Composite dextran gels as size exclusion chromatography stationary phases

Composite dextran gels have been prepared using epichlorohydrin as the covalent cross-linker and a modifying agent, typically a polyvalent metal compound creating complexes with the residual OH groups of the polymer matrix. Two series of gels were prepared and investigated by a comparison of their swellabilities in water as well as the separation characteristics when used as size exclusion chromatography (SEC) stationary phases. The gels were in situ modified with sulfates of Mg(II), Zn(II), Co(II), Ni(II), Cu(II), Mn(lI), A1(III), Fe(III) and tetraethylorthotitanate or with the oxides: MgO, ZnO, Al2O3, TiO2 and SiO2. Large differences in the swellabilities and SEC calibration dependences for poly(ethylene glycol) standards in an aqueous eluent have been found and discussed.