13C NMR spectroscopy and application of carbon isotopes


Application of carbon isotopes


Carbon element isotopes have various applications in physics, chemistry, biology, medicine, archaeology, oil and gas, etc.


Carbon isotope applications 13


The most important applications of the carbon-13 isotope are in medicine and in the diagnosis of metabolic diseases such as oncology, as well as in determining the structure of organic matter.


Applications in physics


Carbon-13 isotope is widely used in physics and biophysics to study nuclear reactions.

It is used to measure nuclear concentrations and to study the inelastic scattering of polarized protons, and in particular to study the mechanism of processes that take place in living organisms.


Applications in Chemistry


The carbon-13 isotope is widely used as a marker to identify the structure of organic compounds and even biological structures without damaging or degrading them. This has provided a strong impetus for achieving effective methods for isolating this stable isotope as well as expanding its various forms of nuclear magnetic resonance spectroscopy (CNMR). The study of carbon nuclei by nuclear magnetic resonance spectroscopy (CNMR) is an important technique for determining the structure of organic molecules. Completely identify the unknown composition.


Carbon-12, the most abundant carbon isotope, is inactive in the CNMR technique because it has zero spin. But carbon-13, due to its mass number, also has a nuclear spin and can be used in this technique. With the new Fourier transform FT-NMR, it is possible to obtain more accurate and faster organic and proton spectra of organic compounds, although carbon signals are slightly more difficult to detect than proton spectra. 13 can be used to determine the number of unbalanced carbons as well as to identify the types of carbons (methyl, methylene, aromatic, carbonyl, etc.) present in a compound and to directly obtain information about the carbon skeleton of a molecule. Thus, determining the structure of a compound using CNMR is simpler than HNMR, although both techniques are used to determine the structure of an unknown compound, and both are complementary.


Applications in medicine


Other applications of the carbon-13 isotope include the diagnosis of disability and organ failure in living organisms, the most important of which are the diagnosis of liver, lung and pancreas (diabetes) and heart muscle weakness. Also in diseases related to metabolic defects such as cancers, due to abnormal function of endocrine glands and other organs of the body, to diagnose these deficiencies of carbon-13 labelled compounds such as metabolites and lactates in nuclear resonance spectroscopy (MRS) And nuclear resonance spectroscopy (MRSI) is used. Based on NMR and MRI techniques, this technique examines the changes in metabolites in the study area.


Nuclear resonance spectroscopy


NMR is a very powerful and versatile analysis tool for solving a wide range of biochemical problems. So that today has a special place in metabolic studies. In fact, metabolomics includes the scientific study of chemical processes related to metabolites, small molecular intermediates, products of metabolism, and the study of the profile of small molecular metabolites resulting from biochemical processes. Metabolic profiles can provide a snapshot of the physiology of the cell under study. Although various mass spectrometry techniques have often been used for metabolic studies, the unique capabilities of the NMR technique have provided many valuable advantages in this scientific field. These benefits include:


• Analysis of the exact position of isotopomers in metabolites with isotopic enrichment


Determining the structure of unknown metabolites


• Accurate measurements without the need for standards


Dynamic analysis of metabolic pathways from cells to organs

. • Research on enriched stable isotope detectors to detect biochemical pathways and networks

Simply put, the stable carbon-13 isotope is used to diagnose different types of disease. This isotope is injected into the patient's body in the form of a sugar molecule. The patient's body is then imaged by the nuclear magnetic resonance (MRS) technique. By dividing the suspected area into different three-dimensional pixels and examining the metabolic and lactate changes of these voxels, the progression of the cancerous mass is determined.


Application in oil and gas


One of the major applications of the stable carbon-13 isotope in identifying the source and origin of the existing hydrocarbon sources of oil reservoirs is by using their fingerprints or isotopic signatures. Because oil inherits the isotopic and molecular properties of its parent kerogen, modern isotopic analyzes performed at the molecular level make it possible to identify different oil sources by determining the correlation between oil and reservoir rock. The failure of chemical bonds to produce natural gas, ie C1 to C4 hydrocarbons from oil or kerogen, leads to thermal isotopic subtraction and prevents the resulting gases from inheriting the isotopic and molecular properties of their parent. This isotopic subtraction is the result of different kinetics of isotopes 13c, 12c, D, H, 14N, 15N, 32S, 34S

It is in the process of breaking and creating new bonds, which eventually leads to the enrichment of 12C in methane and lighter products, and of course 13C in heavier products. In other words, the application of stable carbon-13 isotope in the oil industry can be summarized as follows.


Application of carbon-14 isotope


The life of old objects is determined by the radioactive isotope carbon-14, which changes naturally. With the help of carbon-14 timing, it is possible to determine the lifespan of objects up to 60,000 years. The amount of this isotope in the body of living organisms is constant due to their nutrition from hydrocarbon sources. With the death of these organisms and the lack of this isotope from external sources and due to its decay, the amount of carbon-14 isotope in the bodies and their remaining organs is gradually reduced. Due to the half-life of five thousand and seven hundred years of this isotope, after every 5700 years, half of it borrows and in this decay, carbon-14 is converted to N by emitting a beta particle B or electron e, and this process Will continue. By determining how much of the radioactive nucleus remains, it can be seen how many half-lives of the material have elapsed, and by knowing the half-lives of the elements, one can easily calculate the age of old objects.


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