title: Parallel dual secondary column-dual detection: a further way of enhancing the informative potential of two-dimensional comprehensive gas chromatography.
abstract: Comprehensive two-dimensional gas chromatography (GC×GC) coupled with Mass Spectrometry (MS) is one of today's most powerful analytical platforms for detailed analysis of medium-to-high complexity samples. The column set usually consists of a long, conventional-inner-diameter first dimension ((1)D) (typically 15-30m long, 0.32-0.25mm dc), and a short, narrow-bore second dimension ((2)D) column (typically 0.5-2m, 0.1mm dc) where separation is run in a few seconds. However, when thermal modulation is used, since the columns of a set are coupled in series, a flow mismatch occurs between the two dimensions, making it impossible to operate simultaneously at optimized flow conditions. Further, short narrow-bore capillaries can easily be overloaded, because of their lower loadability, limiting the effectiveness of (2)D separation. In this study, improved gas linear velocities in both chromatographic dimensions were achieved by coupling the (1)D column with two parallel (2)D columns, having identical inner diameter, stationary phase chemistry, and film thickness. In turn, these were connected to two detectors: a fast quadrupole Mass Spectrometer (MS) and a Flame Ionization Detector (FID). Different configurations were tested and performances compared to a conventional set-up; experimental results on two model mixtures (n-alkanes and fourteen medium-to-high polarity volatiles of interest in the flavor and fragrance field) and on the essential oil of Artemisia umbelliformis Lam., show the system provides consistent results, in terms of analyte identification (reliability of spectra and MS matching) and quantitation, also affording an internal cross-validation of quantitation accuracy.
authors.affiliation: Faculty of Chemistry, Technical University of Munich, Lise-Meitner-Strasse 34, 85354 Freising, Germany.
authors.forename: Luca
authors.initials: L
authors.lastname: Nicolotti
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, I-10125 Turin, Italy. Electronic address: chiara.cordero@unito.it.
authors.forename: Chiara
authors.initials: C
authors.lastname: Cordero
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, I-10125 Turin, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Bressanello
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, I-10125 Turin, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Cagliero
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, I-10125 Turin, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Liberto
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, I-10125 Turin, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Magagna
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, I-10125 Turin, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Rubiolo
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, I-10125 Turin, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sgorbini
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, I-10125 Turin, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Bicchi
mesh_terms: D000473:Alkanes / Q000032:analysis; D005410:Flame Ionization; D005421:Flavoring Agents / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation* / Q000379:methods; D009822:Oils, Volatile / Q000737:chemistry; D010476:Perfume / Q000032:analysis; D015203:Reproducibility of Results
chemical_list: D000473:Alkanes; D005421:Flavoring Agents; D009822:Oils, Volatile; D010476:Perfume
keywords: Dual (2)D pattern alignment; Essential oil analysis; Outlet pressure correction; Parallel dual secondary column-dual detection; Second dimension linear velocity optimization; Two-dimensional comprehensive gas chromatography-mass spectrometry