Forensic Chemistry: Microcrystalline Drug Chemistry, Refractive Index Investigation, and Firearm Serial Number Restoration
Arts and Sciences
Valparaiso University recently approved a minor in forensic science. Development of a new laboratory-based course, CHEM 340: Forensic Chemistry, is one requirement for the minor. Described here are three experiments developed for CHEM 340, along with modified versions that can be used for the existing course NS 101: Introduction to Forensic Science. In one experiment, a solution containing gold chloride or mercurous chloride is combined with a suspected drug material. Many drugs, including cocaine and heroin, react with the reagents to form characteristic crystals that can be observed under a microscope. This micro-chemical technique can often quickly identify unknown drugs recovered from crime scenes. Caffeine serves as a surrogate drug to minimize safety and health concerns. In a second experiment, glass submitted from a crime scene as trace evidence is immersed in a series of oils with slightly different optical properties. Through the microscopic observation of Becke lines and the application of Snell’s Law, the refractive index of the glass can be determined and the type of glass can be identified or matched with other pieces of glass. In the final experiment, a series of acids are used to restore serial numbers that have been obliterated from metal parts of firearms.
White, Raechel M., "Forensic Chemistry: Microcrystalline Drug Chemistry, Refractive Index Investigation, and Firearm Serial Number Restoration" (2016). Symposium on Undergraduate Research and Creative Expression (SOURCE). 521.