Effect of magnetic particles on NMR spectra of Murchison meteorite organic matter and a polymer-based model system.
Organic matter from the Murchison meteorite shows pronounced spinning sidebands of the (1)H MAS NMR spectrum and exhibits a large bulk magnetization of 0.75emicro/g extrapolated to 94kOe at 300K. By comparison with data of diamagnetic polystyrene and laponite clay mixed with ferrimagnetic gamma-Fe(2)O(3) nano-particles, we show that the spinning sidebands arise from a combination of dipolar couplings of a given (1)H to magnetic particles, seen in a backscattered-electron image, and to other protons. Signal loss and significant broadening of protonated-carbon peaks in (13)C MAS NMR spectra of polystyrene with Fe(2)O(3) nano-particles is demonstrated, and implications for (13)C NMR spectroscopy of Murchison meteorite are discussed.
Levin
E M
EM
Ames Laboratory DOE, Iowa State University, Ames, IA 50011-3020, USA.
Bud'ko
S L
SL
Mao
J D
JD
Huang
Y
Y
Schmidt-Rohr
K
K