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Application of comprehensive multidimensional gas chromatography combined with time‐of‐flight mass spectrometry (GC×GC‐TOFMS) for high resolution analysis of hop essential oil
Author(s) -
Roberts Mark T.,
Dufour JeanPierre,
Lewis Alastair C.
Publication year - 2004
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200301669
Subject(s) - gas chromatography , chemistry , mass spectrometry , two dimensional gas , chromatography , time of flight mass spectrometry , hop (telecommunications) , kovats retention index , elution , two dimensional chromatography , resolution (logic) , analytical chemistry (journal) , mass spectrum , electron ionization , gas chromatography–mass spectrometry , flame ionization detector , homologous series , ionization , artificial intelligence , computer science , ion , computer network , organic chemistry
The selection and quality of hops is a major determinant in beer flavour. Brewers acknowledge that distinctive characteristics of different hop varieties can be traced to the composition of their essential oils. The difficulty in characterising complex mixtures such as hop oil using 1‐D chromatography is that many compounds co‐elute. With the introduction of comprehensive multidimensional capillary gas chromatography (GC×GC), there is a tremendous improvement in the separation power or peak capacity. Recent work using GC×GC with flame ionisation detection has suggested that there may be over 1,000 compounds in hop oil. This work describes the use of GC×GC combined with TOFMS detection (Leco Pegasus 4D instrument) to analyse Target hop oil. The TOFMS spectral acquisition rate of 60 Hz provided sufficient spectra per peak (2‐D peak base width of 0.1–0.2 s) for identification (119 components were identified with 45 previously unreported compounds). When analysing results, an advantage of GC×GC coupled to TOFMS is that 2‐D chromatograms can be viewed for individual masses that are characteristic of particular functional groups. This allows the analyst to view the various homologous series of compounds although in certain cases coelution may still be present as shown by the esters with mass 75.