Atomic Absorption Spectroscopy - Analytical Chemistry (ACS

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Anal. Chem. 1960.32:17A-29A. Downloaded from pubs.acs.org by UNIV OF TEXAS SW MEDICAL CTR on 10/13/18. For personal use only.

Atomic Absorption Spectroscopy J. W. Robinson,

Esso Research

Laboratories, Baton Rouge, Louisiana

Introduction The determination of trace metal impurities has always provided a challenge to the analytical chemist. With progress in industrial technology and in all the disciplines of science, this problem becomes increasingly important. Considerable technical effort has been spent on improving well known instrumental techniques—spectrography, polar-

ography, ionophoresis—and improving chemical methods, e.g., by solvent extraction, organic reagents.

As most of these processes

already well known, a major breakthrough in this field of analytical work will probably come

are

about only by the development of Atomic absorpa new technique. tion spectroscopy seems to be such a technique. As far back as 1955, A. Walsh and his coworkers pointed out that the phenomenon responsible for Fraunhoffer lines could be utilized for trace metal analysis. His experiments showed that only comparatively simple equipment was required for the detection and determination of several metals at the parts per million level of concentration. Since that time, further pioneering work on his part has established this as a scientific field of major importance, potentially capable of solving composition

equilibrium and kinetic problems in branches of science. It seems possible that with the devel-

many

opment of commercial equipment for this work, its value will be fully realized.

Principle The analytical

application is the fact that metal atoms absorb strongly at discrete, characteristic wave lengths, which coincide with the emission spectra lines of the particular metal. A simple presentation of the process is shown in Figure 1 (page 19 A). The process for emitting spectra, as in flame photometry and emission spectrography, is the reverse based

on

VOL. 32, NO. a, JULY 1960

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