title: Surface-crosslinked poly(3-mercaptopropyl)methylsiloxane-coatings on silica as new platform for low-bleed mass spectrometry-compatible functionalized stationary phases synthesized via thiol-ene click reaction.
abstract: A thin functional film of poly(3-mercaptopropyl)methylsiloxane was coated onto vinyl-modified silica particles (5μm, 100Å pore size) and chemically crosslinked to the surface. Excess of thiol functionalities allow bonding of alkene containing ligands by thiol-ene click reaction in a second step (QN-VII). Besides that a single step surface modification procedure was established in which alkene functional ligands were directly added to the polysiloxane coating solution and thus, after evaporation of the solvent, crosslinking to the vinylized surface and bonding of chromatographic ligand to the thiolated polysiloxane film occur simultaneously in one step (QN-VI). Successful bonding of the polysiloxane film was confirmed for both approaches by (29)Si cross-polarization/magic angle spinning NMR spectra. The new surface functionalization concept can be utilized as a new platform for the preparation of various low-bleed, mass spectrometry-compatible stationary phases with a variety of functional ligands. The concept was demonstrated by thiol-ene click reaction with quinine carbamate and its subsequent use for enantiomer separation by HPLC-UV and HPLC-ESI-QTOF-MS of acidic chiral analytes. Chromatographic enantioselectivities were similar to a comparable brush-type CSP (QN-V0). The greatly reduced background signal in LC-MS, however, comes at expense of somewhat lower chromatographic efficiencies (C-term by factor of 2 larger compared to brush-type CSP). For quantitative analysis in single reaction monitoring (MRM(HR)) in high sensitivity mode, limit of detection and limit of quantification results are comparable for both surface-polymer modified CSPs, with only slightly higher values for the conventional brush-type CSP (QN-V0).
authors: Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany.
authors: Aleksandra
authors: A
authors: Zimmermann
authors: Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany.
authors: Jeannie
authors: J
authors: Horak
authors: Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany.
authors: Adrian
authors: A
authors: Sievers-Engler
authors: Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany.
authors: Corinna
authors: C
authors: Sanwald
authors: Lindner Consulting GmbH, 3400 Klosterneuburg, Austria.
authors: Wolfgang
authors: W
authors: Lindner
authors: Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
authors: Markus
authors: M
authors: Kramer
authors: Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany. Electronic address: michael.laemmerhofer@uni-tuebingen.de.
authors: Michael
authors: M
authors: Lämmerhofer
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid; D057930:Click Chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D012822:Silicon Dioxide / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D012997:Solvents; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D012833:Siloxanes; D012997:Solvents; D013438:Sulfhydryl Compounds; D012822:Silicon Dioxide
keywords: (29)Si cross-polarization magic angle spinning NMR spectroscopy; Chiral stationary phase; Coating; Crosslinked polysiloxane-coated silica particles; LC-MS; N-Derivatized amino acid; Thiol-ene click reaction