What is the principle of absorption spectroscopy?

Absorption spectroscopy is a widely used analytical technique that measures the absorption of electromagnetic radiation (such as light) by a substance. The principle of absorption spectroscopy is based on the interaction between electromagnetic radiation and matter. When electromagnetic radiation passes through a sample, certain wavelengths are absorbed by the sample while others pass through unaffected.

The absorption of radiation occurs because the energy of the incoming photons matches the energy required to excite electrons in the atoms or molecules of the sample from lower energy states to higher energy states. This absorption results in a decrease in the intensity of the transmitted radiation at specific wavelengths, which corresponds to the characteristic absorption spectrum of the sample.

The absorption spectrum provides valuable information about the chemical composition, molecular structure, and concentration of substances in the sample. By measuring the intensity of absorbed radiation at different wavelengths, researchers can identify substances and quantify their concentrations. Absorption spectroscopy is used in various fields including chemistry, biochemistry, environmental science, and medicine for analysis and characterization of samples.