Nuclear Magnetic Resonance Spectroscopy in Dynamic Magnetic Environments

CYNTHIA TURCIOS1,2, JACOB DONOHOUE1,2, JERICHO OVIEDO1,2,

MEGAN CASSIDY1,2, JOHN FROST PH.D.1,2,3,4 1 NASA HUNCH, 2 Cherry Creek School District, 3 American Chemical Society Science Coaches, 4picoSpin LLC.

Acknowledgements We would like to thank the following people and organizations for their

generous support and encouragement.

Florence Gold Ph.D. and the NASA Research and Development,

Education, and Reduced Gravity Offices

Mr. Richard Charles and the Cherry Creek School District

Mr. Gleb Gofin of KNF Labs

and

picoSpin LLC.

Conclusion The microgravity flights produced changes in the magnetic

environment equal to 83% of the maximum magnetic field change

experienced onboard the ISS. The NMR spectrum of both water and

acetone free nail polish were acquired and their basic spectral

characteristics were assessed and compared to our control spectra.

While there was some reduction in performance the line width (72

ppb) and SNR (339:1) were still found to be within the minimum

specification set by the manufacturer. We believe this demonstrates

the feasibility of effectively bringing the analytical power of NMR

spectroscopy to the research and service needs of the ISS.

Figure I:

NMR is extremely sensitive to changes in the external magnetic environment. This

plot shows the overlay of the first 100 spectra acquired during the microgravity flight.

The position of the Z-axis of the instrument’s magnetic field changes in relation to the

Earth’s magnetic field which causes a change in the total field experienced by the

protons under observation and therefore their Larmor frequency.

References:

1.) National Oceanic and Atmospheric Administration’s National Geophysical Data

Center Magnetic Field Calculator, IGRF 11 Model,

http://www.ngdc.noaa.gov/geomag-web/#igrfwmm, Accessed 6-11-12

2.) Heavens Above ISS-Orbit,

http://www.heavens-above.come/orbit.aspx?satid=25544,

Accessed 5-10-12

Figure III: Expansion of

Figure II during the first half

of the flight path while

headed due south. The

change in slope is due to the

relative orientation of the

instruments Z-axis and the

Earth’s magnetic field.

Figure IV: Expansion of Figure

II during the second half of the

microgravity flight. Because the

plane was now headed due

North the relative orientation of

the instruments Z-axis while the

plane climbing is opposite that

of when the plane was traveling

South.

Background and Concept A nuclear magnetic resonance spectrometer (NMR),

provides qualitative and quantitative chemical information

of purity and structure both rapidly and non-destructively.

NMR’s are typically large in size, which has prevented their

deployment in space. However, due to recent

advancements in the technology it has become feasible to

bring this technology to the International Space Station

(ISS). However, NMR is extremely sensitive to external

magnetic fields and the ISS experiences a 43 µT shift in the

Earth’s magnetic field with each orbit. We utilized the

parabolic flight path used by NASA’s microgravity flight

program to simulate these changes in the Earth’s magnetic

field and investigate the affects on the acquired spectrum

using a new-to-market commercially available NMR

spectrometer

Figure II: Larmor

frequency offset (Hz) /

change in the magnetic

field strength (µT) as a

function of time over the

course of the microgravity flight.