Novel zone elution mode in coiled tube field-flow fractionation for online separation and characterization of environmental submicron particles

Coiled tube field-flow fractionation (CTFFF) is currently applied to environmental and material studies. In the present work, a novel zone elution mode in CTFFF has been proposed and developed. Zone elution mode is based on the separation of particles by stepwise decreasing the flow rate of the carrier fluid and their subsequent elution at a constant flow rate. The fractionation parameters were optimized using a mixture of standard silica submicron particles (150, 390, and 900 nm). Taking samples of volcanic ash as examples, it has been demonstrated that zone elution mode can be successfully used for the fractionation of environmental nano- and submicron particles. For the first time, CTFFF was coupled online with a dynamic light scattering detector for the size characterization of eluted particles. Zone elution in CTFFF can serve for the further development of hyphenated techniques enabling efficient fractionation and size/elemental characterization of environmental particles in nano- and submicrometric size ranges. Graphical abstract