Monolithic silica columns with chemically bonded tert-butylcarbamoylquinine chiral anion-exchanger selector as a stationary phase for enantiomer separations

Abstract

An enantioselective silica rod type chiral stationary phase (CSP) is presented as a novel combination of the well-known enantiomer separation properties of immobilized tert-butyl-carbamoylquinine chiral anion-exchanger selector with the unique properties of monolithic silica material. The chromatographic behavior of the tert-butyl-carbamoylquinine silica rod was studied and compared with a similar prepared particulate material. Good selectivities were achieved for a spectrum of chiral test components like N-derivatized amino acids (DNB- Ac-, DNZ-, Bz-, Z-amino acids) and for Suprofen. The influence of mobile phase parameters, as well as the effect of serially coupling up to six 10 cm monolithic silica columns was studied and put in context to conventional columns of particulate 5 μm type CSP. Using that 60 cm long monolithic column it was possible to improve the enantiomer separation of Suprofen and achieve a baseline separation in less than 10 min of total separation time.