Adsorption Properties of the Albumin-Chromium(III) Oxide System - Effect of Solution Ph and Ionic Strength

The phenomenon of protein adsorption on solid surfaces is important in many scientific areas. It is a common process, but very complicated. In this paper, both the mechanism of BSA, HSA, and OVA adsorption on chromium( III) oxide and the structure of formed adsorption layers were determined. The adsorption process was examined as a function of solution pH and ionic strengths. Regardless of the protein type the highest adsorption level was observed when the pH value of the solution was close to the protein isoelectric point. Under these conditions the macromolecules have a compact and folded conformation that allows for the packing of a larger amount on the unit Cr2O3 surface. The minimum adsorption rate, regardless of the protein type, was observed at pH = 3. It can be related to the expanded conformation of macromolecules and the electrostatic repulsion between the positively charged Cr2O3 surface and the positively charged polymer segments. The obtained results may be very helpful in the development of removal procedure of specific substances from the sewages and wastewaters. Furthermore, this information can be used to improve the separation processes carried out in food industry.