Related Experiment Video
Updated: Feb 14, 2026
13:19
Enhanced Oil Recovery using a Combination of Biosurfactants
Published on: June 3, 2022
6.0K
DNP enhanced NMR with flip-back recovery
Snædís Björgvinsdóttir1, Brennan J Walder1, Arthur C Pinon1
1Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|February 8, 2018
Summary
The flip-back method enhances sensitivity in solid-state NMR (Nuclear Magnetic Resonance) experiments with long polarization build-up times. This technique improves signal detection and allows for shorter recycle delays, optimizing sensitivity in DNP-enhanced magic angle spinning NMR.
Area of Science:
- Solid-state Nuclear Magnetic Resonance (NMR) Spectroscopy
- Dynamic Nuclear Polarization (DNP) Enhanced Spectroscopy
- Magnetic Resonance Imaging (MRI) techniques
Background:
- Dynamic Nuclear Polarization (DNP) significantly enhances sensitivity in magic angle spinning solid-state NMR.
- Systems with long polarization build-up times necessitate lengthy recycling periods to optimize sensitivity.
- Optimizing sensitivity in DNP-enhanced solid-state NMR is crucial for analyzing complex biological and material systems.
Purpose of the Study:
- To investigate the efficacy of the classic flip-back method for improving sensitivity in DNP-enhanced solid-state NMR.
- To demonstrate the application of the flip-back method in systems with long polarization build-up times.
- To compare the sensitivity improvements offered by the flip-back method against modern heteronuclear decoupling techniques.
Main Methods:
- Implementation of the flip-back method to recover bulk proton magnetization after continuous wave proton heteronuclear decoupling.
- Experimental validation on diverse samples including BDPA radical doped o-terphenyl glass and microcrystalline theophylline, l-histidine, and salicylic acid.
- Acquisition of DNP-enhanced 2D refocused CP-INADEQUATE spectra utilizing the flip-back recovery technique.
Main Results:
- The flip-back method provides a simple yet effective means to improve sensitivity in DNP-enhanced solid-state NMR.
- Sensitivity enhancements achieved with the flip-back method surpass those from modern decoupling techniques like SPINAL-64.
- Optimal sensitivity was achieved at shorter recycle delays across various sample types.
- The flip-back recovery method proved particularly beneficial in rapid recycling regimes.
- Overhauser effect DNP enhancements exceeding 70 were observed at 592.6 GHz/900 MHz.
Conclusions:
- The flip-back method is a valuable technique for enhancing sensitivity in DNP-enhanced magic angle spinning solid-state NMR, especially for systems with long build-up times.
- This method offers a practical approach to achieve optimal sensitivity with reduced experimental time.
- The flip-back method represents a significant improvement over existing techniques, enabling more efficient data acquisition in advanced NMR studies.
More Related Videos
10:54Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
Published on: February 23, 2016
11.2K
09:37Preparation of Fungal and Plant Materials for Structural Elucidation Using Dynamic Nuclear Polarization Solid-State NMR
Published on: February 12, 2019
8.0K
Related Concept Videos
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
1.7K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.7K
01:04¹³C NMR: ¹H–¹³C Decoupling
1.9K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.9K
01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.7K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.7K
03:00Self-Evaluation: Self-Enhancement and Self-Verification
5.8K
Social psychologists have documented that feeling good about ourselves and maintaining positive self-esteem is a powerful motivator of human behavior (Tavris & Aronson, 2008). In the United States, members of the predominant culture typically think very highly of themselves and view themselves as good people who are above average on many desirable traits (Ehrlinger, Gilovich, & Ross, 2005). Often, our behavior, attitudes, and beliefs are affected when we experience a threat to our...
5.8K
01:24Muscle Recovery and Fatigue
4.3K
Muscle fatigue refers to the decline in a muscle's ability to maintain the force of contraction after prolonged activity. It primarily stems from changes within muscle fibers. Even before experiencing muscle fatigue, one may feel tired and have the urge to stop the activity. This response, known as central fatigue, occurs due to changes in the central nervous system, namely the brain and spinal cord. While there is no single mechanism that induces fatigue, it may serve as a protective...
4.3K
01:25Applications Of NMR In Biology
4.6K
Nuclear magnetic resonance (NMR) spectroscopy is a very valuable analytical technique for researchers. It has been used for more than 50 years as an analytical tool. F. Bloch and E. Purcell formulated NMR in 1946 and won the 1952 Nobel Prize in Physics for their work. Biological macromolecules such as proteins, nucleic acids, lipids, and organic molecules including pharmaceutical compounds, can be studied using this versatile tool that exploits the magnetic properties of certain nuclei.
4.6K