Title

Nuclear spin relaxation in NMR spectroscopy

Presenter Information

Kelsey E. Brakensiek

Department

Chemistry

Major

Chemistry

Research Advisor

Woelk, Klaus

Advisor's Department

Chemistry

Funding Source

Materials Research Foundation & CASB FYRE Program

Abstract

Several hyperpolarization techniques are known to enhance the intrinsically low sensitivity of NMR spectroscopy. The enhanced sensitivity allows users to record spectra from very low sample concentrations, or improve the spatial resolution and imaging contrast in medical MRI. The relaxation of hyperpolarization to thermodynamic equilibrium is often viewed as the limiting factor for NMR and MRI enhancements. When hyperpolarization techniques are used, relaxation may not follow a mono-exponential but a multi-exponential decay. To accurately describe relaxation of hyperpolarization, a numerical algorithm is introduced which uses relaxation-matrix calculations that apply to both hyperpolarized and regular spin arrangements. For two-spin systems, the algorithm provides four eigenvectors with their respective eigenvalues, which are then used to model the relaxation of both regular and hyperpolarized spin-state distribution. An extension to three-spin systems leads to six Eigenvectors. Standard inversion-recovery and hyperpolarized spin-state experiments are used to provide evidence for the validity of the new algorithm.

Biography

Kelsey Brakensiek is a junior in Chemistry from O’Fallon, Missouri. She transferred to Missouri University of Science and Technology in the Fall of 2018 after receiving her Associate of Science degree in Chemistry from St Charles Community College, where she combined her passions for chemistry and helping others by tutoring chemistry for two years. She joined Dr. Woelk’s team in the spring of 2019 under the FYRE program, where she plans to continue her undergraduate research until graduation. She also serves as safety officer for the research team on Chem E Car. She hopes to receive her PhD in chemistry, and to work in industry, focusing on renewable energy and green chemistry.

Research Category

Sciences

Presentation Type

Oral Presentation

Document Type

Presentation

Award

Sciences oral presentation, First place

Location

Ozark Room

Presentation Date

16 Apr 2019, 10:30 am - 11:00 am

This document is currently not available here.

Share

COinS
 
Apr 16th, 10:30 AM Apr 16th, 11:00 AM

Nuclear spin relaxation in NMR spectroscopy

Ozark Room

Several hyperpolarization techniques are known to enhance the intrinsically low sensitivity of NMR spectroscopy. The enhanced sensitivity allows users to record spectra from very low sample concentrations, or improve the spatial resolution and imaging contrast in medical MRI. The relaxation of hyperpolarization to thermodynamic equilibrium is often viewed as the limiting factor for NMR and MRI enhancements. When hyperpolarization techniques are used, relaxation may not follow a mono-exponential but a multi-exponential decay. To accurately describe relaxation of hyperpolarization, a numerical algorithm is introduced which uses relaxation-matrix calculations that apply to both hyperpolarized and regular spin arrangements. For two-spin systems, the algorithm provides four eigenvectors with their respective eigenvalues, which are then used to model the relaxation of both regular and hyperpolarized spin-state distribution. An extension to three-spin systems leads to six Eigenvectors. Standard inversion-recovery and hyperpolarized spin-state experiments are used to provide evidence for the validity of the new algorithm.