An atomic absorption spectrometer is an analytical instrument used to determine the concentration of specific chemical elements, typically metals, in a sample by vaporizing the sample into a cloud of free atoms, usually through a flame or graphite furnace, and then measuring how much light of a wavelength characteristic of the target element is absorbed as it passes through that atomic vapor, with the absorption proportional to the element concentration. The technique was developed principally by the Australian physicist Alan Walsh in the 1950s, building on the long-known physical phenomenon of atomic absorption, and Walsh's instrument design established atomic absorption spectroscopy as a practical, reliable analytical method that was rapidly adopted by laboratories worldwide. Atomic absorption spectrometers remain widely used today for trace metal analysis in environmental and water quality testing, food and agricultural science, clinical and toxicological testing, and mining and metallurgy, valued for their sensitivity and specificity in measuring individual elements at very low concentrations.
Facts
Invented YearSourced to the subject's own account MeasuresSourced to the subject's own accountThe concentration of specific metals in a sample, determined from how much light of a characteristic wavelength the vaporized sample absorbs. 1 Operating PrincipleSourced to the subject's own accountMetal atoms in the sample are vaporized in a flame; each ground-state metal atom absorbs light at a wavelength unique to that element, and the absorbed radiation is proportional to atomic density. 1 ResolutionSourced to the subject's own accountHigh-resolution continuum-source instruments must resolve to about the half-width of an atomic absorption line, roughly 2 picometers, to avoid losing sensitivity. 1 Operating RangeSourced to the subject's own accountContinuum radiation sources used in AAS emit across roughly 190 to 900 nanometers. 1 Classification
Instrument ClassSourced to the subject's own account Connections
Used In
Atomic absorption spectrometry quantifies trace elemental concentration in a sample, a standard analytical chemistry technique since Alan Walsh's 1950s instrument.
Sources
1. Atomic Absorption Spectroscopy (Wikipedia)
WikipediaHistory section
Alan Walsh first described AAS in an article titled "The Application of Atomic Absorption Spectra to Chemical Analysis" published in 1955 by the journal Spectrachemica Acta.
Lead section, opening sentence
Atomic absorption spectroscopy (AAS) is an elemental analysis method for determining the concentration of metals in a given sample.
Lead section, second paragraph
The principle of AAS relies on the vaporization of metals within a sample when introduced to a flame.
Continuum Source AAS subsection
The resolution must be equal to or better than the half-width of an atomic absorption line (about 2 pm) in order to avoid loss of sensitivity and linearity of the calibration graph.
Continuum sources subsection
The lamp emits radiation of an intensity at least an order of magnitude above that of a typical HCL: wavelengths ranging from 190 nm to 900 nm.
Lede, instrument class
An atomic absorption spectrometer is an analytical instrument used to determine the concentration of specific chemical elements, typically metals, in a sample by vaporizing the sample into a cloud of free atoms, usually through a flame or graphite furnace, and then measuring how much light of a wavelength characteristic of the target element is absorbed as it passes through that atomic vapor, with the absorption proportional to the element concentration.
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