GC/MS measurement were made using a Finnigan Trace gas chromatograph interfaced to a Finnigan Trace DSQ quadrupole mass spectrometer (Thermo Electron Corpo-ration, USA), with an Thermo Xcalibur data system and the NIST 2005 spectra library. A fused silica capillary column (DB-1ms), 60 m long, 0.25 mm I.D. and 0.25 mm film thickness, was used.