Chemical composition of volatile oils from leaves and flowers of Sideritis congesta using direct thermal Desorption - Two-dimensional gas chromatography - Time-of-flight mass spectrometry

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Volatile oils from the leaves and flowers of Sideritis congesta, a plant endemic to Southern Anatolia, Turkey, were liberated using direct thermal desorption (DTD) and then analysed using comprehensive gas chromatography (GC x GC) coupled with time-of-flight mass spectrometry (TOF-MS). Two methods of thermal desorption are compared here; i) a manual direct cryo cooled on-column collection and focusing, and ii) a fully automated two stage carbon adsorbent thermal desorption system. 41 different volatile components were identified associated with plant leaves and 54 components for the flowers. A comparison of the flower volatiles resolved using the different thermal desorption methods indicated 43 common components, but with the cryo-cooled on-column method giving a slightly better determination. Major organic constituents observed from this species were alpha-pinene (12.53-14.55 %), beta-pinene (17.15-25.34 %) and delta-cadinene (10.97-14.52 %). Results for manual and automated DTD methods are similar: both of them allow a fast plant volatile analysis without the costly and time consuming step of extraction or distillation.

Original languageEnglish
Pages (from-to)22-29
Number of pages8
Issue number1
Publication statusPublished - Jan 2008


  • Sideritis congesta
  • volatiles
  • direct thermal desorption
  • comprehensive gas chromatography
  • time-of-flight mass spectrometry
  • L.

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