Moon M H, Myers M N, Giddings J C
Department of Chemistry, University of Utah, Salt Lake City 84112.
J Chromatogr. 1990 Sep 26;517:423-33. doi: 10.1016/s0021-9673(01)95738-3.
In this article the concept of utilizing a pinched inlet channel for field-flow fractionation (FFF), in which the channel thickness is reduced over a substantial inlet segment to reduce relaxation effects and avoid stopflow, is evaluated for steric FFF using one conventional channel and two pinched inlet channels. It is shown that with the proper adjustment of flow-rate, the stopflow process in FFF can be completely avoided, thus bypassing the flow interruption associated with stopflow and reducing separation time. The maximum flow-rate that can be used for stopless flow operation without incurring zone distortion is shown to agree reasonably well with simple theory; slight departures from theory are attributed to the existence of reduced transport rates of large particles through thin channel structures.
在本文中，针对空间排阻场流分离（FFF），评估了利用收缩入口通道进行场流分离的概念。在该方法中，通道厚度在相当长的入口段内减小，以减少弛豫效应并避免停流。实验使用了一个传统通道和两个收缩入口通道。结果表明，通过适当调节流速，可以完全避免场流分离中的停流过程，从而绕过与停流相关的流动中断并缩短分离时间。在不引起区带畸变的情况下可用于无停流操作的最大流速，与简单理论相当吻合；与理论的轻微偏差归因于大颗粒通过薄通道结构时传输速率降低。
