THE INFLUENCE OF LOW-MOLECULAR SUBSTANCES ON THE PHASE SEPARATION CAPACITY OF A TWO-PHASE PEG – SODIUM CITRATE – WATER SYSTEM

As is known, two-phase polymer-polymer-water and polymer-electrolyte-water systems (SPIS) are widely used in the separation and purification of biological objects in biotechnology and pharmacology, as well as in the quality control of medicinal products. Depending on the nature of these processes, it is important to purposefully change the separation capacity of SPIS. The aim of the presented research is to ensure that it is adapted to each application object by using different additives to separate and purify biological objects. The presented study investigated the phase diagrams of the water-polymer two-phase system PEG - sodium citrate - water in the presence of certain additives. The influence of additives on the separating ability of the two-phase system PEG - sodium citrate - water was determined. Analysis of the provided data shows that the variation in the parameters of the phase diagram and the different values of the separating ability n* of the two-phase system depending on the nature of the additives is associated with changes in the structure of water under the influence of these factors. This leads to changes in the interaction of the phase-forming components of the two-phase system with water, resulting in differences in the physicochemical properties, particularly the relative hydrophobicities of the two-phase system.