2, 5-hexanedione

2,5-Hexanedione (2,5-HD), the main metabolite of n-hexane was extracted from urine samples using cold fiber head space solid-phase microextraction (CF-HS-SPME) based on thermoelectric cooling and analyzed with gas chromatography equipped with a flame ionization detector (GC-FID). Important parameters for improved efficiency of fiber sorption including sample volume, extraction time and temperature were optimized using a central composite design. The optimum conditions were determined, under which the detection limit and the relative standard deviations were found.