title: Effects of solvent on chiral and enantiomeric separation of Koga bases using derivatized amylose chiral stationary phase.
abstract: The separation of R,R-, S,S-, and meso-Koga bases on derivatized amylose chiral stationary phases (CSP) has been studied using different alcohol and alcohol-hexane mixtures as eluant. Straight-chain and branched alcohols with carbon numbers from one to four were investigated. The carbon number and geometry of the alcohol impacts the separation of Koga bases. The optimal separations were obtained using a mixture of methanol with linear or branched alcohol. Also, the elution order of meso- and R,R-Koga base was switched as content of branched alcohol increases in cosolvent. The study of acidic and basic additive effects demonstrated that maintaining analytes in the free base state is crucial in order to achieve retention and separation. TEA alone or TEA and TFA mixture were used in the studies.
authors.affiliation: Analytical Research and Development, Amgen, Inc., Thousand Oaks, California 91320, USA. gguo@amgen.com
authors.forename: Hong-Xun
authors.initials: HX
authors.lastname: Guo
authors.forename: Steven
authors.initials: S
authors.lastname: Wu
authors.forename: Kelly
authors.initials: K
authors.lastname: Nadeau
authors.forename: George A
authors.initials: GA
authors.lastname: Moniz
authors.forename: Sebastian
authors.initials: S
authors.lastname: Caille
mesh_terms: D000143:Acids / Q000737:chemistry; D000468:Alkalies / Q000737:chemistry*; D000688:Amylose / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000143:Acids; D000468:Alkalies; D012997:Solvents; D000688:Amylose