title: Evaluation of reversed phase columns designed for polar compounds and porous graphitic carbon in "trapping" and separating neurotransmitters.
abstract: Quantification of neurotransmitters as biologically active analytes in neurological samples is of high interest for studying their effect on multiple targets. This work is part of a strategy involving two-dimensional liquid chromatography (2D LC) system with mass spectrometry (MS) detection. The concept of the on-line LC system is the coupling of reversed phase liquid chromatography (RPLC, the second separation dimension) to ion-exchange chromatography (IEC, the first dimension). Our objective in this study is to find the appropriate second dimension column, ensuring that samples of neurotransmitters are refocused and separated on it. Silica-based columns designed specifically to retain polar compounds were tested in LC conditions and compared with results obtained with a porous graphitic carbon (PGC, Hypercarb) column. These polar embedded, polar endcapped, and high-density alkyl chain columns successfully separated analytes in question using mobile phase systems with high percentage of water, or even pure water. Only Hypercarb column provided efficient retention of the most polar neurotransmitters and could be used for trapping and preconcentrating the compounds without rapid breakthrough.
authors.affiliation: Laboratoire Environnement et Chimie Analytique (CNRS, UMR 7121), ESPCI, 10 rue Vauquelin, 75005 Paris, France. didier.thiebaut@espci.fr
authors.forename: Didier
authors.initials: D
authors.lastname: Thiébaut
authors.forename: Jérôme
authors.initials: J
authors.lastname: Vial
authors.forename: Monika
authors.initials: M
authors.lastname: Michel
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Hennion
authors.forename: Tyge
authors.initials: T
authors.lastname: Greibrokk
mesh_terms: D002852:Chromatography, Ion Exchange / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D018377:Neurotransmitter Agents / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D018377:Neurotransmitter Agents; D012822:Silicon Dioxide; D006108:Graphite