In forensic fire debris analysis, extracted samples must be compared to an extensive reference collection that must include liquids evaporated to various levels. The evaporation of these ignitable liquids is currently done in-house, in a process that may be time-consuming and with methods that vary from laboratory to laboratory. As such, our laboratory previously developed a kinetic model to predict chromatograms of evaporated ignitable liquids to which samples may be compared. However, development and validation of this model were accomplished under different evaporation conditions and without the use of passive headspace extraction. Therefore, the objectives in this work were to evaluate the effect of evaporation mode and extraction on the predictive success of the kinetic model. To do this, gasoline samples were evaporated to varying evaporation levels under three evaporation modes: 1) in a graduated cylinder with sparging and agitation, 2) without agitation, and 3) in a petri dish with no sparging or agitation to simulate a thin film. Samples were then analyzed with gas chromatography – mass spectrometry (GC-MS). Additionally, gasoline and paint thinner were evaporated in a graduated cylinder with sparging and agitation, then analyzed both with and without passive-headspace extraction. Chromatograms of the experimentally evaporated ignitable liquids were compared to chromatograms predicted by the kinetic model using Pearson product-moment correlation (PPMC) coefficients and mean absolute percent error (MAPE). Overall, the model performed well, with strong correlation between experimental and predicted chromatograms regardless of evaporation mode and the presence of extraction.
(Publisher abstract provided.)
Downloads
Similar Publications
- Data fusion from infrared, elemental, MSP and Raman for maximizing the efficiency of the forensic examination of paint evidence
- A collaborative exercise on DNA methylation-based age prediction and body fluid typing
- Review of Several False Positive Error Rate Estimates for Latent Fingerprint Examination Proposed Based on the 2014 Miami Dade Police Department Study