| The purpose of this study is to determine whether similar looking undyed fibers can be differentiated by microspectrophotometry. Several classes of undyed fibers will be analyzed independently, and their UV transmittance properties will be examined.; Undyed fibers are very commonly encountered by forensic fiber examiners. Identification of the undyed fiber is fairly routine, but the question becomes how to differentiate between fibers within a class, such as polyester or cotton, for example. One possibility is that optical brighteners may play an important role in distinguishing fibers, similar to the way textile dyes are used to differentiate dyed fibers. Textile dyes can be differentiated through various analytical techniques, and a UV-visible microspectrophotometer is but one example. A microspectrophotometer allows the forensic scientist to measure the transmission, reflectance, or fluorescence characteristics of fibers.; Optical brighteners are often used on fibers during the manufacturing process or acquired through commercial detergents. Perhaps these optical brighteners will cause similar looking fibers, originating from different sources, to behave differently when exposed to electromagnetic radiation. |
