What Is a Use of UV-Vis Spectroscopy in the Forensic

Question

Examlex · Accepted Answer

The Answer is UV-Vis spectroscopy, short for ultraviolet-visible spectroscopy, is a technique that measures the absorption of ultraviolet or visible light by a substance. In the forensic setting, UV-Vis spectroscopy serves several important purposes:

1. **Identification of Substances**: Forensic scientists can use UV-Vis spectroscopy to help identify unknown substances found at a crime scene. By comparing the absorption spectrum of the unknown substance to known spectra, they can often determine the substance's identity. This is particularly useful for identifying drugs, dyes, and inks.

2. **Analysis of Drugs and Poisons**: UV-Vis spectroscopy can be used to detect and quantify the presence of illicit drugs or poisons in biological samples such as blood, urine, or tissue. This is crucial in cases of drug overdoses, poisoning investigations, or in determining the influence of substances in crimes such as DUI (driving under the influence).

3. **Examination of Questioned Documents**: In cases involving questioned documents, such as forged documents or altered wills, UV-Vis spectroscopy can be used to analyze the inks used. Since different inks can have distinct absorption spectra, this technique can help determine whether multiple inks were used on a document, which might indicate tampering or forgery.

4. **Fiber Analysis**: Fibers collected from a crime scene can be analyzed using UV-Vis spectroscopy to determine their dye composition. This information can be used to link a suspect to a crime scene if the fibers from the scene match those from the suspect's clothing or belongings.

5. **Trace Evidence Analysis**: Small quantities of evidence, such as glass fragments or paint chips, can be analyzed using UV-Vis spectroscopy. The absorption spectra can provide information about the chemical composition and possibly the origin of these materials, which can be critical in hit-and-run accidents or burglaries.

6. **Detection of Latent Fingerprints**: Certain chemicals used to develop latent fingerprints on surfaces can be made visible under UV light. UV-Vis spectroscopy can be used to enhance the contrast between the fingerprint residue and the substrate, making the prints more visible for analysis.

7. **Age Estimation of Bruises**: In cases of assault or abuse, UV-Vis spectroscopy can sometimes be used to estimate the age of bruises on a victim. The technique can detect changes in the coloration of a bruise over time, which can be correlated with the time since the injury occurred.

Overall, UV-Vis spectroscopy is a versatile tool in forensic science, providing non-destructive and rapid analysis of a wide range of materials. Its ability to help identify and quantify substances makes it invaluable in the pursuit of justice.

What Is a Use of UV-Vis Spectroscopy in the Forensic

Definitions: