What type of analysis is used to identify substances found at crime scenes?

Spectroscopy is a powerful analytical technique used to identify substances by measuring the interaction of light with matter. When analyzing samples collected from a crime scene, spectroscopy can provide detailed information about the chemical composition by examining how substances absorb, emit, or scatter light. This technique is particularly effective for identifying various compounds based on their unique spectral signatures.

In forensic science, different forms of spectroscopy, such as infrared (IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy, are commonly employed due to their ability to non-destructively analyze complex mixtures and provide qualitative and quantitative data regarding the presence of specific chemicals.

While chromatography, mass spectrometry, and thermal analysis are also significant analytical techniques used in forensic science, they serve different primary purposes. Chromatography is mainly used for separating mixtures into their individual components, mass spectrometry is typically employed for determining molecular weights and structures of compounds, and thermal analysis involves studying the physical and chemical properties of materials as they change with temperature. Each technique has its specific applications, but spectroscopy stands out for its direct use in identifying substances at crime scenes.