SEC Separation of Polysaccharides Using Macroporous Spherical Silica Gel as a Stationary Phase

Abstract

Meso- and macroporous spherical silica gels of pore sizes in the range of 60–1000 Å and 40–75 µm particle size were investigated as a stationary phase for the separation and purification of polysaccharides and poly(ethylene glycols) (PEGs) of various MWs using an aqueous mobile phase. Sephadex and Bio-Gel were used for comparison as the most common stationary phases for similar purposes. The separation of dextrans of a mean MW = 31 kDa from small molecules (NaCl) was possible with SiO2 with a pore size of 60–300 Å, but the observed efficiencies of a column of the same size were lower comparing with Sephadex or Bio-Gel. In the case of oxidized alginic acid only SiO2 of the 60 Å pore size was suitable, while Sephadex, Bio-Gel and other investigated silicas were not efficient. Sephadex and 300–1000 Å SiO2 offered the possibility of dividing dextrans with MW within the range of 1 MDa–10 kDa into fractions of various MWs, while Bio-Gel and 60 Å SiO2 were not suitable. The investigated silica gels strongly adsorbed PEGs of MW 2–20 kDa. The amount adsorbed decreased with the increase of pore size and they were not useful as a stationary phase for this class of polymers. An advantage of SiO2 of the investigated particle size was a very low back pressure comparing with Sephadex. A considerably lower price of silica offers time- and cost-efficient separation of polysaccharides.Graphical Abstract

Methods in food science and technology. Part 1

“…Hyaluronic acid is obtained from rooster combs by extraction with sodium acetate and precipitation with an ethanol solution. Dextran is now synthesized by lactic acid bacteria, such as Leuconostoc mesenteroides using sucrose [Krawczyk et al 2018].…”

“…For technological, biochemical, and medicine-related applications it is also important to separate a particular fraction of a polysaccharide with a suitable molar mass. For example, 200 000-2 000 000 g/mol fractions of inulin, β-glucan, levan, and hyaluronic acid are usually used for pharmaceutical-related purposes [Krawczyk et al 2018]. One of the reasons is molar mass dependent properties of polysaccharides.…”

“…Therefore, methods of purification from natural sources and separation of polysaccharides into fractions of a particular molar mass suitable for analytical and preparative purposes are necessary. The most commonly used methods are: capillary electrophoresis (CE), a combination of CE and HPLC, nanofiltration, and SEC [Hong et al 2012;Krawczyk et al 2018].…”