摘要
酸在氢型阳离子交换树脂柱上的分离机理已有研究,Glod等根据离子排斥色谱中的Donnan膜平衡,推导出分配系数K_d与酸离解常数K_a的关系,能大致预测酸的流出顺序,但不能说明为什么pK_a极为相近的有机酸却有较大的保留时间差别.Bafna等从分子吸附的角度考察了某些有机酸在阳离子交换树脂上的吸附平衡和洗脱行为.
The adsorption effects in ion-exclusion chromatographic separation of formic, acetic,propionic, iso-butyric, butyric, iso-valeric and valeric acids have been studied. It isassumed that both Donnan membrane equilibrium and adsorption equilibrium are involvedin chromatographic process. Thus, the following equation expressing the distribution coef-ficient, K_d, can be derived when water is used as an eluent: K_d=(K+1){[1+4(2+K)C/K_a]^(1/2)-1)/(2K+3+[1+4(2+K)C/K_2]^(1/2))where K, K. and C are adsorption equilibrium constant, dissociation constant and acid con-centration at peak maximum respectively.The adsorption equilibrium constants of some fatty acids are estimated from the reten-tion data. Linear relationship between lnK and topological parameters, ~1x are observed.
出处
《应用化学》
CAS
CSCD
北大核心
1989年第2期95-98,共4页
Chinese Journal of Applied Chemistry
关键词
离子排斥色谱
脂肪酸
吸附作用
Ion-exclusion chromatography
Aliphatic acids
Adsorption
