Introduction to Lambert-Beer Law

The Lambert-Beer law, also known as Beer's law, is the basic law of spectrophotometry. It describes the relationship between the intensity of light absorption by a substance at a certain wavelength and the concentration of the absorbing substance and the thickness of the liquid layer. It applies to all electromagnetic radiation and absorbing substances, including gases, solids, liquids, molecules, atoms, and ions. The Beer-Lambert law is the theoretical basis for colorimetric analysis and spectrophotometry. The amount of light absorbed is proportional to the number of absorbing molecules in the optical path.