色谱柱分离过程的驰豫理论——溶质非平衡线性分配流出曲线的特征

Relaxation Theory in GC——The Profile in Linear Non Equilibrium Condition

假设溶质在两相间非平衡线性分配 ,根据色谱柱分离过程驰豫理论的基本模型 ,得到了反映各输运参量与流出曲线间关系的卷积形式表达式。采用统计矩的方法加以研究 ,说明了在柱效较低、流动相线速较快时可能出现的峰分裂现象。研究结果也表明 ,在线性色谱的情况下 。

When the isotherm is linear, each molecule behaves independently to the others, and the molecular dynamic problem of substances through a chromatographic column can be investigated with the retardation theory of GC. The transfer can be divided into two parts, one is due to the transform of the mobile phase, and the other is the transform between the stationary phase and the mobile phase due to the different rate constants. The profile is theoretically derived, which is a convolution of a Poisson function and the Giddings’s result from the random walk model. There are two maximum in the profile, one at the retention time, and the other at dead time. Generally, the peak at the dead time is much smaller than the others, and can’t be detected. So one sample is one peak on the chromatographic figure. But, in the special condition the column is short enough, or the speed of mobile phase is fast enough, two peaks can be found i.g. first term splitting. The moments also are used to discuss the effluence of the transfer parameters on the profile. The results show the effect of the transfer rate constants on the peak spreading is almost reverse to the speed of the mobile phase, and the symmetry of profile rise with k a.