Chemical analysis of samples was performed by gas chromatography
(GC) with a flame ionization detector (FID) using
a Varian CP-3800 coupled with a Varian Saturn 2000MS
ion-trap mass spectrometer (MS), both controlled by Varian
MS Workstation 6.9 software. The GC-FID/MS instrument is
equipped with two split/splitless injectors and an automatic
sampler HT250D by HTA SrL.