“…Solid phase microextraction fibers were individually placed in a single SPME fiber holder for manual injection (Supelco, Bellefonte, PA, U.S.A.) and preconditioned in the injector port of the GC at 300 C for 30 min. Prior to sampling, a rubber foam septum was placed on the package film to prevent leakage of headspace or equilibration with the outside environment (Rotabakk, Wyller, Lekang, & Sivertsvik, 2008;Sharma et al 2011). The SPME sheath containing the needle was then inserted through the septum; the SPME needle was exposed to the headspace of the package for a 40 min sampling time at a sampling temperature of 22 C. At the end of the sampling time, the fiber was removed and immediately placed into the injector port of the GC for a desorption period of 3 min at a temperature of 250 C. Each package was discarded following headspace sampling.…”