Selectivities of polymer encapsulated stationary phases

Silanol groups have always been a matter of concern in the separation of polar solutes with chemically modified stationary phases. Various ways of silica modifications have been discussed. By copolymerization of vinyl modified silica or alumina with olefinic organics stationary phases with improved stability and performance for the separation of basic solutes, peptides and proteins can be prepared in a reproducible way. The stability of these polymer encapsulated stationary phases is superior to that of conventional silanized stationary phases in respect of column life time at high pH values. By modification of the olefinic compound cation and anion exchanger, polar stationary phases for SEC and HIC of proteins, and chiral phases of high enantio selectivity have been prepared