ANALYTICAL APPLICATIONS OF NUCLEAR REACTIONS

Activation analysis is an analytical technique that allows one to determine the amount of a given element X contained in some material Y. The basic steps in the activation technique are as follows  

Modem Nuclear Chemistry, by W.D. Loveland, D.J. Morrissey, and G.T. Seaborg Copyright 2006 John Wiley Sons, Inc. 

Irradiate Y with a source of ionizing radiation so that X will change into X, a radioactive isotope of X. 

Using chemical or instrumental techniques, isolate X and X from all other elements in Y (not necessarily quantitatively) and measure the activity of X. Chemical isolation of the activity of interest is performed simply by separating it chemically from all other activities. Instrumental isolation of the activity of interest involves the detection of radiation that can uniquely identify the nuclide in question. 

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In spite of the difficulties discussed above, the spectra of the cyclo-carbosilanes may be used in solving structural problems such as those associated with position isomerism in unsymmetrical methyl-substituted rings. This type of analytical application of nuclear magnetic resonance spectroscopy is particularly valuable for the carbosilanes, as the possibilities of establishing structures by chemical means are very restricted. The carbosilanes are not reactive and, unlike carbon compounds, undergo few reactions which yield information concerning their structures. In fact the structures of a number of compounds were first established with the aid of nuclear resonance. 

The application of nuclear reactions for analytical purposes started in parallel with the development of low-energy nuclear physics itself, and started to expand in the 1960s, which... 

Many artificial (likely radioactive) isotopes can be created through nuclear reactions. Radioactive isotopes of iodine are used in medicine, while isotopes of plutonium are used in making atomic bombs. In many analytical applications, the ratio of occurrence of the isotopes is important. For example, it may be important to know the exact ratio of the abundances (relative amounts) of the isotopes 1, 2, and 3 in hydrogen. Such knowledge can be obtained through a mass spectrometric measurement of the isotope abundance ratio. 

Contents Introduction. - Experimental Techniques Production of Energetic Atoms. Radiochemical Separation Techniques. Special Physical Techniques. - Characteristics of Hot Atom Reactions Gas Phase Hot Atom Reactions. Liquid Phase Hot Atom Reactions. Solid Phase Hot Atom Reactions. - Applications of Hot Atom Chemistry and Related Topics Applications in Inorganic, Analytical and Geochemistry. Applications in Physical Chemistry. Applications in Biochemistry and Nuclear Medicine. Hot Atom Chemistry in Energy-Related Research. Current Topics Related to Hot Atom Chemistry and Future Scope. - Subject Index. 

The most important applications of hydrogen sulfide involve the production of sodium sulfide and other inorganic sulfides. Hydrogen sulfide obtained as a by-product often is converted into sulfuric acid. It also is used in organic synthesis to make thiols or mercaptans. Other applications are in metallurgy for extracting nickel, copper, and cobalt as sulfides from their minerals and in classical qualitative analytical methods for precipitation of many metals (see Reactions). It also is used in producing heavy water for nuclear reactors. 

The operation, since 1945, of nuclear reactors has made available radioisotopes of most elements. The isotopes are useful in a variety of chemical investigations, including those concerned with solubility, diffusion, reaction mechanism and structure. They have given rise to new analytical techniques, such as isotopic dilution and radioactivation analysis. In industry also, they have a wide and rapidly expanding application. All this is made possible by the ease with which small quantities of the nuclides can be detected, often remotely, and quantitatively determined by commercially available and easily operated equipment. 

Since the pioneering studies reported by van Koten and coworkers in 1994 [20], dendrimers as catalyst supports have been attracting increasing attention. The metaUodendrimers and their catalytic applications have been frequently reported and reviewed [7-15]. As a novel type of soluble macromolecular support, dendrimers feature homogeneous reaction conditions (faster kinetics, accessibility of the metal site, and so on) and enable the application of common analytical techniques such as thin-layer chromatography (TLC) and nuclear magnetic resonance... 

NAA of Cr in biological materials is an excellent analytical method which offers a low bias and suitable sensitivity. It is, however, more time consuming than GFAAS and requires an elaborate infrastructure. Therefore its application is never oriented towards routine work, but focuses on research purposes. NAA is also often used as a reference method. The nuclear reaction involved is °Cr(n,y) Cr (ti/2= 27.7 d, y 320 keV, cross section o 15.8 barn isotopic abundance of °Cr 4.4 %). 

The section Radioactive Methods in volume 9 of the Treatise on Analytical Chemistry (Kolthoff and Elving 1971) discusses radioactive decay, radiation detection, tracer techniques, and activation analysis. It has a brief but informative chapter on radiochemical separations. A more recent text. Nuclear and Radiochemistry Fundamentals and Applications (Lieser 2001), discusses radioelements, decay, counting instruments, nuclear reactions, radioisotope production, and activation analysis in detail. It includes a brief chapter on the chemistry of radionuclides and a few pages on the properties of the actinides and transactinides. 

Abstract This chapter discusses the basic principles of analytical methods based on positive ion beams from particle accelerators. The methods, namely, particle-induced X-ray emission (PIXE), Rutherford backscattering spectroscopy (RBS), and nuclear reaction analysis (NRA) are described in detail. Besides the underlying physical processes, methodical questions, analytical capabilities, and typical fields of application are also discussed. 

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