Because much of the evidence that is left at a crime scene consists of organic compounds, infrared spectroscopy is useful in forensic investigations. … Infrared spectroscopy can be used to identify forged or altered documents by shining a beam of infrared light on the document’s ink.
What is infrared spectroscopy forensics?
Infrared (IR) spectroscopy is a technique based on the vibrations within a molecule. … The versatility of IR spectroscopy enables solids, liquids and gases to be sampled in a non-destructive manner. IR spectroscopy has been adopted as a tool for the forensic analysis of a range of evidence types.
What are the uses of IR spectroscopy?
Infrared (IR) spectroscopy is a vibrational spectroscopic technique based on the absorption of infrared radiation by matters that excite vibrations of molecular bonds. It is a powerful method for investigating structural, functional, and compositional changes in biomolecules, cells, and tissues.
Why would a forensic investigator use infrared spectroscopy on a fiber sample?
For example, if a fiber has been degraded by burial or by time, the surface features needed to identify it may no longer be present. In this case, infrared microspectroscopy could identify the fiber as proteinaceous, cellulosic, or synthetic.
How is infrared used to prevent crime?
Because infrared cameras have the capability to record in complete darkness, they are very useful for surveillance purposes. … This would allow them to record a crime in progress without the perpetrator ever knowing that the camera (or infrared light source) existed, even if it was completely dark at the time.
What are the limitations of IR spectroscopy?
Disadvantages of IR
Sample Constraint: Infrared spectroscopy is not applicable to the sample that contains water since this solvent strongly absorb IR light. Spectrum Complication: The IR spectrum is very complicated and the interpretation depends on lots of experience.
What is IR spectroscopy range?
The higher energy near-IR, approximately 14000-4000 cm-1 (0.8-2.5 μm wavelength) can excite overtone or harmonic vibrations. … The mid-infrared, approximately 4000-400 cm-1 (2.5-25 μm) may be used to study the fundamental vibrations and associated rotational-vibrational structure.
What are the two main applications of IR spectroscopy?
Infrared spectroscopy is widely used in industry as well as in research. It is a simple and reliable technique for measurement, quality control and dynamic measurement. It is also employed in forensic analysis in civil and criminal analysis.
What is the basic principle of IR spectroscopy?
IR spectroscopy detects the absorption of light by a compound, in the IR region of the electromagnetic spectrum. To absorb light a molecule must have a bond within its structure that can exhibit what is referred to as a ‘dipole moment’ which means electrons within a bond are not shared equally.
Why is FTIR used in forensic science?
FTIR is a valuable forensic technique because of its detection sensitivity and versatility. Chemicals from a variety of sample types including blood , paints, polymer coatings, drugs and both organic and inorganic contaminants can be identified.
What kind of thing is an infrared?
Infrared radiation (IR), or infrared light, is a type of radiant energy that’s invisible to human eyes but that we can feel as heat. All objects in the universe emit some level of IR radiation, but two of the most obvious sources are the sun and fire.
How is FTIR used in forensic science?
Fourier transform infrared spectroscopy (FT-IR) has proven to be a valuable tool for the forensic scientist on the macroscopic level. … The Nicolet iN10 provides the forensic scientist with an analytical tool to visually and chemically analyze illicit tablets, hair, fibers, inks, and paints.
Can police helicopters see into houses?
Police Helicopters can see into your home only when looking through a window with the HD color camera. The infrared camera is unable to look through walls, roofs, or structures because it only detects heat given off by an object.
Is thermal imaging legal?
The Court held that when the government uses a device, like the thermal imaging camera, that is not in general public use to explore details of a home that would previously have been unknowable without physical intrusion, the surveillance is a search and is presumptively unreasonable without a warrant.
How is infrared light used to identify fibers?
After analyzing the merits and demerits of the current methods used to identify fibers, near-infrared (NIR) spectroscopy was used owing to its significant superiorities, the foremost of which is it can capture the tiny information differences in chemical compositions and morphological features to display the …