pH上升幅度越大。红外光谱的分析结果证实了无机阴离子可能通过同离子竞争，抑制了丙酮酸根离子与络合剂的离子对缔合作用，从而降低了萃取效果。

Salt Effect in Organic Solvent Extraction of Pyruvic Acid

Tri-n-octylamine was selected as the extractant and a series of extraction equilibrium experiment for pyruvic acid with TOA dissolved in n-octanol were carried out under various ion types and strengths in this paper. The effects of both salt and TOA concentrations on extraction distribution ratio were discussed in detail. At pH 1.14, distribution ratio D decreases sharply with the increase of salt concentration and the pH of aqueous phase increases also after extraction. At the same ion strength, the higher TOA concentration is, the wider extent pH changes. The opinion that ion-pair association was weakened by ion competition was confirmed by infrared spectra, and the efficiency of extraction was suppressed as a result.