Analysis of Dyed Textile Fibers: Connecting Small Molecule and Polymer Chemistry with Forensic Science

An upper division laboratory experiment focuses on the characterization of the chemical structures of fiber samples using a solubility test and FTIR (Fourier transform infrared) spectroscopy, and solvent extraction followed by TLC (thin layer chromatography) and UV-vis spectrometry for the detection of the dye component found in the fiber. Laboratory reports and embedded questions are used to assess the accomplishment of the learning outcomes. This activity provides students with additional opportunities (beyond those presented in introductory classes) to work with widely applicable techniques and simultaneously links polymer, organic, and general chemistry concepts with forensic applications. The protocol can also be easily adapted to address a variety of learning objectives.