The dynamics of adsorption of the Leu-Leu stereoisomers in a chromatographic column packed with the Chirobiotic R chiral stationary phase bearing grafted antibiotic ristocetin A was studied by means of measurement and analysis of van Deemter plots. Similar measurements were carried out with weakly retained Gly-Gly for the sake of comparison. The bulk diffusion coefficients of the investigated dipeptides were also determined. It is found that the van Deemter plots of both the Leu-Leu stereoisomers and Gly-Gly have an uncommon convex-upward shape. Besides, the van Deemter B coefficients for the Leu-Leu stereoisomers, but not for Gly-Gly, have unusually high values. It is suggested that a high transcolumn contribution to eddy dispersion, which turned out to be enantioselective, accounts for these findings. Adsorption kinetics of all the dipeptides considered is relatively slow, the adsorption rate constant (k_ads) being of order of magnitude 20–60 s⁻¹. k_ads does not depend on the configuration of Leu-Leu stereoisomers, although their affinity toward the chiral selector depends on this factor. This supports the above hypothesis that eddy dispersion is mainly responsible for the observed peculiarities in the dynamic behavior of dipeptides, and adsorption kinetics has secondary importance in this phenomenon.

通过对van Deemter图的测量和分析，研究了Leu-Leu立体异构体在装有Chirobiotic R手性固定相的接枝抗生素克里斯托菌素A的色谱柱中的吸附动力学。为了比较，在保留力弱的Gly-Gly上进行了类似的测量。还确定了所研究的二肽的体积扩散系数。发现Leu-Leu立体异构体和Gly-Gly的van Deemter图均具有罕见的凸向上形状。此外，范Deemter BLeu-Leu立体异构体的系数（而不是Gly-Gly的系数）具有异常高的值。有人认为，对涡流扩散的高跨柱贡献（事实证明是对映选择性的）解释了这些发现。所考虑的所有二肽的吸附动力学都相对较慢，吸附速率常数（k _ad）约为20-60 s ^-1数量级。k个_广告尽管它们对手性选择剂的亲和力取决于该因素，但它并不取决于Leu-Leu立体异构体的构型。这支持了上述假设，即涡旋弥散主要是所观察到的二肽动力学行为的特征，而吸附动力学在该现象中具有次要重要性。