Jan 01, 2009 · A gas chromatograph with a mass selective detector GC/MS-QP2010 (Shimadzu, Columbia, MD, USA) coupled with a AOC-5000 autosampler (Shimadzu, Columbia, MD, USA) was used for analysis. All steps of the HS-SPME experiments including preheating of the sample, sample agitation, headspace adsorption, and desorption in the GC injection port were