Atomic X-ray spectrometry

The section on Spectroscopy has been retained but with some revisions and expansion. The section includes ultraviolet-visible spectroscopy, fluorescence, infrared and Raman spectroscopy, and X-ray spectrometry. Detection limits are listed for the elements when using flame emission, flame atomic absorption, electrothermal atomic absorption, argon induction coupled plasma, and flame atomic fluorescence. Nuclear magnetic resonance embraces tables for the nuclear properties of the elements, proton chemical shifts and coupling constants, and similar material for carbon-13, boron-11, nitrogen-15, fluorine-19, silicon-19, and phosphoms-31. 

The characteristic X-ray wavelengths are tabulated in all standard texts on X-ray spectrometry, but can also be calculated from the atomic number of the element by Moseley s law ... 

For rapid analysis during the production process atomic absorption is mainly of indirect value because, due to the sequential character of the technique, it cannot be used for complete steel or slag analysis in a two to three minute period. The analytical requirements for the testing of rapid continuous production processes are fulfilled by the techniques of emission and X-ray spectrometry. These techniques are characterised by great speed, high precision and simultaneous multi-element analysis. Accuracy must, however, be constantly checked with a variety of special calibration samples. This requires the determination of the true concentrations of the calibration samples with chemical methods of solution analysis, whose precision is often only equal to or, when compared with X-ray spectrometry, frequently poorer. Chemical analysis is, however, the basis of all comparisons, and must be repeated frequently for the determination of the true concentrations. Atomic absorption, with its relatively good precision, has greatly simplified the analytical control of numerous elements. 

The Co particles were synthesized by the chemical deposition techniques from C0SO4 7 H2O solutions. The samples were characterized by TEM, X-Ray spectrometry and diffractometiy (DRON - SEIFERT-RM4). For investigation of nearest topological and chemical neighboring of Co atoms the NMR technique was used. The NMR spectra were measured by standard pulse spin-echo... 

Sulfur-containing components exist in gasoline-range hydrocarbons and can be identified with a gas chromatographic capillary colunm coupled with either a sulfur chemiluminescence detector or an atomic emission detector (AED) (ASTM D-5623). The most widely specified method for total sulfur content uses X-ray spectrometry (ASTM D-2622), and other methods that use ultraviolet fluorescence spectroscopy (ASTM D-5453) and/or hydrogenolysis and colorimetry (ASTM D-4045) are also apphcable, particularly when the sulfur level is low. 

In this chapter, we first present a theoretical discussion of the sources and properties of optical atomic spectra. We then list methods used for producing atoms from samples for elemental analysis. Finally, we describe in some detail the various techniques used for introducing samples into the devices that arc used for optical absorjHion, emis-, sion, and fluorescence spectrometry as well as atomic mass spectrometry. Chapter 9 is devoted to atormc.absorption methods, the most widely used of all the. atomic spectrometric techniques. Chapter 10 deals with several types of atomic emission techniques. Brief chapters on atomic mass spectrometry and atomic X-ray methods follow this discussion. 

Section 2 comprises seven chapters devoted to various aiomic speciromciric methods, including an introduction to spectroscopy and spectroscopic instrumentation. atomic absorption, atomic emission, atomic mass spcciR)inciry, and X-ray spectrometry. 

The chemical composition of most specimens has been checked where possible, using an analytical scanning electron microscope with energy-dispersive x-ray spectrometry facility. Elements with atomic number below that of fluorine are not detectable by this technique, e.g. boron, carbon and oxygen. Fluorine is only detectable when present in major amounts. Ratios quoted are semi-quantitative atomic ratios. Other elements are also listed where present at detectable levels. 

Figure 8.1 A schematic atom showing the steps leading to the emission of an X-ray photon (c) or an Auger electron (d), (From Jenkins, R. et al., Quantitative X-Ray Spectrometry, Marcel Dekker, Inc., New York, 1981. With permission.)...

Figure 8.4 Partial Moseley s law plots for selected K and L lines, showing the relationship between the X-ray emission wavelength and atomic number of the element. Using this relationship, it was possible to predict undiscovered elements and to correctly assign atomic numbers to known elements. (From Helsen, L.A. and Kuczumow, A., in Van Griekin, R.E. Markowicz, A. A. (eds.), Handbook of X-Ray Spectrometry, 2nd edn. Marcel Dekker, Inc. New York, 2002. Used with permission.)...

De Schrijver, I., Aramendia, M., Vineze, L., Resano, M., Dumouhn, A., Vanhaecke, F. (2007) Comparison of atomic absorption, mass and X-ray spectrometry techniques using... 

Table 11.11 The analysis of polymer digests by dibenzyidithiocarbamate precipitation - energy-dispersive x-ray spectrometry and electrothermal atomisation atomic absorption spectrometry ...

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