Dictionary > Beer-Lambert law

Beer-Lambert law

Definition
noun
The principal law in spectrometry in which it states that the absorbance at a given wavelength of light is proportional to the molar extinction coefficient, the concentration of absorbers in the sample of the molar solution, and the length of the light path
Supplement
According to the Beer-Lambert law, the absorbance at a given wavelength of light (A) is proportional to the molar extinction coefficient (E), the concentration of absorbers in the sample of the molar solution (C), and the length of the light path (L), thus, the equation, A = ECL. Or, simply put, the concentration of a substance in moles is proportional to the absorption of a given wavelength of light by a solution of the substance. It is regarded as the principal law in spectrometry1, and is used in the study of spectroscopy.
The law was discovered by Pierre Bouguer and attributed to Johann Heinrich Lambert. August Beer extended the exponential attenuation law by including the concentration of solutions in the attenuation coefficient.2
Also called:

  • Lambert–Beer law
  • Beer–Lambert–Bouguer law

See also:

  • spectrometry
  • Molar absorption coefficient
  • Extinction coefficient
  • Molar absorptivity
  • Molar extinction coefficient
  • Molar absorbancy index
  • Reference(s):

    1 Svanberg, S. (2004). Atomic and molecular spectroscopy : basic aspects and practical applications. Berlin New York: Springer.

    1 Beer (1852) “Bestimmung der Absorption des rothen Lichts in farbigen Flüssigkeiten” (Determination of the absorption of red light in colored liquids), Annalen der Physik und Chemie, vol. 86, pp. 78–88.


    You will also like...

    Hominid
    The Hominids

    The hominid family diversified from the apes around 6 to 8 million years ago. Since then, the evolutionary path has prov..

    Water Cycle
    The Water Cycle

    The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..

    Muscle
    Muscle

    Muscle cells are specialized to generate force and movement. Learn about the different types of muscle tissues in this t..

    Freshwater lake ecosystem
    Freshwater Producers and Consumers

    Freshwater ecosystem is comprised of four major constituents, namely elements and compounds, plants, consumers, and deco..

    Endemic Flora of New Zealand
    New Zealand’s Unique Flora

    If New Zealand has lots of unique animals, it's also got a whole lot of unique plants. Find out more about some of them,..

    Salmon jumping upstream in the river
    Lotic Communities & Animals

    A running water environment offers numerous microhabitats for many types of animals. Similar to plants, animals in lotic..