Rapid-melt DNP for multidimensional and heteronuclear high-field NMR experiments

Area of Science:

• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Hyperpolarization Techniques
• Analytical Chemistry

Background:

• Low sensitivity limits Nuclear Magnetic Resonance (NMR) for analyzing mass-limited samples.
• Dynamic Nuclear Polarization (DNP) is a hyperpolarization technique that enhances NMR sensitivity.
• Existing DNP methods often require specialized setups or are not compatible with liquid-state NMR.

Purpose of the Study:

• To demonstrate a novel 400 MHz rapid-melt DNP setup for enhanced liquid-state NMR.
• To enable high-sensitivity analysis of mass-limited samples using DNP-enhanced NMR.
• To combine solid-state DNP enhancement with standard liquid-state NMR experiments.

Main Methods:

• Development and implementation of a 400 MHz rapid-melt DNP system.
• Utilizing a stripline microcoil to detect 100 nL sample volumes in fused-silica capillaries.
• Employing low relaxation loss melting of small sample volumes due to their low heat capacity.

Main Results:

• Achieved proton enhancements of up to -175 in the liquid-state using the 400 MHz setup.
• Demonstrated the capability for heteronuclear DNP-NMR experiments with a double-tuned probe.
• Enabled signal averaging and multidimensional experiments due to unchanged sample composition.

Conclusions:

• The rapid-melt DNP setup effectively combines solid-state DNP enhancement with liquid-state NMR experiments.
• This method significantly improves sensitivity for chemical analysis of mass-limited samples.
• Rapid-melt DNP is a promising technique for high-throughput analysis of minute chemical quantities.