Postnova AF 2000 aF4
Asymmetric Flow FFF is a subcategory of Flow FFF.
In Asymmetric Flow FFF the separation force is generated by a cross flow field inside the channel. The cross flow is divided from the main flow, pumped through the channel and is directed through a semi-permeable membrane which is located at the bottom wall. The membrane pores size prevents the sample to pass through but allows the solvent to exit the channel easily. The sample fractions are eluted out of the channel in direction to the detectors by the remaining channel flow.
In our group we use the aF4 to overcome the limitations of batch DLS by first separating the particle on size before measuring the Rg and Rh of the distribution. This results in e true particle size distribution and combined it gives structural information (sphere, ros, hollow spere etc. Combining it with UV, Fluorescence and fractionating power an unique total solution can be given.
More analysis can be done like protein aggregation studies and polymer mass determination.