Continuous Multicomponent Focusing of Solutes and Particles Using Spatially Stabilized pH

本研究建议使用磁稳定流化床 床（MSFB）以分离两性离子分子（即，分子 含有带负电荷和带正电荷的部分）， 由于等电点不同（即，时的pH 分子不带电）。 流化床由一个 添加带负电荷的树脂颗粒的管 从管的顶部，并且流化液体是 从底部分布。 去除颗粒， 底部，和液体从顶部允许连续 操作 通过以下方式在床中保持pH梯度： 在高pH下加入液体进料， 含有溶解溶质的混合物（ 作为分离的目标）被供给到液体中 在靠近底部的地方，流到一边， 柱 当溶质在床层中向上移动时， 液体运动，溶质所暴露的局部pH值 减少。 局部pH值的降低导致溶质 最终变成带正电的（在 在局部pH值相等的位置上方的床 与溶质的等电位值相关）。 一旦积极 带电荷，溶质静电结合到负离子上， 带电荷的树脂，并与树脂颗粒一起携带， 列的底部。 当它沿着列下降时， 局部pH值下降，这导致溶质逆转其 充电，从树脂颗粒中去除自身，并成为 夹带在向上流动的液体中。 溶质因此变成 被困在塔中某一水平的狭窄区域中， 局部pH等于溶质的等电点。 理想情况下， 混合物中的溶质会分成不同的区域 在柱中占据不同的水平。 通过撤回 流体和固体从这些区域，液体富含一种溶质 从而实现分离。 的 拟议的研究将开发一个工作原型， 床的有效性，以准备分离 生物分子

This study proposes using a magnetically stabilized fluidized bed (MSFB) to separate zwitterionic molecules (i.e., molecules containing negatively and positively charged moieties) by virtue of differing isoelectric values (i.e., the pH at which the molecule is not charged). The fluidized bed consists of a tube in which negatively charged resin particles are added from the top of the tube, and the fluidizing liquid is distributed from the bottom. Removal of the particles from the bottom, and liquid from the top allows for continuous operation. A pH gradient is maintained in the bed by inserting the liquid feed at a high pH and the solid particles at a low pH. A mixture containing dissolved solutes (one of which is targeted for separation) is fed into the liquid stream somewhere near the bottom, and to one side of the column. As the solute moves up the bed by virtue of the liquid motion, the local pH that the solute is exposed to decreases. The reduction in the local pH causes the solutes to eventually become positively charged (at the positions in the bed just above the positions where the local pH is equal to the isoelectric values of the solutes). Once positively charged, the solute binds electrostatically to the negatively charged resin, and is carried with the resin particles down to the bottom of the column. As it descends down the column, the local pH decreases, and this causes the solute to reverse its charge, remove itself from the resin particle, and become entrained in the upflowing liquid. The solute thus becomes trapped in a narrow zone at a level in the column where the local pH is equal to the solute's isoelectric point. Ideally, the solutes in the mixture will separate out into zones occupying different levels in the column. By withdrawing fluid and solid from these zones, liquid rich in one solute can be obtained, thereby effecting the separation. The proposed research will develop a working prototype, and scope the effectiveness of the bed to prepare separations of biological molecules.