Studies of column packings for polymer separations by size exclusion and interactive chromatography
thesisposted on 22.02.2013 by Ana M.C. Montenegro
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The chromatographic behaviour of a new column packing for high performance size exclusion chromatography based on crosslinked polyacrylamide particles was studied. Experimental retention data for poly(ethylene glycol)and poly(ethylene oxide) standards in water and water-methanol mixtures showed that the separation mechanism is size exclusion, since a universal calibration plot based on hydrodynamic volume was obtained. For polysaccharide standards in water and water-methanol (80/20), the universal calibration was valid for molecular weights above 4 * 10~. Below this value, secondary mechanisms appear to be taking part in the separation since water-methanol (80/20) is a poor solvent for polysaccharides. Crosslinked polyacrylamide packings showed an interactive behaviour with tetrahydrofuran and dimethylformamide as eluents with polystyrene and poly( ethylene glycol )/poly(ethylene oxide) standards and the universal calibration was not valid....