Infra Red Spectroscopy Essay

1288 Words3 Pages

Introduction:
Throughout centuries; researchers, scientists and engineers have brought about great innovations to the world. These innovations are limited to no single field, but instead have been shared throughout them all. Whether it is advanced weaponry and guidance systems or the remote that controls your television, advances have been made. One of the most notable advances has been in the field of criminology. Two new pieces of technology that have made quite a large impact are Infra-red Spectroscopy and Chromatography.
A body was found with no identification was found on the body. An external examination of the body found numerous needle marks and bruising and thrombosed veins in the cubital fossae. The head showed evidence of a blunt trauma and small paint and metal fragments were removed from the wound. Analysis of the contents in the stomach found a few partially digested potato chips and some partially digested pills. A small amount of residue was extracted from the tin for analysis. Footprints were evident on the carpet where soil had been tracked in. Soil samples were collected from theses footprints. This analysis will show how Infra-red spectroscopy and Chromatography would be useful in finding both the cause of murder and possibly who the culprit was.
Infra-red Spectroscopy:
Infra-red spectroscopy was first used in 1950's by Wilbur Kaye. He designed a machine that tested the near-infrared spectrum and was able to provide the theory to describe the results. There have been many advances in the field of IR Spec, the most applicable was the application of Fourier Transformations. ”The Fourier Transform is a tool that breaks a waveform (a function or signal) into an alternate representation, characterized by sine an...

... middle of paper ...

...the mass spectrometer. This is called an electron impact source. Gases and volatile liquid samples are allowed to leak into the ion source from a reservoir. Non-volatile solids and liquids may be introduced directly. Cations formed by the electron bombardment (red dots) are pushed away by a charged repeller plate (anions are attracted to it), and accelerated toward other electrodes, having slits through which the ions pass as a beam. Some of these ions fragment into smaller cations and neutral fragments. A perpendicular magnetic field deflects the ion beam in an arc whose radius is inversely proportional to the mass of each ion. Lighter ions are deflected more than heavier ions. By varying the strength of the magnetic field, ions of different mass can be focused progressively on a detector fixed at the end of a curved tube. Because the mass of each individual ion

Open Document