Department of Chemistry & Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
J Chromatogr A. 2012 Jun 8;1241:69-75. doi: 10.1016/j.chroma.2012.04.024. Epub 2012 Apr 17.
"Obstruction factor" is a generic rubric under which are usually gathered the interparticle, intraparticle, stationary phase, and total obstruction factors, γ(e), γ(p), γ(s), and γ(t), respectively. These, in turn, affect longitudinal diffusion and stationary, mobile phase, and stagnant mobile phase mass transfer. We conclude here our investigation into the various obstruction factors operative in size-exclusion chromatography (SEC). Stop-flow experiments were employed to determine either the interparticle (for analytes with K(SEC)=0) or the total (for analytes with K(SEC)>0) obstruction factor, and these results were combined with those from variable-flow-rate experiments which provided the intraparticle obstruction factor. Because of minimal enthalpic interactions between the analytes and stationary phase, in SEC γ(s)≈0, which allows for isolation of the other obstruction factors. A relationship between γ(t), γ(e), and γ(p) was proposed for SEC, based on previous independent work and dependent upon the various column porosities. This relationship was extended to hydrodynamic chromatography, a technique in which, ideally, both γ(s) and γ(p) are equal to zero.
“阻碍因子”是一个通用术语，通常包括相间、颗粒内、固定相和总阻碍因子，分别表示为 γ(e)、γ(p)、γ(s)和γ(t)。这些因子依次影响纵向扩散以及固定相、流动相和停滞流动相的传质。至此，我们完成了对尺寸排阻色谱（SEC）中各种阻碍因子的研究。采用停流实验来确定相间（对于 K(SEC)=0 的分析物）或总（对于 K(SEC)>0 的分析物）阻碍因子，这些结果与来自可变流速实验的结果相结合，该实验提供了颗粒内阻碍因子。由于分析物和固定相之间的焓相互作用最小，在 SEC 中 γ(s)≈0，可以分离出其他阻碍因子。基于先前的独立工作和各种柱孔隙率，提出了 SEC 中 γ(t)、γ(e)和 γ(p)之间的关系。该关系扩展到了理想情况下 γ(s)和 γ(p)都等于零的水动力色谱。
