title: Potential and limitations of on-line comprehensive reversed phase liquid chromatography×supercritical fluid chromatography for the separation of neutral compounds: An approach to separate an aqueous extract of bio-oil.
abstract: On-line comprehensive Reversed Phase Liquid Chromatography×Supercritical Fluid Chromatography (RPLCxSFC) was investigated for the separation of complex samples of neutral compounds. The presented approach aimed at overcoming the constraints involved by such a coupling. The search for suitable conditions (stationary phases, injection solvent, injection volume, design of interface) are discussed with a view of ensuring a good transfer of the compounds between both dimensions, thereby allowing high effective peak capacity in the second dimension. Instrumental aspects that are of prime importance in on-line 2D separations, were also tackled (dwell volume, extra column volume and detection). After extensive preliminary studies, an on-line RPLCxSFC separation of a bio-oil aqueous extract was carried out and compared to an on-line RPLCxRPLC separation of the same sample in terms of orthogonality, peak capacity and sensitivity. Both separations were achieved in 100min. For this sample and in these optimized conditions, it is shown that RPLCxSFC (with Hypercarb and Acquity BEH-2EP as stationary phases in first and second dimension respectively) can generate a slightly higher peak capacity than RPLCxRPLC (with Hypercarb and Acquity CSH phenyl-hexyl as stationary phases in first and second dimension respectively) (620 vs 560). Such a result is essentially due to the high degree of orthogonality between RPLC and SFC which may balance for lesser peak efficiency obtained with SFC as second dimension. Finally, even though current limitations in SFC instrumentation (i.e. large extra-column volume, large dwell volume, no ultra-high pressure) can be critical at the moment for on-line 2D-separations, RPLCxSFC appears to be a promising alternative to RPLCxRPLC for the separation of complex samples of neutral compounds.
authors.affiliation: Université de Lyon, Institut des Sciences Analytiques, UMR CNRS UCBL ENS 5280, 5 rue de la Doua, 69100 Villeurbanne, France.
authors.forename: Morgan
authors.initials: M
authors.lastname: Sarrut
authors.affiliation: Université de Lyon, Institut des Sciences Analytiques, UMR CNRS UCBL ENS 5280, 5 rue de la Doua, 69100 Villeurbanne, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Corgier
authors.affiliation: Université de Lyon, Institut des Sciences Analytiques, UMR CNRS UCBL ENS 5280, 5 rue de la Doua, 69100 Villeurbanne, France.
authors.forename: Gérard
authors.initials: G
authors.lastname: Crétier
authors.affiliation: IFP Energies nouvelles, Rond-Point de l'échangeur de Solaize, BP3, 69360 Solaize, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Le Masle
authors.affiliation: Waters SAS, BP608, 78056 St Quentin en Yvelines, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Dubant
authors.affiliation: Université de Lyon, Institut des Sciences Analytiques, UMR CNRS UCBL ENS 5280, 5 rue de la Doua, 69100 Villeurbanne, France. Electronic address: sabine.heinisch@univ-lyon1.fr.
authors.forename: Sabine
authors.initials: S
authors.lastname: Heinisch
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods* / Q000592:standards; D056148:Chromatography, Reverse-Phase; D025924:Chromatography, Supercritical Fluid; D006863:Hydrogen-Ion Concentration; D009821:Oils / Q000737:chemistry / Q000302:isolation & purification*; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D009821:Oils; D012997:Solvents; D014867:Water
keywords: Bio-oils; Biomass; Complex samples; Comprehensive two-dimensional chromatography; On-line RPLCxSFC; Supercritical fluid chromatography (SFC)