By Aqueous Biphasic Extraction Chromatography ABEC

In classical solvent extraction, it is often inconvenient for the extracted species to remain in the solvent phase and it is usual to back-strip into a fresh aqueous phase. This may often be achieved in some simple fashion, such as by reduction or, more commonly, by change in pH to produce a charged moiety that is now more soluble in the aqueous phase. In such cases, albeit after suitable clean-up, spent solvent may usually be recycled and reused, if necessary, after distillation. For ABS, this...

Determination of the Binodal

By convention, the component predominantly in the bottom phase is plotted as the abscissa and the component predominantly in the top phase is plotted as the ordinate. The three methods are illustrated graphically in Fig. 2 (see Note 4). 1. In test tubes, using the appropriate stock solutions, prepare systems with different compositions of known weight. Account for the additional volume owing to titration, e.g., if 5 g systems are prepared, 10 mL test tubes should be used (see Note 5). As an...

References

Asenjo, J., Parrado, J., and Andrews, B. (1991) Rational design of purification processes for recombinant proteins. Ann. NY Acad. Sci. 646, 334-56. 2. Albertsson, P.-A. (1967) Two-phase separation of viruses. Meth. Virol. 2,303-321. 3. Philipson, L. (1969) Aqueous polymer phase systems in virology, in Fundamental Techniques in Virology (Habel, K. and Salzman, P., eds.), Academic, New York, pp. 109-128. 4. Albertsson, P.-A. (1974) Concentration of virus by phase partition. Water Resources Symp....

Separation of Metal Ions Using an ABEC Column

Weigh out ca. 0.5 g of the ABEC resin prepared as outlined in Subheading 2.2.1., item 1. 2. Suspend the resin in ca. 30 mL of deionized water in a 50-mL beaker. 3. Sonicate the sample for 20 min to break up any clumps to facilitate packing the column. 4. Slurry pack the suspended resin into a small glass chromatography column. 0.5 g of resin will yield a bed height of about 2 cm in a column of the currently suggested dimensions. 5. Place a small filter frit 0.45- m pore size on top of the...

Torsten Minuth 1 Introduction

Extraction systems based on nonionic surfactants have been described as an alternative to the standard polymer polymer or polymer salt systems. Phase-forming surfactants are, for example, the nonionic polyoxyethylene-type detergents. This kind of aqueous two-phase system ATPS is simply induced by a switch in the temperature on the basis of the temperature-dependent reversible hydration dehydration of the polar ethylene oxide headgroups. A single isotropic micellar phase separates into two...

Notes

Polymers PEG, a linear synthetic polymer of ethylene oxide units, and Dx, poly a-1,6-glucose , are the most commonly used polymers in the preparation of aqueous two-phase systems. Examples of other sugar polymers used are Ficoll polysucrose , pullulan and maltodextrins besides use of some derivatized carbohydrate polymers has also been reported including methylcellulose, hydroxyethylcellulose HEC , Reppal PES hydroxypropyl starch , benzoyl-dextran, dextran sulfate, and diethylaminoethyl DEAE...