shows greater sensitivity in detecting gasoline in a study at levels where other passive methods have failed [29] and is unaffected by interferences from the pyrolysis products of wood and plastics [35]. In addition headspace sampling eliminates interfer- ences, can be used when aqueous media are present and has the ability to be used in the field. Therefore in fire investigation, HS-SPME is poten- tially useful due to complex matrix composition and potentially high water content. DI-SPME has been applied to the recovery of accelerants and explosives from aqueous samples [36,37], but a SPME method has not been reported so far. Water samples represent 5% of all samples for fire investigation [9] and liquid matrix membrane SPME has been applied to complex and dirty matrices [38]. Direct-contact SPME has been applied to soil by Yoshida et al. [39], with the technique also used for identification of ignitable liquids from human skin [27]. The SPME method, compared with traditional LLE, limits loss of petroleum products during the sampling procedure since the process incorporates extraction, concentration and injection into a single step, which, in turn, makes it more time efficient. Additionally, the HS mode provides a lon- ger lifetime of the fiber and protects the fiber from any adverse effects that may occur due to non-volatile, high molecular weight substances in the real samples. This allows determination of petroleum products in low levels of concentrations with greater accuracy and precision.