title: 1H HR/MAS NMR in the suspended state: molecular recognition processes in liquid chromatography between steroids and a silica hydride-based cholesterol phase.
abstract: A mixture of eight steroids was separated by HPLC on a silica hydride-based stationary phase modified with a moiety of cholesteryl 10-undecanoate. Within the steroid mixture progesterone showed the longest retention time suggesting the strongest interaction with the stationary phase material. To obtain more detailed information upon the effective separation process, interaction studies were performed by high resolution/magic angle spinning (HR/MAS) NMR spectroscopy recorded in the suspended state. (1)H saturation transfer difference (STD) NMR experiments with T(1rho) suppression showed significant hydrophobic binding affinities of progesterone toward the cholesterol column material. These NMR results can be correlated directly to the chromatographic data obtained by HPLC.
authors.affiliation: Institute of Organic Chemistry, University of Tuebingen, Tuebingen, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Friebolin
authors.forename: Marc P
authors.initials: MP
authors.lastname: Bayer
authors.forename: Maria T
authors.initials: MT
authors.lastname: Matyska
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Pesek
authors.forename: Klaus
authors.initials: K
authors.lastname: Albert
mesh_terms: D002784:Cholesterol / Q000737:chemistry; D002788:Cholesterol Esters / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000592:standards; D008968:Molecular Conformation; D011522:Protons; D012015:Reference Standards; D017640:Silicates / Q000737:chemistry*; D013237:Stereoisomerism; D013256:Steroids / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D002788:Cholesterol Esters; D011522:Protons; D017640:Silicates; D013256:Steroids; C446044:cholesteryl-10-undecenoate; C487012:silica hydride; D002784:Cholesterol