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Sun X.,Chinese Academy of Fishery Sciences | Sun X.,National Center for Quality Supervision and Test of Aquatic Products | Xu J.,Chinese Academy of Fishery Sciences | Zhao X.,Hubei University of Medicine | And 3 more authors.

Due to the synthetic flexibility and special enantioselectivity, chiral ionic liquids (CILs) have heightened interest and an increasing number of CILs has been designed and utilized. In this work, CIL named l-1-butyl-3-(2- propionic-1-ether) imidazolium bromide ([BAlaIM]Br) derived from natural amino acids was synthesized, with chiral center at cation moiety. Chiral stationary phases for gas chromatography were then prepared by mixing the CIL with polymeric ionic liquid ([PSOMIM][NTf2], homemade) at different ratios (4:1, 2:1, and 1:1). The column efficiency was measured to be about 3,200 plates m-1 (8 m × 0.25 mm i.d.) when the content of [BAlaIM]Br was 50 % (mass percent) in the mixed stationary phase. All columns were coated via the static coating method using 0.30 % (w/v) of stationary phases dissolved in methanol. The results showed that the CIL contributed to the selectivity of stationary phase toward positional isomers dichlorobenzenes, methylnaphthalenes and pinenes, etc. Meanwhile, [BAlaIM]Br showed better selectivity for enantiomers such as carvones, citronellals, limonenes and camphors. The interactions between chiral selector and enantiomers were also discussed. © 2013 Springer-Verlag Berlin Heidelberg. Source

Sun X.,Chinese Academy of Fishery Sciences | Sun X.,National Center for Quality Supervision and Test of Aquatic Products | Xing J.,Wuhan University | Zhai Y.,Chinese Academy of Fishery Sciences | And 3 more authors.
Progress in Chemistry

In this paper, the development of ionic liquids as stationary phases for gas chromatography is briefly described. In order to improve the thermal stability, selectivity and column efficiency of ionic liquid stationary phases, the synthesis methods of ionic liquid stationary phases with achiral selectivity are developed successively, including small molecule ionic liquids, bulky ionic liquids, polymeric ionic liquids, physical mixed ionic liquids and chemically bonded ionic liquids. Meanwhile, ionic liquids are applied in chiral gas chromatography, employed as the solvent of chiral selectors or as chiral stationary phases of gas chromatography. Chiral pools of these ionic liquids are mostly from amino acids, chiral amines and bonded cyclodextrins. The differences in selectivity of these ionic liquid stationary phases are also discussed and reviewed. Then, the application of ionic liquids in two-dimensional gas chromatography and fast gas chromatography are introduced. Finally, the synthesis and application of ionic liquids in gas chromatography are summarized. The prospects of ionic liquid as novel separation materials are also discussed and forecasted. Source

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