Relative amounts and enantiomeric compositions of monoterpene hydrocarbons in xylem and needles of Picea abies

Abstract

The relative amounts of 23 monoterpene hydrocarbons, including enantiomers, present in extracts of branch xylem and needles from 41 Picea abies plus-trees of widely different origins, were determined. A two-dimensional gas chromatographic system was used for the determination of the enantiomeric compositions of the seven major chiral monoterpenes. Data were evaluated by multivariate data analysis. Large variations were found in the enantiomeric compositions, as well as in the relative amounts of the monoterpenes, both within and among the trees. Trees from the same geographic area did not show a greater similarity in their composition of volatiles than trees from different geographic areas. In the xylem, (−)-β-pinene and (−)-β-phellandrene, and in the needle samples, (−)-α-pinene, (−)-limonene and (−)-camphene, dominated over their (+)-enantiomers. Among-tree variation in enantiomeric composition was higher in xylem samples than in needle samples, except for β-pinene and β-phellandrene.