Nucleodex

Nucleodex™ HPLC columns, manufactured by Macherey-Nagel are various cyclodextrin-modified silica phases for HPLC enantiomer separation. The base material is Machery-Nagel´s Nucleosil^® silica with 100 Å pore size. The cyclodextrins are covalently bonded to the base material via a proprietary spacer. The separation is based on hydrogen bonds and dipole interactions between functional groups of the analyte and hydroxyl groups of the cyclodextrin. For the permethylated phases, the ability to form hydrogen bonds is reduced. The phases are thus significantly more hydrophobic compared to Nucleodex™ β-OH with unmodified cyclodextrin as the chiral selector, resulting in shorter retention times. Nucleodex™ phases are especially suited for the control of optical purity, but also for semipreparative separations and for the analysis of positional and cis-trans isomers.