About
2 lL of the sample was injected for the analysis. Helium was used as the carrier gas and supplied at the flow rate of 1 mL/min, with a
split ratio of 1:10. The oven temperature was increased from 60 C
to 150 C at the ramp rate of 6 C/min and held at 150 C for 2 min.
This was followed by temperature increase to 280 C at the rate of
4 C/min and held at the same temperature (280 C) for 5 min. The
injector was maintained at 280 C. The mass spectra were recorded
at 70 eV over a mass-to-charge ratio range of 40–450 amu. The
chemical compositions were identified by direct comparison of
their mass spectral pattern in NIST 2005 mass spectral library.