NCJ Number
136032
Journal
Journal of Forensic Sciences Volume: 37 Issue: 2 Dated: (March 1992) Pages: 620-631
Date Published
1992
Length
12 pages
Annotation
This article describes the procedures and benefits of obtaining infrared spectra from single microfibers with a specifically designed anvil and template to preflatten the fiber perpendicular to the infrared (IR) path.
Abstract
The anvil and template described have been designed to allow up to 10 fiber mounts which are flattened perpendicular to the IR beam. The combination of the flattened profile and consistent orientation of the fiber to the IR beam minimizes diffraction and crystal alignment effects. The device also facilitates easy recovery of the fibers for further comparison. The template was designed to fit the stage of a Spectra-Tech Model 0036-033 microscope attached to a Perkin-Elmer Series 1750 Fourier transform infrared spectrometer equipped with a Judson MCT detector. The device consists of a plate 76 mm long, 16 mm wide, and 3 mm thick. A slot 3 mm wide and 25 mm long was cut into the center of the plate from one end. A mating anvil was machined into a base plate to match the slot in the plate. A small chamfer was machined into the leading edge of the slot to guide a scalpel tip when incising the tape placed across the plate and anvil. This article describes the analysis procedure step by step. In addition to the rapid preparation of up to 10 fiber mounts and the ease of recovery for further tests, the procedure facilitates maintenance of the security of the fiber, presentation of a flattened fiber in a consistent orientation to the IR beam, and a reduction in diffraction effects and improved optical transparency. 11 figures and 12 references