Measurement Techniques For Tritium And Carbon 14

Tritium and radiocarbon are pure beta emitters. Tritium has an average energy of 5.7 keV and endpoint energy of 18.6 keV [1]. Radiocarbon has an average energy of 49.5 keV and endpoint energy of 156 keV. The half-life of tritium and radiocarbon is 12.3 years and 5730 years, respectively. Hydrogen has three isotopes, namely hydrogen (1H), deuterium (2H), and tritium (3H). Among the three isotopes, tritium alone is a radioactive isotope. The natural abundance of hydrogen, deuterium, and tritium are 99.985%, 0.015%, and 1x10-18%. Carbon is also having three isotopes 12C, 13C, and 14C. The isotopes 12C and 13C are stable, whereas 14C is radioactive. The natural abundance of 12C, 13C and 14C are approximately 98.89%%, 1.11% and 1.2 x 10-10% respectively. Tritium is continuously produced in the atmosphere with cosmic-ray induced neutron activation of atmospheric gases. The reaction occurs with fast neutrons. The threshold neutron energy for the 14N (1n, 3H) 12C is 4 MeV [1].

"As a consequence of the increasing importance of tritium resulting from nuclear fission and neutron activation, from its use in accelerators, from its use in research and industry, and from its use in the investigation of the environment and its distribution in the environment, the NCRP designated a scientific committee to prepare a report on the currently acceptable methods of measuring tritium. This report is particularly aimed in assisting an individual to select a procedure suitable to the problem at hand." --From Preface, page iii.

Compounds labeled with carbon-14 and tritium are indispensable tools for research in biomedical sciences, discovery and development of pharmaceuticals and agrochemicals. Preparation of Compounds Labeled with Tritium and Carbon-14 is a comprehensive, authoritative and up-to-date discussion of the strategies, synthetic approaches, reactions techniques, and resources for the preparation of compounds labeled with either of these isotopes. A large number of examples are presented for the use of isotopic sources and building blocks in the preparation of labeled target compounds, illustrating the range of possibilities for embedding isotopic labels in selected moieties of complex structures. Topics include: Formulation of synthetic strategies for preparing labeled compounds Isotope exchange methods and synthetic alternatives for preparing tritiated compounds In-depth discussion of carbon-14 building blocks and their utility in synthesis Preparation of enantiomerically pure isotopically labeled compounds Applications of biotransformations Preparation of Compounds Labeled with Tritium and Carbon-14 is an essential guide to the specialist strategies and tactics used by chemists to prepare compounds tagged with theradioactive atoms carbon-14 and tritium.

This book focuses on tritium as a fuel for fusion reactors and a next-generation energy source. Following an introduction of tritium as a hydrogen radioisotope, important issues involved in establishing safe and economical tritium fuel cycles including breeding for a fusion reactor are summarized; these include the handling of large amounts of tritium: confinement, leakage, contamination, permeation, regulation and tritium accountancy, and impacts on surrounding areas. Targeting and encouraging the students and technicians who will design and operate fusion reactors in the near future, this book offers a valuable resource on tritium science and technology.

Newer Methods of Nutritional Biochemistry: With Applications and Interpretations, Volume III presents the pressing problems in emergency feeding of populations in developing areas of the world with emphasis on the need for simple procedures to assess utilization of dietary proteins. This book reviews the criterion of protein utilization and considers the important components of protein metabolism. Organized into 11 chapters, this volume starts with an overview of the metabolic changes induced by deficiencies of essential nutrients. This text then examines the problems of human protein needs in the light of the food habits of vegetarians. Other chapters explore lipid metabolism in terms of its dynamic mechanisms. This book discusses as well the significance of minerals in the utilization of primary foodstuffs, namely, carbohydrates, proteins, and fats. The final chapter deals with the methodology for studies in human nutrition. This book is a valuable resource for biochemists, graduate students, and clinical researchers.