Nuclear magnetic resonance (NMR) is an analytical tool used to study the structure and dynamics of molecules by chemists and physicists. NMR spectroscopy is the study of molecules by recording the interaction of radiofrequency (Rf) electromagnetic radiations with the nuclei of molecules placed in a strong magnetic field. NMR Spectroscopy, like all other spectroscopic techniques, involves the material being examined with electromagnetic radiation interaction.
In science the term spectroscopy has come to mean the separation or classification of various items into groups; for example the separation of the various isotopes of the chemical element is called Mass Spectrometry. Spectroscopy is the study of matter using electromagnetic radiation.
Basic Principle of NMR Spectroscopy
The fundamental property of the atomic nucleus involved in NMR is the nuclear spin. The value of spin depends on the mass number and the atomic number of the nucleus. To understand NMR spectroscopy principles, it is necessary to know how the nuclear energy states are generated and what the energy and population associated with the energy states are. Not any kind of nucleus will give NMR signals.
- Relaxation in nuclear magnetic resonance spectroscopy (NMR) is a fundamental phenomenon that affects both line shapes and NMR signal intensities.
- It provides information on molecular structure and dynamics. Comprehension of these aspects therefore lays the foundation for understanding the basic principles of NMR spectroscopy.
- Nuclei with an even number of both charge and mass have a spin quantum number of zero, for example 12C.
- These kinds of nuclei do not have nuclear angular momentum and will not give rise to an NMR signal. These are called NMR inactive nuclei.
Applications of Mass Spectrometry
Mass spectrometry has found many applications in the analysis and quantitation of small to large molecular weight compounds in areas of energy, environment, forensics, space exploration and in clinical and biological laboratories. A list of applications in the analysis of microorganisms has proven to be accurate and a cost effective approach in clinical settings.
Traditionally mass spectrometers for clinical applications were found in specialty or reference laboratories with experts in particular areas of medicine. More recently, public health labs and larger commercial labs have begun utilizing mass spectrometry.
Determination and information of structure of an unknown compound is obtained from various spectroscopic techniques, which are then used to assemble a proposed structure, which then goes through a rigorous process. Finally the structure must agree with all the spectral observations.