Enantioseparation of chiral β-blockers using polynorepinephrine-coated nanoparticles and chiral capillary electrophoresis.

A method of combining magnetic solid-phase separation (MSPE) and chiral capillary electrophoresis (CE) is developed for enantioseparation of trace amounts of β-blockers. Polynorepinephrine-functionalized magnetic nanoparticles (polyNE-MNPs) are synthesized and applied to simultaneously extract three β-blockers (carteolol, metoprolol, and betaxolol). The prepared polyNE-MNPs are spherical with a diameter of 198 ± 17 nm and the thickness of the polyNE coating is about 14 nm. PolyNE possesses abundant catechol hydroxyl and secondary amine groups, endowing the MNPs with excellent hydrophilicity. Under the optimum conditions, the extraction efficiencies of polyNE-MNPs for β-blockers are in the range of 89.6 to 100%, with relative standard deviations (RSDs) below 3.5%. The extraction process can be finished in 4 min. Field-enhanced sample injection (FESI) in chiral CE is constructed to further enhance the sensitivities of β-blocker enantiomers. The limits of detection for β-blocker enantiomers by the FESI-CE with polyNE-MNPs are in the range of 0.401 to 1.59 ng mL. The practicability of this method in real samples is evaluated by analysis of human urine samples. The recoveries for each enantiomer of β-blockers in the real samples range from 89.5 to 92.8%, with RSDs ranging from 0.37 to 5.9%. The whole detection process can be finished in less than 0.5 h. The method demonstrates its great potential in the pharmacokinetic and pharmacodynamic studies of chiral drugs in humans. Graphical abstract ᅟ.