Novel restricted access chiral stationary phase synthesized via atom transfer radical polymerization for the analysis of chiral drugs in biological matrices

摘要

A new restricted access chiral stationary phase was designed and synthesized via atom transfer radical polymerization (ATRP ). Surface modified bi-functional silica with chiral selector in the inner layer and hydrophilic external layer was prepared by taking advantage of the controlled/living property of the ATRP method. ATRP initiator bound porous silica was synthesized to perform surface initiated polymerization . The chiral stationary phase was then synthesized by grafting poly(glycidyl methacrylate) (pGMA) on the surface of the silica through “grafting from” polymerization followed by β-cyclodextrin (β-CD) immobilization. On the surface of this β-CD immobilized material, the external pGMA layer was synthesized via second round ATRP using the initiator on the material. The hydrophilic structure was formed after the hydrolysis , which created a diffusion barrier for proteins . The new chiral restricted access material (chiral-CD-RAM) was characterized and its abilities for chiral separation and protein exclusion were evaluated. The result demonstrates that enantio-separations can be achieved for several drugs in HPLC using chiral-CD-RAM as stationary phase . Meanwhile, good protein recovery has been obtained. It indicated that this chiral-CD-RAM can be used for determination of certain chiral drugs in biological samples with direct injection in the HPLC analysis.