Chromatogram of gasoline vapor sampled at ambient pressure and tem-perature using sorbent tubes containing ∼200 mg of Tenax TA. Gasoline vapor wasanalyzed by thermal desorption coupled to GC–FID using conventional columncontaining (5% phenyl-, 95% dimethyl-polysiloxane). Desorption temperature andtime were 300◦C and 25 min respectively. Toluene peak at ∼1.4 min (16 ppmv) andp-xylene (14 ppmv) peak at ∼2.4 min. Benzene and ethylbenzene not detected. Tem-perature programming: 35◦C, hold for 10 min, 5◦C/min to 150◦C, final hold time1 min.