Department of Chemistry, Yonsei University, 262 Seongsanro, Seodaemun-gu, Seoul 120-749, South Korea.
J Chromatogr A. 2010 Jun 11;1217(24):3876-80. doi: 10.1016/j.chroma.2010.04.021. Epub 2010 May 2.
The separation efficiencies of three different asymmetrical flow field-flow fractionation (AF4) channel designs were evaluated using polystyrene latex standards. Channel breadth was held constant for one channel (rectangular profile), and was reduced either linearly (trapezoidal profile) or exponentially (exponential profile) along the length for the other two. The effective void volumes of the three channel types were designed to be equivalent. Theoretically, under certain flow conditions, the mean channel flow velocity of the exponential channel could be arranged to remain constant along the channel length, thereby improving separation in AF4. Particle separation obtained with the exponential channel was compared with particle separation obtained with the trapezoidal and rectangular channels. We demonstrated that at a certain flow rate condition (outflow/inflow rate=0.2), the exponential channel design indeed provided better performance with respect to the separation of polystyrene nanoparticles in terms of reducing band broadening. While the trapezoidal channel exhibited a little poorer performance than the exponential, the strongly decreasing mean flow velocity in the rectangular channel resulted in serious band broadening, a delay in retention time, and even failure of larger particles to elute.
使用聚苯乙烯乳胶标准评估了三种不同非对称流场流分离（AF4）通道设计的分离效率。一个通道的通道宽度保持不变（矩形轮廓），而另外两个通道的宽度沿长度线性（梯形轮廓）或指数（指数轮廓）减小。三种通道类型的有效空隙体积设计为等效。理论上，在某些流动条件下，可以安排指数通道的平均通道流速沿通道长度保持不变，从而改善 AF4 中的分离。用指数通道获得的颗粒分离与用梯形和矩形通道获得的颗粒分离进行了比较。我们证明，在一定的流速条件下（流出/流入速率=0.2），指数通道设计确实在减少颗粒展宽方面提供了更好的聚苯乙烯纳米颗粒分离性能。虽然梯形通道的性能略逊于指数通道，但矩形通道中平均流速的急剧下降导致严重的带宽展宽、保留时间延迟，甚至较大颗粒无法洗脱。
