Radionuclide/radio isotopes

An inqx)rtant consideration in the use of radionuclides is their radiochemical purity since, should several radionuclides of different elements be present in a tracer sample used in an experiment, the result could be ambiguous and misleading. In a radio-chemically pure sample, all radioactivity comes from a single radioactive element. If the radioactivity comes from a single isotope, the sample may be said to be radio-isotopically pure. 

The best method to evaluate and to quantify obstruction is the radio-isotope study (diuretic radionuclide renogram). Two aspects of renal function are assessed renal clearance and excretion of the tracer. Estimation of relative clearance (differential renal function) requires the measurement of GFR by injection of chromium isotope-ethylnedi-amine-tetraacetic acid (Cr-EDTA) using a simple plasma sample technique. The most accurate method for evaluation of GFR is based on the plasma disappearance curve after a single bolus injection of a glomerular tracer. 

Ivanovich M., Blomqvist R., and Frape S. K. (1992) Rock/ water interaction study in deep crystalline rocks using isotopic and uranium series radionuclide techniques. Radio-himica Acta 58/59, 401-408. 

The long-lived uranium isotopes and are both chemotoxic and radio toxic (Fisher 1988, Metivier 1988), vhereas all other isotopes and decay products vith their much shorter half-lives are only critical due to the ionizing radiation emitted during their radioactive decay. This is the result of the inverse relationship between the specific radioactivity (Bqkg ) and the halflife of a radionuclide. 

We simply define radiochemistry and nuclear chemistry by the content of this book, which is primarily written for chemists. The content contains fimdamental chapters followed by those devoted to applications. Each chapter ends with a section of exercises (with answers) and literature references. An historic introduction (Ch. 1) leads to chapters on stable isotopes and isotope separation, on unstable isotopes and radioactivity, and on radionuclides in nature (Ch. 2-5). Nuclear radiation - emission, absorbance, chemical effects radiation chemistry), detection and uses - is covered in four chapters (Ch. 6-9). This is followed by several chapters on elementary particles, nuclear structure, nuclear reactions and the production of new atoms (radio-nuclides of known elements as well as the transuranium ones) in the laboratory and in cosmos (Ch. 10-17). Before the four final chapters on nuclear energy and its environmental effects (Ch. 19-22), we have inserted a chapter on radiation biology and radiation protection (Ch. 18). Chapter 18 thus ends the fimdam tal part of radiochemistry it is essential to all students who want to use radionuclides in scientific research. By this arrangement, the book is subdivided into 3 parts fundamental ladiochemistry, nuclear reactions, and applied nuclear energy. We hope that this shall satisfy teachers with differrat educational goals. 

The analytical application of radionuclides, along with other applications in radioanalysis, results directly from Hevesy and Paneth s invention of radio-tracer and radio-indication techniques in 1912. They pointed out that the addition to a solution of an element of its radioactive isotope makes possible the identification and determination of the element. In their first application they labeled a solution of lead with radium-D, a natural radioactive lead isotope and determined the solubility of sparingly soluble lead salts. 

Radionuclides in soil are a source of the contamination of forage and food with radionuclides, of which strontium, cesium, and radium isotopes are the most significant. Radionuclides penetrate into plants either from the atmosphere as deposits on soil surface or through roots from the soil. Plants radio-actively contaminated are a significant hazard to man, either directly (food of plant origin) or indirectly (the milk of animals which receive contaminated forage). 

Cl is activated to Cl, a long lived radio nuclide with a half life of 300 000 years. Most chlorides are soluble in water, which makes it more difficult to avoid long term release of Cl from a repository to the environment. In contrast, fluorides have low neutron cross sections and do not activate to radionuclides that create major challenges in waste management systems and form many insoluble waste forms. If a chloride salt was used, isotopically separated Cl would probably be required. 

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