Chemical Aspects of Atomic Absorption

Abstract

The phenomenal growth of atomic absorption spectrometry in the past twelve years can be attributed to many factors such as the high sensitivity of the method for a large number of elements, advances in overcoming interferences, saving of time required for analysis, and the rapid improvement of instrumentation. The major interferences in atomic absorption are of a chemical nature; however, physical interferences which are associated with the chemical matrix often are present. To overcome chemical interferences and to eliminate or minimize their influences from phosphate, aluminum, titanium, and any other elements producing nonvolatile compounds, releasing agents, or high-temperature flames are used. Also, the use of a separation and preconcentration technique often becomes necessary when determining elements at the subtrace level. A list of organic ligands and solvents used in solvent extraction for absorption is presented as a means of preconcentration and removal of chemical interferences.

Direct determination of barium in sea and estuarine water by graphite furnace atomic spectrometry

“…Either a two-point bracketing procedure or a linear regression fit to a multipoint calibration curve was used, depending on the linearity of the calibration curve. All samples were spiked and a one-point standard addition procedure was used to correct for interferences (23). The sample size was 20 p L .…”

Analytical coordination chemistry section:

“…This is shown in figure 2B. While the first derivative has been used in spectroscopy [3] for identifying overlapping band structures, scanning of the wavelength region is required. This offers no advantage in flame emission over the mechanical disc chopper.…”

“…In the pH range of 2-3 the reduction is both acid-catalyzed and light-catalyzed (figure 8). At the end of this period a portion of one was placed into the spectrophotometer and repeated absorbances were measured over a [2][3][4][5][6] minute time interval. During this time the sample was in the light path only long enough to obtain a measurement.…”

“…Results and Discussion . Dyrssen [23] has pointed out that the Pe-IPT complex takes [1][2][3][4] days to reach equilibrium.…”

“…In a related study, 3 Consequently, greater emphasis should now be placed on the development of additive and reproducible color systems and less concern should be given to the complexity cf the spectra involved.…”