Department of Chemistry, Hannam University, Daejeon 305-811, Korea Republic.
Nuclear Chemistry Research Center, Korea Atomic Energy Research Institute, Daejeon 305-353, Korea Republic.
Talanta. 2015 Jan;132:945-53. doi: 10.1016/j.talanta.2014.05.061. Epub 2014 Jun 10.
Retention behavior of micron-sized particles in gravitational field-flow fractionation (GrFFF) was studied in this study. Effects of ionic strength and flow rate as well as the viscosity of the GrFFF carrier liquid was investigated on the size-based selectivity (Sd), retention ratio (R), and plate height (H) of micron-sized particles using polystyrene latex beads as model particles. It was found that the retention ratio of microparticles increases with increasing flow rate or the viscosity of the carrier liquid as the particles are forced away from the accumulation wall by increased hydrodynamic lift forces (HLF). On the other hand, the retention time increases (retention ratio decreases) with increasing ionic strength of the carrier liquid at the same flow rate, due to decreased repulsive interaction between the particles and the channel accumulation wall (glass in this study) allowing the particles approach closer to the wall. Results suggest the ionic strength of the carrier liquid plays a critical role in determining retention of microparticles in GrFFF as well as the viscosity or the flow rate of the carrier liquid. It was found that the resolution and the separation time could be improved by increasing the carrier viscosity and by carefully adjusting the ionic strength of the carrier liquid.
本研究考察了微米级颗粒在重力场流分离（GrFFF）中的保留行为。使用聚苯乙烯乳胶珠作为模型颗粒，研究了离子强度、流速以及 GrFFF 载体液体的粘度对基于尺寸的选择性（Sd）、保留率（R）和板高（H）的影响。结果表明，随着颗粒所受的水动力升力（HLF）的增加，颗粒被迫远离积壁，保留率随着流速或载体液体的粘度的增加而增加。另一方面，在相同流速下，由于颗粒与通道积壁（本研究中为玻璃）之间的排斥相互作用降低，保留时间增加（保留率降低），这使得颗粒更接近壁面。结果表明，载体液体的离子强度在决定 GrFFF 中微米颗粒的保留以及载体液体的粘度或流速方面起着关键作用。研究发现，通过增加载体粘度并仔细调整载体液体的离子强度，可以提高分辨率和分离时间。
