2.4 Analysis and quantification of volatile compounds by GC-MS
system
The analysis of emitted, free endogenous and bound endogenous volatile
compounds was conducted using ThermoScientific GC-MS system (GC-Trace
1300 equipped with ISQ QD, Single Quadrupole Mass Spectrometer); the GC
was equipped with a split mode injector and a TG-5MS capillary column
(length 30 m, 0.32 mm i.d., 0.25 µm film thickness). Analysis of
compounds was done as described earlier by Barman and Mitra (2019). The
identity of compounds was confirmed by calculating the retention indices
relative to C8-C20 n-alkanes.
Quantification of compounds was done by external standardization method
as described by Majetic and Sinka (2013), using ethyl hexanoate as a
known standard. Emitted and endogenous contents of individual scent
compound were calculated in nanomole
per gram fresh weight of sample
using this method: (Peak area of compound× moles of ethyl
hexanoate)/peak area of ethyl hexanoate.