Compound identification was conducted using an Agilent 5975 C GC–MSD system. Helium carrier (99.999% purity) with flow rate of 1.0 mL/min initially, was increased immediately to 3.0 mL/min once the program started. The same column set and configuration was used for separation of volatiles, with the CT located 10 cm from the inlet end of the column, and the outlet was connected to the MSD through a transfer line heated at 280 ◦ C. Electron ionisation mode (70 eV; 230 ◦ C) and a mass scan range from 40 to 350 m/z were used. MS data processing utilized the automated mass spectral deconvo- lution and identification system (AMDIS) program version 2.66, and NIST MS matching library version 2.0f.