title: Comparison of analytical and semi-preparative columns for high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance.
abstract: The application of analytical and semi-preparative columns in reversed-phase liquid chromatography-solid-phase extraction-nuclear magnetic resonance (HPLC-SPE-NMR) was compared. The work was aiming at separating a higher sample amount in a single run and in this way to reduce the necessary NMR measurement time of separated compounds. Several parameters for compound separation and trapping procedures were optimised: flow rate of HPLC and make-up water pumps, choice of stationary phase cartridges and drying time. The separation and loadability of nine model compounds on analytical and semi-preparative columns was determined, as well as the focussing capacity of SH-type SPE cartridges. It was found that a semi-preparative column--or multiple peak trapping on analytical columns--gave better results than a standard 4.6mm analytical column for non-polar compounds (e.g. flavonoid aglycones, sesquiterpene lactones, non-polar terpenes, logP>2), but for polar compounds (logP<-2) did not offer any advantage over an analytical column, or was even disadvantageous. For intermediately polar compounds (-2<logP<2) this has to be investigated per compound.
authors.affiliation: Laboratory of Organic Chemistry, Natural Products Chemistry Group, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands. giedrius.miliauskas@wur.nl
authors.forename: Giedrius
authors.initials: G
authors.lastname: Miliauskas
authors.forename: Teris A
authors.initials: TA
authors.lastname: van Beek
authors.forename: Pieter
authors.initials: P
authors.lastname: de Waard
authors.forename: Rimantas P
authors.initials: RP
authors.lastname: Venskutonis
authors.forename: Ernst J R
authors.initials: EJ
authors.lastname: Sudhölter
mesh_terms: D000678:Amygdalin / Q000032:analysis; D002110:Caffeine / Q000032:analysis; D005591:Chemical Fractionation / Q000295:instrumentation* / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods*; D005707:Gallic Acid / Q000032:analysis; D005961:Glucosinolates / Q000032:analysis; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D009822:Oils, Volatile / Q000737:chemistry; D028321:Plant Preparations / Q000032:analysis*
chemical_list: D005961:Glucosinolates; D009822:Oils, Volatile; D028321:Plant Preparations; D000678:Amygdalin; D002110:Caffeine; C010330:sinigrin; D005707:Gallic Acid