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  2. Molar absorption coefficient - Wikipedia

    en.wikipedia.org/wiki/Molar_absorption_coefficient

    The absorbance of a material that has only one absorbing species also depends on the pathlength and the concentration of the species, according to the Beer–Lambert law =, where ε is the molar absorption coefficient of that material; c is the molar concentration of those species; ℓ is the path length.

  3. Beer–Lambert law - Wikipedia

    en.wikipedia.org/wiki/Beer–Lambert_law

    Beer's law states that a beam of visible light passing through a chemical solution of fixed geometry experiences absorption proportional to the solute concentration. Other applications appear in physical optics , where it quantifies astronomical extinction and the absorption of photons , neutrons , or rarefied gases .

  4. Absorbance - Wikipedia

    en.wikipedia.org/wiki/Absorbance

    Absorbance is defined as "the logarithm of the ratio of incident to transmitted radiant power through a sample (excluding the effects on cell walls)". [1] Alternatively, for samples which scatter light, absorbance may be defined as "the negative logarithm of one minus absorptance, as measured on a uniform sample". [2]

  5. Variable pathlength cell - Wikipedia

    en.wikipedia.org/wiki/Variable_pathlength_cell

    Variable pathlength absorption spectroscopy uses a determined slope to calculate concentration. As stated above this is a product of the molar absorptivity and the concentration. Since the actual absorbance value is taken at many data points at equal intervals, background subtraction is generally unnecessary.

  6. Atomic absorption spectroscopy - Wikipedia

    en.wikipedia.org/wiki/Atomic_absorption_spectroscopy

    In analytical chemistry the technique is used for determining the concentration of a particular element (the analyte) in a sample to be analyzed. AAS can be used to determine over 70 different elements in solution, or directly in solid samples via electrothermal vaporization, [ 1 ] and is used in pharmacology , biophysics , archaeology and ...

  7. Extinction coefficient - Wikipedia

    en.wikipedia.org/wiki/Extinction_coefficient

    Extinction coefficient refers to several different measures of the absorption of light in a medium: Attenuation coefficient, sometimes called "extinction coefficient" in meteorology or climatology Mass extinction coefficient, how strongly a substance absorbs light at a given wavelength, per mass density

  8. Molar concentration - Wikipedia

    en.wikipedia.org/wiki/Molar_concentration

    Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. [2] For use in broader applications, it is defined as amount of substance of solute per unit volume of solution, or per unit volume available to the species, represented by lowercase c {\displaystyle c} : [ 3 ]

  9. Colorimeter (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Colorimeter_(chemistry)

    A colorimeter is a device used in colorimetry that measures the absorbance of particular wavelengths of light by a specific solution. [1] [2] It is commonly used to determine the concentration of a known solute in a given solution by the application of the Beer–Lambert law, which states that the concentration of a solute is proportional to the absorbance.