Gradient enhanced NMR spectroscopy
- Gradient enhanced NMR spectroscopy
Gradient enhanced NMR is a method for obtaining high resolution nuclear magnetic resonance spectra without the need for "phase cycling". Gradient methodology is used extensively for two purposes, either rephasing (selection) or dephasing (elimination) of a particular magnetization transfer pathway. It includes the application of magnetic field gradient pulses to select specific coherences. By using actively shielded gradients, a gradient pulse is applied during the evolution period of the selected coherence to dephase the transverse magnetization and another gradient pulse refocuses the desired coherences remaining during the acquisition period.
Advantages
*Significant reduction in measuring time
*Reduced T1 artifacts
*Elimination of phase cycling and difference methods
*Possibility for three and four-quantum editing
*The ability to detect resonances at the same chemical shift as a strong solvent resonance
Drawbacks
*A need for field-frequency-lock blanking during long runs.
Examples
*Selection of transverse magnetization (Ix, Sx, Iy etc.): (+)gradient 180°(x) (+)gradient
*Suppression of transverse magnetization (Ix, Sx, Iy etc.): (+)gradient 180°(x) (-)gradient
References
*Ralpg E. Hurd, Gradient-Enhanced Spectroscopy, Journal of magnetic resonance. 87, 422-428 (1990)
Wikimedia Foundation.
2010.
Look at other dictionaries:
Pulsed field gradient — A Pulsed field gradient is a short, timed pulse with spatial dependent field intensity. Any gradient is identified by four characteristics: axis, strength, shape and duration. Pulsed field gradient (PFG) techniques are key to magnetic resonance… … Wikipedia
Nuclear magnetic resonance spectroscopy of carbohydrates — Carbohydrate NMR Spectroscopy is the application of nuclear magnetic resonance (NMR) spectroscopy to structural and conformational analysis of carbohydrates. This tool allows the carbohydrate chemist to determine the structure of monosaccharides… … Wikipedia
Mössbauer spectroscopy — A Mössbauer absorption spectrum of 57Fe Mössbauer spectroscopy is a spectroscopic technique based on the Mössbauer effect. This effect, discovered by Rudolf Mössbauer in 1957, consists in the recoil free, resonant absorption and emission of gamma … Wikipedia
Rotational spectroscopy — Part of the rotational vibrational spectrum of carbon monoxide (CO) gas (from FTIR), showing the presence of P and R branches. Frequency is on the x axis, and absorbance on the y axis. Rotational spectroscopy or microwave spectroscopy studies the … Wikipedia
Solid-state nuclear magnetic resonance — (NMR) spectroscopy, characterized by the presence of anisotropic (directionally dependent) interactions.IntroductionBasic conceptsA spin interacts with a magnetic or an electric field. Spatial proximity and/or a chemical bond between two atoms… … Wikipedia
Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… … Universalium
Nuclear magnetic resonance — This article is about the physical phenomenon. For its use as a method in spectroscopy, see Nuclear magnetic resonance spectroscopy. NMR redirects here. For other uses, see NMR (disambiguation). First 1 GHz NMR Spectrometer (1000 MHz,… … Wikipedia
Nuclear Overhauser effect — The Nuclear Overhauser Effect (NOE) is the transfer of nuclear spin polarization from one nuclear spin population to another via cross relaxation. It is a common phenomenon observed by nuclear magnetic resonance (NMR) spectroscopy. The… … Wikipedia
Physical Sciences — ▪ 2009 Introduction Scientists discovered a new family of superconducting materials and obtained unique images of individual hydrogen atoms and of a multiple exoplanet system. Europe completed the Large Hadron Collider, and China and India took… … Universalium
Model lipid bilayer — A model lipid bilayer is any bilayer assembled in vitro, as opposed to the bilayer of natural cell membranes or covering various sub cellular structures like the nucleus. A model bilayer can be made with either synthetic or natural lipids. The… … Wikipedia
