Forensic Chemistry – Universal absorption spectroscopy principle

The light and matter relationship gives rise to a specific term known as absorption spectroscopy. Energy in the form of radiation that enters a sample is trapped by the molecules there.

• Factors affecting the amount of absorption

The amount of absorption is affected by the following factor:

• the light’s energy:
• the types and numbers of molecules in the sample.
• Working principle of absorption spectroscopy

Light intensity is measured both in presence and absence of  sample. The difference between the two intensities can give us information that, how much light is absorbed by the sample. The amount of light absorbed by the sample at each wavelength or frequency is plotted to form the absorption spectrum.

• Uses of absorption spectroscopy

Absorption spectroscopy can be applicable:

• to detect and characterise the chemical constituents of a material.
• As well as its concentration in a sample.

. Many materials absorb light at different wavelengths, which is used to identify specific molecules or chemical groups in a sample.

• Types of Absorption spectroscopy

Absorption spectroscopy include various types and methods, each with unique principles and uses, such as:

• UV-visible spectroscopy.
• infrared spectroscopy.
• and atomic absorption spectroscopy.