Absorption spectroscopy: Difference between revisions

From WikiMD's Wellness Encyclopedia

CSV import
 
CSV import
 
(One intermediate revision by the same user not shown)
Line 1: Line 1:
{{Short description|Technique for measuring the absorption of radiation by a sample}}
Absorption spectroscopy


'''Absorption spectroscopy''' is a technique used in [[analytical chemistry]] to determine the presence and concentration of a substance in a sample by measuring the amount of light absorbed by the sample. This method is based on the principle that atoms and molecules absorb light at specific wavelengths, which correspond to the energy differences between their electronic, vibrational, or rotational states.
[[File:Spectroscopy overview.svg|thumb|right|Overview of different types of spectroscopy, including absorption spectroscopy.]]
 
'''Absorption spectroscopy''' is a technique used in [[analytical chemistry]] to determine the presence and concentration of a substance in a sample by measuring the amount of light absorbed by the sample. This method is based on the principle that atoms and molecules absorb light at specific wavelengths, which correspond to the energy differences between their electronic states.


==Principles of Absorption Spectroscopy==
==Principles of Absorption Spectroscopy==
Absorption spectroscopy involves the interaction of light with matter. When light passes through a sample, certain wavelengths are absorbed by the sample, while others are transmitted. The amount of light absorbed at each wavelength is measured and used to create an [[absorption spectrum]]. This spectrum can provide information about the sample's composition and concentration.
Absorption spectroscopy involves the interaction of light with matter. When light passes through a sample, certain wavelengths are absorbed by the sample's atoms or molecules. The amount of light absorbed at each wavelength is measured and used to create an [[absorption spectrum]]. This spectrum can be used to identify the substance and determine its concentration.


The basic principle of absorption spectroscopy is described by [[Beer-Lambert law]], which relates the absorption of light to the properties of the material through which the light is traveling. The law is expressed as:
The basic components of an absorption spectrometer include a light source, a sample holder, a monochromator to select specific wavelengths of light, and a detector to measure the intensity of transmitted light.


: ''A = _lc''
==Types of Absorption Spectroscopy==
There are several types of absorption spectroscopy, each suited to different applications:


where ''A'' is the absorbance, ''_'' is the molar absorptivity, ''l'' is the path length of the sample, and ''c'' is the concentration of the absorbing species.
* '''[[Ultraviolet-visible spectroscopy|UV-Vis spectroscopy]]''': Measures absorption in the ultraviolet and visible regions of the electromagnetic spectrum. It is commonly used for quantitative analysis of solutions.
* '''[[Infrared spectroscopy|IR spectroscopy]]''': Measures absorption in the infrared region, providing information about molecular vibrations and structure.
* '''[[Atomic absorption spectroscopy|Atomic absorption spectroscopy (AAS)]]''': Used to analyze metal ions in solutions by measuring the absorption of light by free atoms.


==Types of Absorption Spectroscopy==
==Applications==
Absorption spectroscopy can be classified based on the type of radiation used and the nature of the transitions involved:
Absorption spectroscopy is widely used in various fields, including:


===Ultraviolet-Visible (UV-Vis) Spectroscopy===
* [[Environmental science]]: Monitoring pollutants in air and water.
[[UV-Vis spectroscopy]] involves the absorption of ultraviolet or visible light by molecules, leading to electronic transitions. It is widely used for quantitative analysis of solutions and for studying the electronic structure of molecules.
* [[Pharmaceutical industry]]: Quality control and drug development.
* [[Astronomy]]: Identifying elements in stars and planets.


===Infrared (IR) Spectroscopy===
[[File:Sodium in atmosphere of exoplanet HD 209458.jpg|thumb|right|Detection of sodium in the atmosphere of exoplanet HD 209458 using absorption spectroscopy.]]
[[Infrared spectroscopy]] measures the absorption of infrared radiation by molecules, which causes vibrational transitions. It is commonly used to identify functional groups in organic compounds and to study molecular vibrations.


===Nuclear Magnetic Resonance (NMR) Spectroscopy===
==Astronomical Applications==
[[NMR spectroscopy]] is based on the absorption of radiofrequency radiation by nuclei in a magnetic field. It provides detailed information about the structure, dynamics, and environment of molecules.
In [[astronomy]], absorption spectroscopy is used to study the composition of [[stars]], [[planets]], and other celestial bodies. By analyzing the absorption lines in the spectra of stars, astronomers can determine the elements present in their atmospheres.


===Atomic Absorption Spectroscopy (AAS)===
[[File:Fraunhofer lines.svg|thumb|right|Fraunhofer lines in the solar spectrum, an example of absorption lines.]]
[[Atomic absorption spectroscopy]] is used to determine the concentration of metal ions in solutions. It involves the absorption of light by free atoms in the gaseous state.


==Applications==
==Spectral Lines==
Absorption spectroscopy is used in various fields, including:
Absorption lines, such as the [[Fraunhofer lines]] in the solar spectrum, are dark lines that appear in the spectrum when light is absorbed by atoms or molecules. These lines are characteristic of specific elements and can be used to identify them.


* [[Environmental science]]: Monitoring pollutants and analyzing water quality.
==Gallery==
* [[Pharmaceutical industry]]: Determining the concentration of drugs and active ingredients.
<gallery>
* [[Biochemistry]]: Studying proteins, nucleic acids, and other biomolecules.
File:Emission spectrum-Fe.svg|Emission spectrum of iron, showing lines that correspond to absorption lines.
* [[Astronomy]]: Analyzing the composition of stars and planets by studying their absorption spectra.
File:Identification of Ices in the Solar System.jpg|Identification of ices in the solar system using absorption spectroscopy.
File:Cumulative-absorption-spectrum-hubble-telescope.jpg|Cumulative absorption spectrum from the Hubble Space Telescope.
</gallery>


==Related pages==
==Related Pages==
* [[Spectroscopy]]
* [[Spectroscopy]]
* [[Emission spectroscopy]]
* [[Emission spectroscopy]]
Line 41: Line 47:
* [[Raman spectroscopy]]
* [[Raman spectroscopy]]


==Gallery==
[[Category:Spectroscopy]]
[[Category:Analytical chemistry]]
[[Category:Astronomical spectroscopy]]
== Absorption_spectroscopy ==
<gallery>
<gallery>
File:Spectroscopy overview.svg|Overview of different types of spectroscopy.
File:Spectroscopy_overview.svg|Overview of spectroscopy techniques
File:Sodium in atmosphere of exoplanet HD 209458.jpg|Detection of sodium in the atmosphere of an exoplanet using absorption spectroscopy.
File:Sodium_in_atmosphere_of_exoplanet_HD_209458.jpg|Sodium in the atmosphere of exoplanet HD 209458
File:Fraunhofer lines.svg|Fraunhofer lines in the solar spectrum, an example of absorption lines.
File:Fraunhofer_lines.svg|Fraunhofer lines in the solar spectrum
File:Emission spectrum-Fe.svg|Emission spectrum of iron, showing lines that correspond to absorption lines.
File:Emission_spectrum-Fe.svg|Emission spectrum of iron (Fe)
File:Identification of Ices in the Solar System.jpg|Use of absorption spectroscopy to identify ices in the solar system.
File:Identification_of_Ices_in_the_Solar_System.jpg|Identification of ices in the Solar System
File:Cumulative-absorption-spectrum-hubble-telescope.jpg|Cumulative absorption spectrum from the Hubble Space Telescope.
File:Cumulative-absorption-spectrum-hubble-telescope.jpg|Cumulative absorption spectrum from the Hubble Telescope
</gallery>
</gallery>
[[Category:Spectroscopy]]

Latest revision as of 11:08, 18 February 2025

Absorption spectroscopy

Overview of different types of spectroscopy, including absorption spectroscopy.

Absorption spectroscopy is a technique used in analytical chemistry to determine the presence and concentration of a substance in a sample by measuring the amount of light absorbed by the sample. This method is based on the principle that atoms and molecules absorb light at specific wavelengths, which correspond to the energy differences between their electronic states.

Principles of Absorption Spectroscopy[edit]

Absorption spectroscopy involves the interaction of light with matter. When light passes through a sample, certain wavelengths are absorbed by the sample's atoms or molecules. The amount of light absorbed at each wavelength is measured and used to create an absorption spectrum. This spectrum can be used to identify the substance and determine its concentration.

The basic components of an absorption spectrometer include a light source, a sample holder, a monochromator to select specific wavelengths of light, and a detector to measure the intensity of transmitted light.

Types of Absorption Spectroscopy[edit]

There are several types of absorption spectroscopy, each suited to different applications:

  • UV-Vis spectroscopy: Measures absorption in the ultraviolet and visible regions of the electromagnetic spectrum. It is commonly used for quantitative analysis of solutions.
  • IR spectroscopy: Measures absorption in the infrared region, providing information about molecular vibrations and structure.
  • Atomic absorption spectroscopy (AAS): Used to analyze metal ions in solutions by measuring the absorption of light by free atoms.

Applications[edit]

Absorption spectroscopy is widely used in various fields, including:

Detection of sodium in the atmosphere of exoplanet HD 209458 using absorption spectroscopy.

Astronomical Applications[edit]

In astronomy, absorption spectroscopy is used to study the composition of stars, planets, and other celestial bodies. By analyzing the absorption lines in the spectra of stars, astronomers can determine the elements present in their atmospheres.

Error creating thumbnail:
Fraunhofer lines in the solar spectrum, an example of absorption lines.

Spectral Lines[edit]

Absorption lines, such as the Fraunhofer lines in the solar spectrum, are dark lines that appear in the spectrum when light is absorbed by atoms or molecules. These lines are characteristic of specific elements and can be used to identify them.

Gallery[edit]

  • Emission spectrum of iron, showing lines that correspond to absorption lines.
    Emission spectrum of iron, showing lines that correspond to absorption lines.
  • Identification of ices in the solar system using absorption spectroscopy.
    Identification of ices in the solar system using absorption spectroscopy.
  • Cumulative absorption spectrum from the Hubble Space Telescope.
    Cumulative absorption spectrum from the Hubble Space Telescope.

Related Pages[edit]

Absorption_spectroscopy[edit]

  • Overview of spectroscopy techniques
    Overview of spectroscopy techniques
  • Sodium in the atmosphere of exoplanet HD 209458
    Sodium in the atmosphere of exoplanet HD 209458
  • Fraunhofer lines in the solar spectrum
    Fraunhofer lines in the solar spectrum
  • Emission spectrum of iron (Fe)
    Emission spectrum of iron (Fe)
  • Identification of ices in the Solar System
    Identification of ices in the Solar System
  • Cumulative absorption spectrum from the Hubble Telescope
    Cumulative absorption spectrum from the Hubble Telescope
Retrieved from "https://wikimd.com/index.php?title=Absorption_spectroscopy&oldid=6321830"