Presented by : Suliman Atallah University Of Huddersfield
Ministry Of Interior -Libya
Each point represents a peak in the chromatograph normalised with respect to the largest peak and showing how the ratio in peak sizes varies between the liquid and the vapour.
No petrol residues were found on any of the pieces of burnt clothes.
- The studies on fire debris utilised petrol and white spirit which were placed on clothes samples (7.5cm x 9.5cm) and burnt under fixed conditions.
- Residues were collected in nylon bags for analysis.
- Sample analysis was carried out using 1 μl injections, a temperature program of 40°C/min from 50 °C to 230 °C with an initial 2 minute hold.
- The helium gas flow rate was 25ml/min (split1:20) and a detector temperature of 330 °C.
Arson is the main cause of fire, which costs the UK an estimated £2 billion a year. The majority of arson attacks in the UK are on residential properties. Each year there are about 87,095 attacks on homes, which kill 65 people and injure 2010. (1)
Forensic fire investigation involves the detection of accelerant residue in fire debris that has been collected from a fire scene.(2)
This study will focus on the effectiveness of manual and automated HS-GC in detecting fuel in accelerants
Discussion and Conclusion
- The chromatograph of the liquid and the headspace of a pure accelerant were very different. The less volatile components were not detected using headspace.
- Manual / automated headspace injection gave a better resolution result with the BPX-5 column rather than the BP-20 column.
- Reliable analysis of arson accelerants is limited with GC-FID, as peaks cannot be identified. GC-MS would be a better instrument where each component in the mixture can be identified.
Equipment and materials:
- Varian 3900 gas chromatography and Auto-headspace Agilent 7697, in conjunction with 8690 Gas chromatography, were fitted with a flame ionization detector and capillary column.
- Two columns were used and compared: BP20 (polar) and BPX-5 (non-polar). Both columns were 25 m in length with a 320 um bore.
- The accelerants studied included petrol, white spirit, aviation fuel, kerosene, diesel and pure turpentine.
- Recent advances in the applications of forensic science to fire debris analysis, J. Dolan , 2003, published by Springer-Verlag USA.