Radiochemistry applications

Radioactivity. Methods based on the measurement of radioactivity belong to the realm of radiochemistry and may involve measurement of the intensity of the radiation from a naturally radioactive material measurement of induced radioactivity arising from exposure of the sample under investigation to a neutron source (activation analysis) or the application of what is known as the isotope dilution technique. 

The successful application of microwave irradiation in chemistry dates from 1975 [2], Several examples have been described in analytical [3], environmental [3a, 4], and materials and inorganic chemistry [5], radiochemistry [6], and organometallic [7] and organic chemistry [8],... 

The application of the Chelex 100 resin separation and preconcentration, with the direct use of the resin itself as the final sample for analysis, is an extremely useful technique. The elements demonstrated to be analytically determinable from high salinity waters are cobalt, chromium, copper, iron, manganese, molybdenum, nickel, scandium, thorium, uranium, vanadium, and zinc. The determination of chromium and vanadium by this technique offers significant advantages over methods requiring aqueous final forms, in view of their poor elution reproducibility. The removal of sodium, chloride, and bromide allows the determination of elements with short and intermediate half-lives without radiochemistry, and greatly reduces the radiation dose received by personnel. This procedure was successfully applied in a study of... 

M.J. Welch, C.S. Redvanly, Handbook of Radiopharmaceuticals—Radiochemistry and Applications, Wiley, Chichester, (2003). 

It is clear that, along with the discovery of x-rays in 1895, Roentgen also found the chemical action of ionizing radiation. He drew attention to the similarity of the photographic effect induced by light and x-rays. Application to medicine appeared very quickly, followed by industrial applications. However, this field of investigation remained nameless until Milton Burton, in 1942, christened it radiation chemistry to separate it from radiochemistry which is the study of radioactive nuclei. Historical and classical work in radiation chemistry has been reviewed by Mozumder elsewhere [1]. Here we will only make a few brief remarks. 

Ehmann, W. D. and D. E. Vance. Radiochemistry and Nuclear Methods of Analysis, Wiley, New York, 1991. An up-to-date survey of nuclear chemistry that emphasizes its applications in analytical chemistry. 

Choppin, G. R., J. O. Liljenzin, and J. Rydberg. Radiochemistry and Nuclear Chemistry, 3rd ed., Butterworth-Heineman, Oxford, 2001. A very good, broad discussion of nuclear chemistry that is oriented toward nuclear power and nuclear power applications. 

Keller, C. Radiochemistry, Harwood, 1981. A very condensed presentation of radioactivity and its applications. 

One of the most important applications of nuclear and radiochemistry is in the area of nuclear power. Chemistry and chemical processes are intimately involved in reactor operation, the preparation and processing of reactor fuel, and the storage and ultimate disposal of radioactive waste. In this chapter, we shall examine some of the most important chemistry associated with nuclear power. 

Lieser, K. H. Nuclear and Radiochemistry Fundamentals and Applications, VCH, New York, 1997. Covers a number of the practical aspects of the subject that are important to radiochemists. 

Radiochemistry is defined as the chemical study of radioactive elements, both natural and artificial, and their use in the study of chemical processes (Random House Dictionary, 1984). Operationally, radiochemistry is defined by the activities of radiochemists, that is, (a) nuclear analytical methods, (b) the application of radionuclides in areas outside of chemistry, such as medicine, (c) the physics and chemistry of the radioelements, (d) the physics and chemistry of high-activity-level matter, and (e) radiotracer studies. We have dealt with several of these topics in Chapters 4, 13, 15, and 16. In this chapter, we will discuss the basic principles behind radiochemical techniques and some details of their application. 

Radiochemistry involves the application of the basic ideas of inorganic, organic, physical, and analytical chemistry to the manipulation of radioactive material. However, the need to manipulate radioactive materials imposes some special constraints (and features) upon these endeavors. The first of these features is the number of atoms involved and the solution concentrations. The range of activity levels in radiochemical procedures ranges from pCi to MCi. For the sake of discussion, let us assume an activity level, D, typical of radiotracer experiments of 1 p,Ci (= 3.7 x 104 dis/s = 3.7 x 104 Bq), of a nucleus with mass number A 100. If we assume a half-life for this radionuclide of 3 d, the number of nuclei present can be calculated from the equation... 

Lieser, K. Nuclear and Radiochemistry Fundamentals and Applications, VCH, New York, 1997. 

Special properties of radioactive nuclides (isotopes of an element, Chapter 2) make them useful tracers for following complex processes. Radiochemistry is the branch of chemistry which involves the applications of radioactivity to chemical problems, as well as the chemical processing of radioactive substances. 

