Page 41 - Academic Press Encyclopedia of Physical Science and Technology 3rd Analytical Chemistry

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Encyclopedia of Physical Science and Technology en001d42 May 26, 2001 14:55

Atomic Spectrometry

Vahid Majidi
Chemistry Division, Los Alamos National Laboratory

I. Atomic Spectrometric Techniques
II. Optical Detection
III. Atomic Emission Spectrometry
IV. Atomic Absorption Spectrometry
V. Atomic Fluorescence Spectrometry
VI. Detection of Elemental Ions
VII. Comparisons of the Atomic
Spectrometric Techniques

GLOSSARY Standard Sample that contains the analyte at a known
concentration from which a signal can be obtained that
Analyte Element whose concentration is to be deter- can be compared with the signal from a sample of un-
mined in a matrix. known analyte concentration. From this, the concen-
Atom cell Device that provides a sufficiently high tem- tration of the analyte in the unknown sample can be
perature to break down the sample into its constituent determined.
atoms.
Differential pumping Evacuating two chambers, ad-
joined by a conductance limited orifice, with the use ATOMIC SPECTROMETRY is a series of analytical
of either one or two independent vacuum pumps. This techniques that are used to determine the identity and
allows for maintaining two connected chambers at dif- concentration of elements in any sample. While his-
ferent pressures with respect to one another. torically the detection of analytical signals was exclu-
Interference Increase or decrease in the size of the signal sively done through measurement of photons, during
obtained from the analyte as a result of the presence the past two decades atomic spectroscopists have suc-
of some other known or unknown component in the cessfully integrated the measurement of ion current into
matrix. the suite of detection technologies known as atomic
Matrix Components of a sample other than the element spectrometry. Photon-detection-based techniques include
whose concentration is to be determined. atomic emission, atomic absorption, and atomic fluores-
Multi-element Multi-element analysis is the simultane- cence spectrometry. Ion-detection technologies include
ous or rapid sequential determination of the concentra- laser-enhanced ionization and elemental mass spectrom-
tion of several elements in a matrix. etry (MS). Absolute analyte masses at the nanogram

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