Recovery of small bioparticles by interfacial partitioning

In this article, a qualitative study of the recovery of small bioparticles by interfacial partitioning in liquid-liquid biphasic systems is presented. A range of crystallised biomolecules with varying polarities have been chosen such as glycine, phenylglycine and ampicillin. Liquid-liquid biphasic systems in a range of polarity differences were selected such as an aqueous two-phase system (ATPS), water-butanol and water-hexanol. The results indicate that interfacial partitioning of crystals occurs even when their density exceeds that of the individual liquid phases. Yet, not all crystals partition to the same extent to the interface to form a stable and thick interphase layer. This indicates some degree of selectivity. From the analysis of these results in relation to the physicochemical properties of the crystals and the liquid phases, a hypothetical mechanism for the interfacial partitioning is deduced. Overall these results support the potential of interfacial partitioning as a large scale separation technology.