Evaluation of novel dendrimer chiral stationary phases using HPLC

The reversed phase chromatographic properties of the [G1]-L-glutamic acid e thyl ester-AC-silica (1), [G2]-L-glutamic acid ethyl ester-AC-silica (2) an d the [G1]-L-glutamic acid t-butyl ester-AC-silica (3) dendrimer stationary phases were evaluated. initial studies involved the comparison between the se phases with a classic reversed phase (i.e. ODS1) by the separation of a standard reversed phase test mixture composed of dimethylphthalate, nitrobe nzene, anisole, diphenylamine and fluorene. Separations were achieved with comparable performance to those obtained with the conventional reversed pha se (ODS1). However, it was apparent that he chromatographic selectivity exh ibited by the dendrimer stationary phases was different from that of the OD S1 phase. On a per mole basis the dendrimers exhibited similar land sometim es greater) affinity for these analytes compared with the ODS1 ligand. Subs equent chromatographic experiments were conducted upon the dendrimer chiral stationary phases using chiral analytes under reversed phase and normal ph ase conditions. Chiral resolution was not observed.