Immediately after the second collection of volatiles, the
youngest fully developed leaflet of the same plant individuals
as used in VOC collections were extracted with 3ml of
n-hexane for 2 h at room temperature. After the filtration of
the extract, the plant residues were washed twice with 1ml
of pure hexane. Plant extracts were analyzed with GC-MS
(Hewlett Packard GC type 5890, MSD 5970) with a 30m
long HP-5MS (0.25mm i.d., 0.25m film thickness) capillary
column using helium as the carrier gas