The NAA method for the determination of firearm discharge residue has been generally accepted, but applications have been limited to just a few laboratories. In the process of establishing NAA capability for the State of Illinois crime laboratories we re-examined the standard techniques (10). In the course of our work it became clear that post-irradiation is the cause of several constraints which have discouraged a more widespread use of NAA. The inherent time limitation due to the 87 min. half-life of 139Ba necessitates fast manipulations of radioactive solutions which in turn requires an experienced radiochemist. In addition to an ever present danger of overexposure and contamination, typically only a dozen samples can be irradiated per batch, which makes the method quite expensive. The developed statistical bivariate-normal analysis (11) is convenient for routine applications. With this in mind, a method was developed which a) eliminates post-irradiation radiochemistry and thus maximizes time for analysis b) accommodates over 130 samples per irradiation capsule (rabbit) c) does not require a collection of occupational handblanks and d) utilizes a simplified statistical concept based on natural antimony and barium levels on hands for the interpretation of data. The detailed procedure will be published elsewhere (15). 

The experiments in this manual were selected to accompany the textbookRadio-analytical Chemistry. The manual is intended to acquaint the senior or graduate student with the practices of radioanalytical chemistry and develop some familiarity with the various techniques and methods commonly used in the radioanalytical laboratory and the counting room. The authors believe that only hands-on experience can translate the guidance provided by a textbook to an understanding of the applications that form the basis of this aspect of radiochemistry. 

For technical applications, knowledge of the irradiation behaviour of the Levextrel-TBP resin is important. A detailed study carried out at the Radiochemistry Institute of the Technical University, Munich(21,22), showed that with gamma irradiation the formation rate of dibutyl phosphoric acid (HDBP) and of "non-removable" acidic radiolysis products ("do-bads") is 2 to 5 times lower with Levextrel-TBP resin than with pure TBP the effect is attributed to the "scavanger" action of the aromatic groups in the matrix material. In summary, a high radiation resistance of the resin has become evident. 

Refs. [i] Habashi F (ed) (1998) Alloys, preparation, properties, applications. Wiley-VCH, Weinheim [ii] Matucha KH (1996) Structure and properties of nonferrous alloys. In Matucha KH (ed) Materials science and technology. A comprehensive treatment, vol 8. VCH, Weinheim [iii] Fleischer A, Lander J, (eds) (1971) Zinc-silver oxide batteries. Wiley, Chichester [iv] Hicks HG (1960) The radiochemistry of zinc. McGraw-Hill, New York [v] Linden D, Thomas BR (eds) (2002) Handbook of batteries, 3rd edn McGraw-Hill, New York [vi] Pauling L (1970) General chemistry, 3rd edn. Freeman, San Francisco [vii] Lide DR (ed) (2003-2004) Handbook of chemistry and physics, 84th edn. CRC Press, Boca Raton [viii] http //periodic.lanl.gov/elements/30.html... 

This volume which deals with rapid radiochemical separations Is the fourth In a series of monographs on radiochemical techniques which will parallel the series on the radiochemistry of the elements. The same general style Is used in both series of monographs, Including general reviews of the technique, discussions of the principles involved, a detailed survey of applications to different systems, and a collection of selected procedures which use this technique as reported in the literature. 

J. A. Katzenellenbogen, in Handbook of Radiopharmaceuticals Radiochemistry and Applications , eds. M. J. Welch and C. S. Redvanly, John Wiley and Sons, West Sussex, 2003. 

J. I. Vargas, The Chemical Applications of Angular Correlation and Half-life Measurements, in Radiochemistry, International Review of Sciences, Inorganic Chemistry, Series One, Vol. 8 (Ed. A. G. Maddock), Butterworths, London, 1971... 

An important application of isotope dilution in radiochemistry is the determination of a radionuclide by dilution with an inactive nuclide (inactive compound), also called reverse isotope dilution. This apphcation is very valuable if the radionuclide is present in carrier-free form. Again, quantitative separation is avoided a measured amount mi of an inactive isotope of the element to be determined is added and after a non-quantitative separation the amount m2 is measured. The ratio wa/wi is the yield of the separation procedure and the activity of the carrier-free radionuclide (Ax = 0) is obtained from the measured activity A2 ... 

International Atomic Energy Agency, Exchange Reactions, IAEA, Vienna, 1965 H. A. C. McKay, Physicochemical Applications of Radiotracers, in Principles of Radiochemistry, Butterworths, London, 1971... 

Nowadays, nuclear medicine has become an indispensible section of medical science, and the production of radionuclides and labelled compounds for application in nuclear medicine is an important branch of nuclear and radiochemistry. The development of radionuclide generators made short-lived radionuclides available at any time for medical application. New imaging devices, such as single photon emission tomography (SPET) and positron emission tomography (PET) made it possible to study local biochemical reactions and their kinetics in the living human body. 

R. M. Lambrecht, N. A. Morcos (Eds.), Applications of Nuclear and Radiochemistry, Part I, Radiopharmaceutical Chemistry, Pergamon, Oxford, 1982... 

J. A. Heslop, Industrial Applications of Radioisotopes, in Radiochemistry, Vol. 3, Specialist Periodical Reports, The Chemical Society, London, 1976... 

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