Trace level determination of enantiomeric monoterpenes in terrestrial plant emission and in the atmosphere using a β-cyclodextrin capillary column coupled with thermal desorption and mass spectrometry

For the first time, enrichment on solid sorbents followed by thermal desorption has been used for the determination of the enantiomeric signature of monoterpenes in the gaseous emission of terrestrial plants. A β-cyclodextrin capillary column has been used for the separation of critical pairs. The temperature program and column loading were optimized for making the accurate quantification of individual enantiomers possible by mass spectrometry. The resolution achieved was sufficient for separating enantiomeric monoterpenes from other biogenic and anthropogenic volatile organic compounds present in air and vegetation emission samples. The method has been applied to the determination of the enantiomeric ratios of monoterpenes in the gaseous emissions of some evergreen plants and in the open atmosphere.