Single and Double-selective Split-inversion Pulse And Recovery (SIP-R) Sequences for Targeted T1 Relaxation Measurements
Abstract
Split-Inversion-Pulse and Recovery (SIP-R) is a recently introduced NMR methodology for acquiring spin-lattice relaxation data with a robust decay-to-zero intensity profile as a function of recovery time. This decay-to-zero behavior is particularly advantageous for extracting multiple relaxation times and coefficients using inverse Laplace transformation (ILT) algorithms. In this study, two frequency-selective adaptations of SIP-R are introduced, incorporating either one or two frequency-selective pulses in the SIP-R dual-scan experiment to excite only specific spectral regions. In a test using a non-viscous, small-molecule solution of ethanol in D₂O, both single- and double-selective SIP-R sequences reproduced reasonably well the relaxation times obtained with the non-selective SIP-R method. However, the double-selective SIP-R experiment introduced additional, shorter relaxation times, which were interpreted as artifacts due to the extended duration of the second frequency-selective pulse. Applying the non-selective SIP-R method to a polymer hydrogel enabled the quantitative differentiation of freely moving water molecules (95 %) and water tightly bound to the polymer chains (5 %). The frequency-selective SIP-R variants revealed strong NOE effects between water and polymeric amide resonances, similar to previous findings that suggest strong interactions between water molecules and amine groups in a different type of polymer hydrogel.
Recommended Citation
Z. G. Mayes et al., "Single and Double-selective Split-inversion Pulse And Recovery (SIP-R) Sequences for Targeted T1 Relaxation Measurements," Journal of Magnetic Resonance, vol. 375, article no. 107884, Elsevier, Jun 2025.
The definitive version is available at https://doi.org/10.1016/j.jmr.2025.107884
Department(s)
Chemistry
Second Department
Materials Science and Engineering
Keywords and Phrases
Decay-to-zero functionality; Inverse Laplace transformation (ILT); Longitudinal relaxation; Nuclear Overhauser effect (NOE); Polymer hydrogels; Relaxation artifacts; Selective excitation; Spin-lattice relaxation; Split-inversion pulse and recovery (SIP-R); Water-amide interactions
International Standard Serial Number (ISSN)
1096-0856; 1090-7807
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Elsevier, All rights reserved.
Publication Date
01 Jun 2025
Comments
Missouri University of Science and Technology, Grant None