title: Application of diaza-18-crown-6-capped beta-cyclodextrin bonded silica particles as chiral stationary phases for ultrahigh pressure capillary liquid chromatography.
abstract: Two bonded chiral stationary phases (CSPs), 8-aminoquinoline-2-ylmethyl- and 8-aminoquinoline-7-ylmethyl-diaza-18-crown-6-capped [3-(2-O-beta-cyclodextrin)-2-hydroxypropoxy]propylsilyl silica particles (non-porous, 1.5 microm), have been prepared and evaluated using capillary liquid chromatography at high pressures (> or = 8000 p.s.i.). High column efficiency (up to 400 000 plates m(-1)) was achieved for chiral separations. These CSPs with two recognition sites, i.e. substituted-diaza-18-crown-6 and beta-cyclodextrin combined with high chromatographic efficiency provide good resolution of a variety of enantiomers and positional isomers in relatively short times under reversed-phase conditions. After inclusion of a Ni (II) ion from the mobile phase, the positively charged crown ether-capped beta-cyclodextrin facilitates specific static, dipolar, and host-guest complexation interactions with solutes.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
authors.forename: Yinhan
authors.initials: Y
authors.lastname: Gong
authors.forename: Yanqiao
authors.initials: Y
authors.lastname: Xiang
authors.forename: Bingfang
authors.initials: B
authors.lastname: Yue
authors.forename: Guoping
authors.initials: G
authors.lastname: Xue
authors.forename: Jerald S
authors.initials: JS
authors.lastname: Bradshaw
authors.forename: Hian Kee
authors.initials: HK
authors.lastname: Lee
authors.forename: Milton L
authors.initials: ML
authors.lastname: Lee
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D043844:Crown Ethers / Q000737:chemistry*; D003505:Cyclodextrins / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D047392:beta-Cyclodextrins
chemical_list: D001372:Aza Compounds; D043844:Crown Ethers; D003505:Cyclodextrins; D047392:beta-Cyclodextrins; D012822:Silicon Dioxide; C031215:betadex