The effects of pH on the partitioning of aromatic acids in a polyethylene glycol/dextran aqueous biphasic system

ABSTRACT

Distribution ratios of acidic, neutral, and basic compounds were determined in polyethylene glycol (PEG)-6000/Dextran-75000 aqueous biphasic systems (ABSs) at incremental pH values. The nature of the solute species present at each pH was identified using speciation diagrams, and it was determined that the distribution ratios were related to their charge, with maximum distribution to the upper PEG-rich phase when the neutral species were dominant. The results suggest that this ABS is tunable with simple modifications of pH leading to increasing selectivity for specific target solutes.

KEYWORDS:

• Aqueous biphasic system
• aromatic acids
• pH effect
• polyethylene glycol
• dextran

Funding

This research was supported by the Division of Chemical Sciences, Geosciences, and Bioscience, Office of Basic Energy Sciences, US Department of Energy (Grant Number DE-FG-02-96ER14673). This research was undertaken, in part, thanks to funding from the Canada Excellence Research Chairs Program.

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Additional information

Funding

This research was supported by the Division of Chemical Sciences, Geosciences, and Bioscience, Office of Basic Energy Sciences, US Department of Energy (Grant Number DE-FG-02-96ER14673). This research was undertaken, in part, thanks to funding from the Canada Excellence Research Chairs Program.