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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.