Dating methods, radiochemical

The discovery that ordinary carbon is composed of three isotopes was made by William Giauque in 1929. Carbon-14 was isolated in 1940, and by 1945 Willard Libby had formulated the carbon-14 dating method, still the most commonly known radiochemical chronometric (time-measuring) method. As represented in... 

Neutrino detectors are placed at great depths, at the bottom of mines and tunnels, in order to reduce interference induced by cosmic rays (Fig. 5.3). Two methods of detection have been used to date. The first is radiochemical. It involves the production by transmutation of a radioactive isotope that is easily detectable even in minute quantities. More precisely, the idea is that a certain element is transformed into another by a neutrino impact, should it occur. Inside the target nucleus, the elementary reaction is... 

Tracer methods — [i] The application of radiotracer methods in electrochemistry dates back to the pioneering works by Hevesy in 1914. The aim of these studies was to demonstrate that isotopic elements can replace each other in both -> electrodeposition and equilibrium processes (Nernst law -> Nernst equation). Nevertheless, Joliot s fundamental work in 1930 is considered by electrochemists as a landmark in the application of -> radiochemical (nuclear) methods in electrochemistry. 

Some relevant terms for activation analysis are activation analysis, neutron activation analysis (NAA), instrumental neutron activation analysis (INAA), neutron activation analysis with radiochemical separation (RNAA), photon activation, neutron capture prompt gamma activation analysis (PGAA), charged particle activation, autoradiography, liquid scintillation counting, nuclear microprobe analysis, radiocarbon (and other element) dating, radioimmunoassay, nuclear track technique, other nuclear and radiochemical methods. Briefly, the salient features of some of the more popular techniques are as follows ... 

The final area to be discussed here involves the study of thermal ion reactions by recoil methods. This represents one of the newest applications reported and potentially one of the most exciting. Studies to date are unique in that they incorporate a combination of radiochemical detection that allows investigation of submicroscopic ion concentrations and recoil energetics that often ensures escape from solvation. Thus, isolated ions can be studied in the liquid phase without the complications of ion pairing or solvation, and truly thermal processes involving gas phase ions that are diflBcult at best to observe in chemical accelerators due to space change limits can be investigated. 

See also Archaeometry and Antique Analysis Dating of Artifacts. Bioassays Ovenriew. Drug Metabolism Metabolite Isolation and Identification Isotope Studies. Fertilizers. Food and Nutritional Analysis Meat and Meat Products. Immunoassays, Techniques Radioimmunoassays. Isotope Dilution Analysis. Pesticides. Pharmaceutical Analysis Drug Purity Determination. Process Analysis Overview. Radiochemical Methods Pharmaceutical Applications. Water Analysis Industrial Effluents. 

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