双组分协同吸附的非线性色谱波动特征

Nonlinear chromatographic characteristics of waves in two-solute synergistic adsorption process

为了深入理解协同吸附过程的色谱规律,运用特征线法分析了双组分协同吸附色谱的3种不同类型,构造了饱和过程和洗脱过程的浓度波动图像,并与竞争吸附色谱过程做了比较.结果表明,协同吸附色谱过程的熵条件与竞争吸附情况下有很大不同;对于双组分协同吸附的3种不同类型,当强吸附组分具有或强弱吸附组分都具有协同吸附效应时,可以由特征线法得到解析解;当只有弱吸附组分具有协同效应时,色谱方程为混合型方程,特征线法失效;对饱和过程和洗脱过程的分析表明,协同效应不改变组分的分离顺序,但改变了熵条件,使得浓度波性质和波动图像随之改变.

The method of characteristics was applied to analyzing the three different types of two-solute, synergistic adsorption process in order that the chromatographic characteristics of the synergistic adsorption process could be comprehended deeply. The concentration profiles in saturation process and elution process was constructed. Comparison with the competitive adsorption process indicated that the entropy conditions of synergistic adsorption is very different; as to the three types, when strongly adsorbed solute or both of strongly and weakly adsorbed solutes had the synergistic effects, analytic solutions were obtained; however, when only weakly adsorbed solute had the synergistic effect, the method of characteristics was out of use. Moreover, simulation results of saturation process and elution process also indicated that the synergistic effect do not change the sequence of solutes flowing from the chromatogram but altered the properties and profiles of concentration waves due to the change of the entropy conditions.