SPME-GC-FID analysis of headspace of Petri-plate
SPME-GC-FID analysis was done as described earlier (Pragadheesh et al., 2013). The SPME fiber (DVB/CAR/PDMS) was exposed to heated injector for 1 h at 270 °C prior to adsorption. The activated fiber was then exposed to headspace of Petri-plate containing essential oil for 15 min followed by desorption to heated injector. The validation of SPME fiber was carried out with respect to the camphor concentration and time of exposure. The linearity (R2) of the FID for camphor was calculated using a multiple point external standard method and recorded as 0.997.