Fabrication of chiral amino acid ionic liquid modified magnetic multifunctional nanospheres for centrifugal chiral chromatography separation of racemates

• Fe3O4@SiO2@HMDI-EMIMLpro nanospheres were fabricated for the first time.
• The materials were used as chiral selector in centrifugal chiral chromatography.
• Task-specific separation of d- and l-tryptophan was achieved completely.
• They may also be used for the chiral separation of various other racemates.

As the rapid development of nanotechnology, the magnetic nanospheres modified with special chiral selective ligands show a great potentiality in enantiomeric separation. In this study, magnetic nanospheres modified with task-specific chiral ionic liquid were designed for the separation of chiral amino acids. These modified magnetic nanospheres were effective in a direct chiral separation of five racemic amino acids (d- and l-cysteine, d- and l-arginine, d- and l-leucine, d- and l-glutamine and d- and l-tryptophan). Furthermore, a new online method for complete separation of the enantiomers via the magnetic nanospheres was established with centrifugal chiral chromatography using a spiral tube assembly mounted on a type-J coil planet centrifuge. One kind of chiral compounds, d- and l-tryptophan was resolved well using this method. These results demonstrated that the modified nanospheres display a good chiral recognition ability, and can be used as a potential material for chiral separation of various racemates.