Question

What are some instruments/techniques that are important for research in forensic science? Explain the theories in lay terms.

Answer 1

Forensic chemical instruments/techniques:

1. It comprises of organic and inorganic analysis, toxicology, arson investigation and serology.

2. It includes ultraviolent, infrared and visible spectrophotometry, neutron activation analysis, gas chromatography and mass spectroscopy , high pressure liquid chromatography and atomic absorption spectrophotometry. The techniqu and instrumentation chosen depend on the type of sample or substance to be examined.

3. Arsonists often use accelerants such as gasoline or kerosene to speed combustion and spread flames in the interior of a building. Samples of burned and unburned materials , extract the volatile hydrocarbon and separate the components for analysis by gas chromatography.

4. UV spectroscopy helps to distinguish between samples of protein and nucleic acid.

5.mass spectroscopy breaks sample apart and separates the ionised fragments by mass and charge which helps in indentification even if the sample is very small.

6. IR spectroscopy is especially useful for the indentification of organic compound as bonds between certain atoms readily absorbs infrared radiation.

7. Absorption spectroscopy provides ways for determining absorption and emission spectra useful tools in the analysis of metals such as bullet fragments.

8. NMR makes use of the fact that nuclei of some molecules absorb radio frequency radiation in strong magnetic fields. Nuclei in certain molecules absotb raduation at characteristics frequencies making the identification of even tiny or impure samples possible. X rays analysis allows the forensic investigator to visualize foreign objects within the body.

9. In neutron activation analysis a beam of neutron from a nuclear reactor is directed at a sample of test material. The material becomes temporaryly radioactive emitting gamma ray that are characteristics of composition which is highly accurate.