Clean recovery and HRGC-MS/HRGC-FTIR identification of volatiles from soybean (Glycine max)

Volatiles from soybean leaves (Glycine max., var. Canton) were investigated to gain knowledge about these compounds for developing new methods to control phytophagous insects in soybean fields. To extract the volatiles, two methods based on analysis of the dynamic headspace were used: thermal desorption cold trap injector (TCTI) and purge and trap injector (PTI). The separation of the compounds was carried out by gas chromatography with mass spectroscopy (HRGC-MS) and Fourier-transform infrared spectroscopy (HRGC-FTIR). The most abundant compounds were represented by: (Z)-3-hexenyl-acetate, 1-hexanol, (Z)-3-hexen-1-ol and 1-octen-3-ol. The addition of an internal standard to the samples allowed semiquantitative data to be accumulated. Solid phase microextraction (SPME) was used to characterize the profile of the volatiles from homogenized soybean leaves. There were substantial differences in comparison to the profile obtained from intact leaves; this should be due to the chemical and enzymatic modifications occurring during homogenization.