Field-flow fractionation

Sedimentation field flow
fractionation instrument

The development of innovative separation methods continued with support from a new three year ARC large grant on Development of new thin channel separation techniques using acoustic fields and a Monash small grant on Measurement of charge distributions of colloid particles and polyelectrolytes using electrical field-flow fractionation-multiangle laser light scattering.

Niem Tri (PhD candidate) achieved a significant breakthrough in fundamental separation science by demonstrating that a standing ultrasonic sound wave with a wavelength twice the thickness of a thin flow channel can be used to continuously separate particles such as silica, bacteria cells and yeast. A goal of this project is to develop methods for separating bacterial and algal cells from aquatic sediments.

Dr Reshmi Sharma and Jiawei Le (MSc candidate) have investigated several methods for performing size based speciation of phosphorous and metals in rivers using split thin channels. Two advances have been the use of a centrifugal field instead of gravity to extend the particle size range from 2 mm down to 0.2 mm and the successful use of the separation instrumentation in the field. An application of this technology being performed in collaboration with Dr Angus Crossnan and Professor Ivan Kennedy from University of Sydney involves determining endosulfan speciation in soil and sediment samples. 

Bailin Chen (PhD candidate) and Finlay Shanks have continued their work coupling FFF with ICP-MS to generate element concentration distributions of natural colloids. Bailin successfully automated a FFF-graphite furnace AAS hyphenated instrument. Work using these techniques to investigate the role of Fe and Mn hydrous oxide particle coatings on the association of orthophosphate and metals with soils and sediments were published during the year.