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Atomic absorption spectroscopy (AAS) is a spectroanalytical procedure for the quantitative measurement of chemical elements. AAS is based on the absorption of light by free metallic ions that have been atomized from a sample.
GFAA spectrometry instruments have the following basic features: 1. a source of light (lamp) that emits resonance line radiation; 2. an atomization chamber (graphite tube) in which the sample is vaporized; 3. a monochromator for selecting only one of the characteristic wavelengths (visible or ultraviolet) of the element of interest; 4. a detector, generally a photomultiplier tube (light ...
In atomic absorption spectroscopy, light of a predetermined wavelength is passed through a collection of atoms. If the wavelength of the source light has energy corresponding to the energy difference between two energy levels in the atoms, a portion of the light will be absorbed.
Saturated absorption spectroscopy measures the transition frequency of an atom or molecule between its ground state and an excited state.In saturated absorption spectroscopy, two counter-propagating, overlapped laser beams are sent through a sample of atomic gas.
For atoms in the gas phase the principal effects are Doppler and pressure broadening. Lines are relatively sharp on the scale of measurement so that applications such as atomic absorption spectroscopy (AAS) and Inductively coupled plasma atomic emission spectroscopy (ICP) are used for elemental analysis. Atoms also have distinct x-ray spectra ...
Atomic absorption spectroscopy and atomic emission spectroscopy involve visible and ultraviolet light. These absorptions and emissions, often referred to as atomic spectral lines, are due to electronic transitions of outer shell electrons as they rise and fall from one electron orbit to another.
Ultraviolet-visible (UV-vis) spectroscopy involves energy levels that excite electronic transitions. Absorption of UV-vis light excites molecules that are in ground-states to their excited-states. [5] Visible region 400–700 nm spectrophotometry is used extensively in colorimetry science. It is a known fact that it operates best at the range ...
The specificity of absorption spectra allows compounds to be distinguished from one another in a mixture, making absorption spectroscopy useful in wide variety of applications. For instance, Infrared gas analyzers can be used to identify the presence of pollutants in the air, distinguishing the pollutant from nitrogen, oxygen, water, and other ...