CNS analyzer for the determination of total carbon, nitrogen, and sulfur

The sample is weighed into a tin container and moved to the combustion chamber at l,020°C. Combustion of the tin container causes a powerful reaction in an atmosphere of enriched oxygen, completely oxidizing the sample. The combustion products ((X), 

The ratio of carbon to nitrogen in a sample is used as a measure of the quality of preservation in bone and a means to determine if samples are reliable for the analysis of collagen for radiocarbon dating and dietary analysis using light isotopes. The ratio of C N in living bone is 3.2 a ratio between 2.8 and 3.5 has been suggested as indicative of fossil bone sufficiently well preserved for analysis. 

One of the more widely used techniques of the last 50 years has been NAA, sometimes defined as instrumental neutron activation analysis (INAA). NAA uses gamma-rays, the highest energy end of the spectrum, to measure a wide variety of elements to parts-per-million concentrations. At the same time, NAA requires a nuclear reactor - not readily available to many researchers. 

NAA is gamma ray spectroscopy that uses the slow thermal neutrons from a nuclear reactor to excite the nucleus of an atom. When an atom absorbs a thermal neutron, its atomic mass increases by one and the nucleus becomes unstable. One or more nuclear reactions then take place that release gamma-rays with energies characteristic of the particular nuclear decay reactions, along with other radiation (Fig. 4.14). While 

The Scottish chemist Frederick Soddy first used the term isotope to describe his observation than atoms with different atomic masses have the same chemical properties and occupy the same position in the periodic table. Today we understand that the number of protons in the atomic nucleus defines the chemical properties and the identity of an element, but there can be different numbers of neutrons associated with the same number of protons, resulting in the same element having several possible masses, or isotopes. 

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