https://doi.org/10.1351/goldbook.09931
Flow field-flow fractionation in which only one channel wall is permeable, meaning there is one channel inlet for the flow during the run and some of the channel flow is directed through the accumulation wall.
Notes:
- In a uniform width channel this would result in the channel flow decreasing dramatically along the channel length. In order to minimize this, a trapezoid shape of the separation channel has been developed for AsFlFFF. In general, the channel geometry significantly affects the separation efficiency in AF4.
- Three different channel designs were evaluated using polystyrene latex nanoparticles. The channel breadth was held constant for one (rectangular) profile, and was reduced either linearly (trapezoid profile) or exponentially (exponential profile) along the length for the other two channels. Com-pared with a rectangular channel, trapezoid and exponential profiles provided better performance of AsFlFFF and allowed band broadening to be reduced.
- Advantages of AsFlFFF include that the upper channel wall can be made of a transparent material, allowing the accumulation and sample migration to be viewed. Sample focusing can be achieved during relaxation, resulting in a narrower sample band being produced, resulting in lower band broadening.