Monolithic column incorporated with lanthanide metal-organic framework for capillary electrochromatography

A new lanthanide metal-organic frameworks NKU-1 have successfully incorporated into poly (BMA- co -EDMA) monolith and evaluated by capillary electrochromatography (CEC). Lanthanide metal-organic frameworks [Eu 2 (ABTC) 1.5 (H 2 O) 3 (DMA)] (NKU-1) were synthesized by self-assembly of Eu(III) ions and 3,3′,5,5′-azo benzene tetracarboxylic acid ligands have been fabricated into poly(BMA- co -EDMA) monoliths. 1-Butyl-3-methylimidazolium tetrafluoroborate and N , N -dimethylformamide were developed as binary porogen obtaining homogeneous dispersibility for NKU-1 and high permeability for monolithic column. The successful incorporation of NKU-1 into poly(BMA- co -EDMA) was confirmed and characterized by FT-IR spectra, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer area scanning, and transmission electron microscopy. Separation ability of the NKU-1-poly (BMA- co -EDMA) monoliths was demonstrated by separating four groups of analytes in CEC, including alkylbenzenes, polycyclic aromatic hydrocarbon, aniline series and naphthyl substitutes. Compared with bare monolithic (column efficiency of 100,000   plates/m), the NKU-1-poly (BMA- co -EDMA) monoliths have displayed greater column efficiency (maximum 210,000   plates/m) and higher permeability, as well as less peak tailing. The results showed that the NKU-1-poly (BMA- co -EDMA) monoliths are promising stationary phases for CEC separations.