Skip to Content
Merck
  • Parallel dual secondary column-dual detection: a further way of enhancing the informative potential of two-dimensional comprehensive gas chromatography.

Parallel dual secondary column-dual detection: a further way of enhancing the informative potential of two-dimensional comprehensive gas chromatography.

Journal of chromatography. A (2014-08-19)
Luca Nicolotti, Chiara Cordero, Davide Bressanello, Cecilia Cagliero, Erica Liberto, Federico Magagna, Patrizia Rubiolo, Barbara Sgorbini, Carlo Bicchi
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.

MATERIALS
Product Number
Brand
Product Description

Supelco
Vanillin melting point standard, Pharmaceutical Secondary Standard; Certified Reference Material
Coumarin, primary reference standard
Supelco
Mettler-Toledo Calibration substance ME 51143093, Vanillin, traceable to primary standards (LGC)
Sigma-Aldrich
Benzaldehyde, SAJ special grade, ≥98.0%
USP
Vanillin Melting Point Standard, United States Pharmacopeia (USP) Reference Standard
Supelco
Isoeugenol, analytical standard
Supelco
Sclareol, analytical standard
Supelco
Coumarin, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland
Benzaldehyde, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
(±)-Camphor, meets analytical specification of Ph. Eur., BP, racemic, ≥95% (GC)
Sigma-Aldrich
Vanillin, tested according to Ph. Eur.
Supelco
Benzaldehyde, analytical standard
Sigma-Aldrich
(±)-Camphor, purum, synthetic, ≥95.0% (GC)
Sigma-Aldrich
Benzaldehyde, puriss. p.a., ≥99.0% (GC)
Supelco
(−)-Camphor, analytical standard
Sigma-Aldrich
Sclareol, 98%
Sigma-Aldrich
Vanillin, natural, ≥97%, FCC, FG
Sigma-Aldrich
Vanillin, ≥97%, FCC, FG
Sigma-Aldrich
Camphor, 96%
Sigma-Aldrich
Vanillin, ReagentPlus®, 99%
Sigma-Aldrich
Benzaldehyde, ReagentPlus®, ≥99%
Sigma-Aldrich
Benzaldehyde, purified by redistillation, ≥99.5%
Sigma-Aldrich
(±)-Camphor, ≥95.5%
Sigma-Aldrich
Benzaldehyde, ≥98%, FG, FCC
Sigma-Aldrich
Isoeugenol, mixture of cis and trans, 99%, FG
Sigma-Aldrich
Isoeugenol, 98%, mixture of cis and trans
Sigma-Aldrich
Benzaldehyde, natural, FCC, FG
Sigma-Aldrich
Coumarin, ≥99% (HPLC)
Supelco
Benzaldehyde, Pharmaceutical Secondary Standard; Certified Reference Material
USP
Camphor, United States Pharmacopeia (USP) Reference Standard