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What kinds of samples can be examined with infrared spectroscopy?

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Learn about the use of gamma-ray spectroscopy to identify the quarry that was the source of granite found in ancient Roman ruins — spectroscopy See how gamma-ray spectroscopy is used to identify the quarry that was the source of granite found in ancient Roman ruins.

Infrared (IR) spectroscopy is a versatile analytical technique capable of examining a wide variety of samples, including liquids, gases, and thin films of solids.1

The method is particularly powerful for analyzing organic compounds because the stretching and bending vibrations of their chemical bonds interact with infrared radiation, providing detailed structural data and allowing for the identification of specific functional groups. Beyond basic chemical analysis, IR spectroscopy is used to determine the composition, origin, and age of archaeological specimens and is employed to detect forgeries in art and other objects.23

Depending on the sample state, different techniques are used:
* Transmission: Used for liquids, gases, and thin solid films. These samples must be contained in cells with infrared-transmitting windows, such as sodium chloride, potassium bromide, or cesium iodide.1
* Reflection: Used for examining solids, films, and coatings by reflecting radiation off the sample surface.1