Feb 17, 2025
Version 1
Quadrupolar Non-Quantitative Bloch Decay V.1
This protocol is a draft, published without a DOI.
- Alexander L. Paterson1
- 1National Magnetic Resonance Facility at Madison (NMRFAM), University of Wisconsin-Madison, Madison, WI, United States
Protocol Citation: Alexander L. Paterson 2025. Quadrupolar Non-Quantitative Bloch Decay. protocols.io https://protocols.io/view/quadrupolar-non-quantitative-bloch-decay-dzut76wnVersion created by NMRFAM Facility
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: In development
We are still developing and optimizing this protocol, but it should be functional. We hope to solicit feedback primarily on clarity and usability. We intend to publish it in June 2025.
Created: January 21, 2025
Last Modified: February 17, 2025
Protocol Integer ID: 120435
Keywords: Non-Quantitative MAS Bloch Decay: 23Na
Funders Acknowledgements:
National Science Foundation
Grant ID: 1946970
Abstract
Purpose
To acquire a 1D MAS spectrum on a quadrupolar nucleus, optimized for sensitivity with non-quantitative intensities.
Scope
The acquisition of 1D NMR spectra of quadrupolar nuclei with non-quantitative intensities allows for greater sensitivity per unit time than acquisition with quantitative intensities. This SOP should be followed when quantitative intensities are not required. If quantitative intensities are required do not use this protocol.
Materials
Definitions:
- CT: Central Transition
Appendix:
Using the tip angles above will result in the maximum sensitivity for resonances within the CT-selective limit with non-zero intensity for the non-selective limit. These angles should ensure that all resonances are observed, but they will not be homogeneously excited and relative intensities will not be reliable.
Before start
User should be familiar with the power limitations and duty cycle of the probe being used.
User should be familiar with the maximum safe spinning speed of the probe and rotor being used.
The expected amount of time to completion is highly sample-dependent and cannot be estimated ahead of time.
Accurate T1 relaxation times and calibrated pulse lengths must have been obtained prior to starting.
Procedure
Procedure
Load pulse sequence zg.
Set the relaxation time d1 to 1.3 × T1, where T1 is the largest value previously measured.
Set the pulse power plw1 to a previously optimized 90° pulse power.
Using a previously optimized 90° non-selective pulse length corresponding to pulse power plw1, calculate a pulse length corresponding to the nuclear spin number of the observed nucleus:
| Nuclear Spin Number | Tip Angle | Factor | |
| 3/2 | 45° | 0.50 | |
| 5/2 | 30° | 0.33 | |
| 7/2 | 22.5° | 0.25 | |
| 9/2 | 18° | 0.20 |
Note
Using the tip angles above will result in the maximum sensitivity for resonances within the CT-selective limit with non-zero intensity for the non-selective limit. These angles should ensure that all resonances are observed, but they will not be homogeneously excited and relative intensities will not be reliable.
Set the pulse length p1 to the value calculated in Step 4.
Acquire the spectrum until the signal-to-noise ratio is satisfactory for all resonances.
Protocol references
Vega, A. J. Quadrupolar Nuclei in Solids. John Wiley & Sons, Ltd 2010-03. https://doi.org/10.1002/9780470034590.emrstm0431.pub2.
Protocol
NAME
Saturation Recovery for Quadrupolar Nuclei
CREATED BY
NMRFAM Facility
Protocol
NAME
Quadrupole Non-Selective Pulse Width Optimization
CREATED BY
NMRFAM Facility
Protocol
NAME
Quadrupolar Quantitative Bloch Decay
CREATED BY
NMRFAM Facility