Resumen de Who Set the Fire? Determination of Arson Accelerants by GC-MS in an Instrumental Methods Course
David A. Sodeman, Sheri J. Lillard
Forensic scenarios have advantages over traditional experiments in the instrumental laboratory from the perspectives of both teaching and learning. First, students feel that they are calculating more than just a number from their experiments and that their results have meaning. Second, we are teaching techniques that are used in the real world and students can no longer complain, "This is not how it is done in the real world." This experiment is designed for upper-division chemistry and chemical engineering majors taking an instrumental methods course. The experimental approach simulates the steps an arson investigator would take to determine if arson was the cause of a fire. Charred (unknown) samples of wood and five standards of liquid accelerants are prepared in sealed containers and presented to the students for headspace gas chromatography (GC) with quadrupole mass spectrometric (MS) detection. Students interpret the standards and the charred samples using chromatographic retention times and MS data. From this information, they determine which accelerant was used to start the fire. They are also asked to discuss differences between the chromatograms of the charred sample and the corresponding liquid accelerant.
