Development of a universal separator: Characterization of macromolecular and particulate material by aqueous and nonaqueous flow FFF at ambient and elevated operating temperatures

A flow field-flow fractionation (flow FFF) system was developed that has the unique ability to separate macromolecular and particulate material using aqueous or nonaqueous carrier liquids at ambient or elevated channel temperatures. This robust and highly versatile instrument has been used to separate sample components with a variety of carriers including THF, toluene, xylene, heptane, cyclohexane, isooctane, and water. The carrier is changed by simply flushing the channel with liquids of appropriate miscibility until the desired carrier is reached. The operating temperature is regulated by an oven that encloses the flow FFF channel. There are two main benefits of elevated temperatures in flow FFF: 1) an increase in solubility, permitting the analysis of samples that require high temperatures to dissolve; and 2) an enhancement in separation performance by the reduction in nonequilibrium band broadening due to the decrease in sample diffusivity. © 1998 John Wiley & Sons, Inc. J Micro Sep10: 75–78, 1998