02197nam a2200265 4500 392325 392325 20140120d2012 y0pory50 ba eng Evaluation of cross-contamination of nylon bags with heavy loaded petrol fire debris Filipa Belchior Lancashire [s.n.] 2012 xiii, 116, [38] p. anexos 30 cm Submitted (September 2012) in partial fulfilment of the requirement for the degree of Masters of Science in Fire Investigation - School of Forensic and Investigative Sciences - University of Central Lancashire (UCLan). The integrity of evidence is extremely important in forensic science and in the judicial system to avoid miscarriages of justice. Contamination and cross-contamination must be prevented. Evidence should be packed in a container that prevents loss or addition to the material. Nylon bags are the most used container for fire debris evidence in the UK and are also used in several European countries. Cross-contamination of nylon bags in normal casework conditions was studied, using heavy loaded petrol fire debris and using automotive topcoat thinner (oxygenated solvent). Samples were sealed with swan-neck with plastic cable ties in both ends and were stored in crates, typically used in the UK to transport evidence from the fire scene to the laboratories. The analyses were performed using gas chromatography / mass spectrometry. Cross-contamination was found for petrol in the two brands of nylon bags used, after significantly different periods of time. In both brands the same aromatic compounds were identified. Cross-contamination was also found using automotive topcoat thinner and using only one brand of bags. Oxygenated compounds and one aromatic compound were identified. CIÊNCIA FORENSE 321508 INCÊNDIO 243828 RECOLHA DA PROVA 322094 ANÁLISE DE VESTÍGIOS 320649 PRESERVAÇÃO DA PROVA 302776 TESE 334284 BELCHIOR Filipa 353764 Oferta 0 PJ_22_000000000000000_E_30 2022-06-06 PJ34158 424568 PJ PJ PJ134158 PJ22.E.30 2022-06-06 0 MO Oferta 0 PJCD_241_000000000000000 2022-06-06 PJCD241 424569 PJ PJ PJ1CD241_47 PJCD241 2022-06-06 0 MO Oferta 21,7 MB