title: Novel, fully automatic hydrophilic interaction/reversed-phase column-switching high-performance liquid chromatographic system for the complementary analysis of polar and apolar compounds in complex samples.
abstract: In this study we developed and optimized a column-switching high-performance liquid chromatographic (HPLC) system for the complementary analysis of polar and apolar compounds in complex samples. The polar compounds are separated on a hydrophilic interaction chromatographic (HILIC) column; the part of the sample non-retained on HILIC is transferred into and separated on a reversed-phase (RP) column through an interface, thus preventing the loss of analytes eluting at dead time in common single-column mode. The signals are in turn recorded in the same chromatogram either by a UV or by a mass spectrometric detector. Applying a mixture of 25 standard compounds (12 hydrophilic and 13 hydrophobic) the system proves to be reliable, robust and easy-operating. The investigation of urine revealed an increase in the detected metabolite ion masses compared to the single-column HILIC-electrospray ionization (ESI)-MS analysis. Utilizing online the complementary selectivity of HILIC and RPLC in a fully automatic mode, this approach holds out the prospect to enlarge the number of detectable compounds in non-targeted "-omics" studies and sophisticated target-driven approaches by a single injection.
authors.affiliation: National Chromatographic R. & A. Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Rainer
authors.initials: R
authors.lastname: Lehmann
authors.forename: Xin
authors.initials: X
authors.lastname: Lu
authors.forename: Xinjie
authors.initials: X
authors.lastname: Zhao
authors.forename: Guowang
authors.initials: G
authors.lastname: Xu
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet