Extremely high resolution spectrum of the Sun showing thousands of elemental absorption lines (fraunhofer lines)

Spectroscopy is the study of spectra, that is, the dependence of physical quantities on frequency. Image File history File links Download high resolution version (8192x5464, 2848 KB)A high resolution version of the spectrum of the Sun, this image was created from a digital atlas observed with the Fourier Transform Spectrometer at the McMath-Pierce Solar Facility at Kitt Peak National Observatory, near Tucson, Arizona... Image File history File links Download high resolution version (8192x5464, 2848 KB)A high resolution version of the spectrum of the Sun, this image was created from a digital atlas observed with the Fourier Transform Spectrometer at the McMath-Pierce Solar Facility at Kitt Peak National Observatory, near Tucson, Arizona... Solar Fraunhofer lines In physics and optics, the Fraunhofer lines are a set of spectral lines named for the German physicist Joseph von Fraunhofer (1787--1826). ... In mathematics, physics and signal processing, the frequency spectrum is a representation of a signal or other function in terms of frequency (in the frequency domain). It is the projection of the function onto a set of sinusoidal basis functions. ... Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...

Spectroscopy is often used in physical and analytical chemistry for the identification of substances, through the spectrum emitted or absorbed. A device for recording a spectrum is a spectrometer. Spectroscopy can be classified according to the physical quantity which is measured or calculated or the measurement process. Chemistry (in Greek: χημεία) is the science of matter that deals with the composition, structure, and properties of substances and with the transformations that they undergo. ... Jump to: navigation, search This article needs to be cleaned up to conform to a higher standard of quality. ...

Spectroscopy is also heavily used in astronomy. Most large telescopes have spectrographs, which are used either to measure the chemical composition and physical properties of astronomical objects or to measure their velocities from the Doppler shift of spectral lines. Astrometry: the study of the position of objects in the sky and their changes of position. ... The Doppler effect is the apparent change in frequency or wavelength of a wave that is perceived by an observer moving relative to the source of the waves. ...

Physical quantity measured

The type of spectroscopy depends on the physical quantity measured. Normally, the quantity that is measured is an amount or intensity of something.

• The intensity of emitted electromagnetic radiation and the amount of absorbed electromagnetic radiation are studied by electromagnetic spectroscopy (see also cross section).
• The amplitude of macroscopic vibrations is studied by acoustic spectroscopy and dynamic mechanical spectroscopy.
• Kinetic energy of particles is studied by electron energy loss spectroscopy and Auger electron spectroscopy (see also cross section).
• The mass-to-charge ratios of molecules and atoms are studied in mass spectrometry. A mass spectrometer does not measure the kinetic energy of particles - all particles have the same known kinetic energy (or an integer multiple thereof, depending on the charge) - so it is disputable whether this field strictly is a type of spectroscopy.
• The number of molecules or atoms or quantum-mechanical states to which the frequency or energy parameter applies. In this case the spectra is usually called cross section.

Jump to: navigation, search Electromagnetic radiation can be conceptualized as a self propagating transverse oscillating wave of electric and magnetic fields. ... Jump to: navigation, search Electromagnetic radiation can be conceptualized as a self propagating transverse oscillating wave of electric and magnetic fields. ... Electromagnetic spectroscopy a. ... Cross section may refer to the following In geometry, Cross section is the intersection of a 3-dimensional body with a plane. ... In the technique of Dynamic Mechanical Spectroscopy a material (usually a slab of polymer) is exposed to a periodical deformation. ... In electron energy loss spectroscopy a material is exposed to a beam of electrons with a known, narrow range of kinetic energies. ... Jump to: navigation, search Auger electron spectroscopy is an analytical technique in surface chemistry and materials science. ... Cross section may refer to the following In geometry, Cross section is the intersection of a 3-dimensional body with a plane. ... Jump to: navigation, search A molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... Jump to: navigation, search Properties For alternative meanings see atom (disambiguation). ... Mass spectrometry is a technique for separating ions by their mass-to-charge (m/z) ratios. ... Cross section may refer to the following In geometry, Cross section is the intersection of a 3-dimensional body with a plane. ...

Measurement process

Different types of spectroscopy use different measurement processes:

Three main types of spectroscopy

Absorption spectroscopy uses the range of electromagnetic spectra in which a substance absorbs. In atomic absorption spectroscopy, the sample is atomized and then light of a particular frequency is passed through the vapour. After calibration, the amount of absorption can be related to the concentrations of various metal ions through the Beer-Lambert law. The method can be automated and is widely used to measure concentrations of ions such as sodium and calcium in blood. Other types of spectroscopy may not require sample atomization. For example, ultraviolet/visible (UV/ Vis) absorption spectroscopy is most often performed on liquid samples to detect molecular content and infrared (IR) spectroscopy is most often performed on liquid, semi-liquid (paste or grease), dried, or solid samples to determine molecular information, including structural information. Absorption spectroscopy is an analytical tool used by chemists. ... Jump to: navigation, search In optics, the Beer-Lambert law, also known as Beers law or the Beer-Lambert-Bouguer law is an empirical relationship in relating the absorption of light to the properties of the material through which the light is travelling. ... Jump to: navigation, search General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ... Jump to: navigation, search General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... IR spectrum of a thin film of liquid ethanol. ...

Emission spectroscopy uses the range of electromagnetic spectra in which a substance radiates. The substance first absorbs energy and then radiates this energy as light. This energy can be from a variety of sources, including collision (either due to high temperatures or otherwise), chemical reactions, and light.

Scattering spectroscopy measures certain physical properties by measuring the amount of light that a substance scatters at cetain wavelengths, incident angles, and polarization angles. Scattering spectroscopy differs from emission spectroscopy due to the fact that the scattering process is much faster than the absorption/emission process. One of the most useful applications of light scattering spectroscopy is Raman spectroscopy. Raman spectroscopy is a spectroscopic technique used in condensed matter physics and chemistry to study vibrational, rotational, and other low-frequency modes in a system. ...

Common types of spectroscopy

Spectrum of fluorescent lights showing prominent mercury peaks.

Fluorescence spectroscopy Fluorescence spectroscopy uses higher energy photons to excite a sample, which will then emit lower energy photons. This technique has become popular for its biochemical and medical applications, and can be used for confocal microscopy, fluorescence resonance energy transfer, and fluorescence lifetime imaging. Image File history File links Download high resolution version (1268x777, 18 KB)Spectrum with peaks labelled taken with an Ocean Optics spectrometer [1] of ambient light provided by fluorecent lamps. ... Image File history File links Download high resolution version (1268x777, 18 KB)Spectrum with peaks labelled taken with an Ocean Optics spectrometer [1] of ambient light provided by fluorecent lamps. ... A compact fluorescent lamp with an integrated electronic ballast A fluorescent lamp is a type of lamp that uses electricity to excite mercury vapor in argon or neon gas, producing short-wave ultraviolet light. ... Fluorescence spectroscopy or fluorometry is a type of electromagnetic spectroscopy used for analyzing fluorescent spectra. ... In physics, the photon (from Greek φοτος, meaning light) is a quantum of excitation of the quantised electromagnetic field and is one of the elementary particles studied by quantum electrodynamics (QED) which is the oldest part of the Standard Model of particle physics. ... Confocal laser scanning microscopy (CLSM or LSCM) is a valuable tool for obtaining high resolution images and 3-D reconstructions. ... Fluorescence resonance energy transfer (or Förster resonance energy transfer) describes an energy transfer mechanism between two fluorescent molecules. ... Fluorescence lifetime imaging is a confocal microscopy technique for producing an image based on the differences in the exponential decay rate of the fluorescence from a fluorescent sample. ...

X-ray spectroscopy and X-ray crystallography When X-rays of sufficient frequency (energy) interact with a substance, inner shell electrons in the atom are excited to outer empty orbitals, or they may be removed completely, ionizing the atom. The inner shell "hole" will then be filled by electrons from outer orbitals. The energy available in this de-excitation process is emitted as radiation (fluorescence) or will remove other less-bound electrons from the atom (Auger effect). The absorption or emission frequencies (energies) are characteristic of the specific atom. In addition, for a specific atom small frequency (energy) variations occur which are characteristic of the chemical bonding. With a suitable apparatus, these characteristic X-ray frequencies or Auger electron energies can be measured. X-ray absorption and emission spectroscopy is used in chemistry and material sciences to determine elemental composition and chemical bonding. In modern X-ray emission spectroscopy, X-rays are used to excite a material of interest. ... X-ray crystallography is a technique in crystallography in which the pattern produced by the diffraction of X-rays through the closely spaced lattice of atoms in a crystal is recorded and then analyzed to reveal the nature of that lattice. ...

X-ray crystallography is a process in which X-rays are shone onto crystals at a certain angle. The wavelength of the X-rays is known and so the distance apart of the crystal planes can be calculated. Combining all information enables crystal structure to be detected.

Flame Spectroscopy

Liquid solution samples are aspirated into a burner or nebulizer/burner combination, desolvated, atomized, and sometimes excited to a higher energy electronic state. The use of a flame during analysis requires fuel and oxidant, typically in the form of gases. Common fuel gases used are acetylene or hydrogen. Common oxidant gases used are oxygen, air, or nitrous oxide. These methods are often capable of analyzing metallic element analytes in the part per million, billion, or possibly lower concentration ranges. Light detectors are needed to detect light with the analysis information coming from the flame. The chemical compound acetylene, also called ethyne, was discovered in 1836 by Edmund Davy, in England; its chemical formula is C2H2 and its structure is: Acetylene is a colorless and extremely flammable gas at standard temperature and pressure, with a melting point of -80. ... Jump to: navigation, search General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Jump to: navigation, search General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Jump to: navigation, search Air is a name for the mixture of gases present in the Earths atmosphere. ... Jump to: navigation, search Nitrous oxide, also known as dinitrogen oxide or dinitrogen monoxide, is a chemical compound with chemical formula N2O. Under room conditions it is a colourless non-flammable gas, with a pleasant, slightly sweet odor. ... Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ... Jump to: navigation, search Concentration is a very common concept used in chemistry and related fields. ...

• Atomic Emission Spectroscopy - This method uses flame excitation; atoms are excited from the heat of the flame to emit light. This method commonly uses a total consumption burner with a round burning outlet. A higher temperature flame than atomic absorption spectroscopy (AA) is typically used to produce excitation of analyte atoms. Since analyte atoms are excited by the heat of the flame, no special elemental lamps to shine into the flame are needed. A high resolution polychromator can be used produce an emission intensity vs. wavelength spectrum over a range of wavelengths showing multiple element excitation lines, meaning multiple elements can be detected in one run. Alternatively, a monochromator can be set at one wavelength to concentrate on analysis of a single element at a certain emission line. Plasma emission spectroscopy is a more modern version of this method. See Flame emission spectroscopy for more details.
• Atomic absorption spectroscopy (often called AA) - This method commonly uses a pre-burner nebulizer (or nebulizing chamber) to create a sample mist and a slot-shaped burner which gives a longer pathlength flame. The temperature of the flame is low enough that the flame itself does not excite sample atoms from their ground state. The nebulizer and flame are used to desolvate and atomize the sample, but the excitation of the analyte atoms is done by the use of lamps shining through the flame at various wavelengths for each type of analyte. In AA, the amount of light absorbed after going through the flame determines the amount of analyte in the sample. A graphite furnace for heating the sample to desolvate and atomize is commonly used for greater sensitivity. The graphite furnace method can also analyze some solid or slurry samples. Because of its good sensitivity and selectivity, it is still a commonly used method of analysis for certain trace elements in aqueous (and other liquid) samples.
• Atomic Fluorescence Spectroscopy - This method commonly uses a burner with a round burning outlet. The flame is used to solvate and atomize the sample, but a lamp shines light at a specific wavelength into the flame to excite the analyte atoms in the flame. The atoms of certain elements can then fluoresce emitting light in a different direction. The intensity of this fluorescing light is used for quantifying the amount of analyte element in the sample. A graphite furnace can also be used for atomic fluorescence spectroscopy. This method is not as commonly used as atomic absorption or plasma emission spectroscopy.

Jump to: navigation, search The wavelength is the distance between repeating units of a wave pattern. ... A monochromator is an optical device that transmits a mechanically selectable narrow band of wavelengths of light chosen from a wider range of wavelengths available at the input. ... Flame Emission Spectroscopy (FES) is a form of emission spectroscopy in which energy is provided to a sample through use of a flame. ... Atomic absorption spectroscopy in analytical chemistry is a technique for determining the concentration of a particular metal element within a sample. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized cadmium selenide (CdSe) quantum dots. ...

Plasma Emission spectroscopy

- in some ways similar to flame atomic emission spectroscopy, it has largely replaced it.

• Direct-current plasma (DCP)

• Inductively-coupled plasma (ICP)

• Laser induced breakdown spectroscopy (LIBS)

• Laser-induced plasma

• Microwave-induced plasma (MIP)

Spark or arc (emission) spectroscopy - can be used for the analysis of metallic elements in solid samples. In traditional arc spectroscopy methods, a sample of the solid was commonly ground up and destroyed during analysis. An electric arc or spark is passed through the sample, heating the sample to a high temperature to excite the atoms in it. The excited analyte atoms glow emitting light at various wavelengths which could be detected by common spectroscopic methods. Since the conditions producing the arc emission typically are not controlled quantitatively, the analysis for the elements is qualitative. An inductively coupled plasma (ICP) is a type of plasma source in which the energy is supplied by electrical currents which are produced by electromagnetic induction, that is, by time-varying magnetic fields. ... Laser Induced Breakdown Spectroscopy (LIBS) is a type of atomic emission spectroscopy which utilises a highly energetic laser pulse as the excitation source. ...

Visible spectroscopy

Many atoms emit or absorb visible light. In order to obtain a fine line spectrum, the atoms must be in a gas phase. This means that the substance has to be vaporised. Spectrum is studied in absorption or emission.

UV spectroscopy

All atoms absorb in the UV region because photons are energetic enough to excite outer electrons. If the frequency is high enough, Photoionisation takes place. Photoionisation is a physical process in which a photon strikes an atom, ion or molecule, resulting in the ejection of an electron. ...

Infra-red spectroscopy

In Organic chemistry different types of interatomic bond vibrate at different frequencies in the infra-red part of the spectrum. The analysis of IR absorption spectra shows what type of bonds are present in the sample. Jump to: navigation, search Organic chemistry is the scientific study of the structure, properties, composition, reactions, and synthesis of organic compounds that by definition contain carbon. ... Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation. ...

Nuclear Magnetic Resonance spectroscopy

NMR spectroscopy analyzes certain atomic nuclei to determine different local environments of hydrogen, carbon, or other atoms in the molecule of an organic compound or other compound. This is used to help determine the structure of the compound. Nuclear Magnetic Resonance Spectroscopy is the name given to the technique which exploits the magnetic properties of nuclei. ... Jump to: navigation, search General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Jump to: navigation, search General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... Jump to: navigation, search A molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... An organic compound is any member of a large class of chemical compounds whose molecules contain carbon, with exception of carbides, carbonates, carbon oxides and gases containing carbon. ... ... Chemical structure is the arrangement of atoms within a molecule, usually linked by covalent bonds. ...

Photoemission spectroscopy

An article on X-ray photoelectron spectroscopy that complements this article is located elsewhere. ...

Less frequently used / combined spectroscopy

• Raman spectroscopy uses the inelastic scattering of light to analyse vibrational and rotational modes of molecules. The resulting 'fingerprints' are an aid to analysis.
• Fourier transform is an efficient method for collecting various spectra. The use of Fourier transform in spectroscopy is called Fourier transform spectroscopy. Nearly all infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy are performed with Fourier transforms.
• Spectroscopy of matter in situations where the properties are changing with time is called Time-resolved spectroscopy.
• Spectroscopy using an AFM-based analytical technique is called Force spectroscopy.
• Dielectric spectroscopy
• Circular Dichroism spectroscopy

Raman spectroscopy is a spectroscopic technique used in condensed matter physics and chemistry to study vibrational, rotational, and other low-frequency modes in a system. ... The Fourier transform, named after Joseph Fourier, is an integral transform that re-expresses a function in terms of sinusoidal basis functions, i. ... FTIR of a thin film of ethanol in the liquid phase. ... Pacific Northwest National Laboratorys high magnetic field (800 MHz) NMR spectrometer being loaded with sample. ... In physics and physical chemistry, time-resolved spectroscopy is the study of dynamical processes in materials or chemical compounds by means of spectroscopic techniques. ... The atomic force microscope (AFM) is a very powerful microscope invented by Binnig, Quate and Gerber in 1986. ... Force spectroscopy is a dynamic analytical technique that allows the study of the mechanical properties of polymer molecules and/or chemical bonds. ... Dielectric spectroscopy (sometimes called impedance spectroscopy) measures the dielectric properties of a medium as a function of frequency. ... Circular dichroism, or CD, is defined as the differential absorption of left and right hand circularly polarized light. ...

See also

• Atomic spectroscopy
• Astronomical spectroscopy
• Diffuse Reflectance Spectroscopy
• Rotational spectroscopy
• Vibrational spectroscopy
• Infrared spectroscopy
• Rigid rotor
• EPR spectroscopy
• Spectral power distributions
• Metamerism (color)
• Spectral reflectance
• Spectrophotometry
• Laser Induced Breakdown Spectroscopy (LIBS)
• Cross section
• Scattering theory
• UV/VIS spectroscopy

Atomic spectroscopy is the determination of elemental composition by its electromagnetic or mass spectrum. ... High resolution spectrum of the Sun showing thousands of elemental absorption lines (fraunhofer lines). ... Rotational spectroscopy studies the absorption of electromagnetic radiation (typically in the microwave region of the spectrum) by molecules. ... The vibrational states of a molecule can be probed in a variety of ways. ... IR spectrum of a thin film of liquid ethanol. ... The rigid rotor is a mechanical model that is used to explain rotating systems. ... Electron Paramagnetic Resonance (EPR) or Electron Spin Resonance (ESR) is a spectroscopic technique which detects species that have unpaired electrons, generally meaning that it must be a free radical, if it is an organic molecule, or that it has transition metal ions if it is an inorganic complex. ... The spectral power distribution (SPD) of a light source is a measurement of the energy output at points (usually 31) along the visible spectrum. ... Metamerism is a psychophysical phenomenon commonly defined incompletely as two samples which match when illuminated by a particular light source and then do not match when illuminated by a different light source. ... Spectral reflectance curves are generated by spectrophotometers. ... Jump to: navigation, search In physics, spectrophotometry is the quantitative study of electromagnetic spectra. ... Schematic LIBS Setup () Laser Induced Breakdown Spectroscopy (LIBS) is a type of atomic emission spectroscopy which utilises a highly energetic laser pulse as the excitation source. ... Cross section may refer to the following In geometry, Cross section is the intersection of a 3-dimensional body with a plane. ... Scattering theory is a branch of physics and especially of quantum mechanics whose aim is the study of scattering events. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ...

External links

• The Science of Spectroscopy - supported by NASA, includes OpenSpectrum, a Wiki-based learning tool for spectroscopy that anyone can edit

• Atomic Emission Spectroscopy

• A Short Study of the Chraracteristics of two Lab Spectroscopes