title: A novel four-dimensional analytical approach for analysis of complex samples.
abstract: A two-dimensional LC (2D-LC) method, based on the work of Erni and Frei in 1978, was developed and coupled to an ion mobility-high-resolution mass spectrometer (IM-MS), which enabled the separation of complex samples in four dimensions (2D-LC, ion mobility spectrometry (IMS), and mass spectrometry (MS)). This approach works as a continuous multiheart-cutting LC system, using a long modulation time of 4 min, which allows the complete transfer of most of the first - dimension peaks to the second - dimension column without fractionation, in comparison to comprehensive two-dimensional liquid chromatography. Hence, each compound delivers only one peak in the second dimension, which simplifies the data handling even when ion mobility spectrometry as a third and mass spectrometry as a fourth dimension are introduced. The analysis of a plant extract from Ginkgo biloba shows the separation power of this four-dimensional separation method with a calculated total peak capacity of more than 8700. Furthermore, the advantage of ion mobility for characterizing unknown compounds by their collision cross section (CCS) and accurate mass in a non-target approach is shown for different matrices like plant extracts and coffee. Graphical abstract Principle of the four-dimensional separation.
authors.affiliation: Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Stephan
authors.affiliation: Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Jakob
authors.affiliation: Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Hippler
authors.affiliation: Applied Analytical Chemistry, University of Duisburg-Essen, Universitaetsstr. 5, 45141, Essen, Germany. oliver.schmitz@uni-due.de.
authors.forename: Oliver J
authors.initials: OJ
authors.lastname: Schmitz
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D045424:Complex Mixtures / Q000032:analysis*; D020441:Ginkgo biloba / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D045424:Complex Mixtures
keywords: 2D-LC; CCS; Ginkgo biloba; IM-qTOF-MS; Ion mobility; LC+LC