skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Fusinite: A coal-derived EPR probe for O[sub 2]. Mechanism and application in vivo and in vitro. [EPR (electron paramagnetic resonance)]

Miscellaneous ·
OSTI ID:7170923

Fusinite, an inertinite coal maceral, exhibits a symmetric and exchange-narrowed electron paramagnetic resonance (EPR) line (g = 2.00276), with a first derivative peak-to-peak linewidth ([Delta]B) which is reversibly broaded by molecular O[sub 2]. To explain the mechanism of this type of broadening, pulse and multifrequency EPR measurements (0.25-250 GHz) were carried out in conjunction with O[sub 2] adsorption isotherm studies. The data suggest that, at ambient temperatures, homogeneous broadening of the EPR line of fusinite probably occurs by the exchange modulation of a group of delocalized unpaired electrons at the surface of fusinite by physical adsorbed O[sub 2]. At temperatures below 260[degrees] K, dipole-dipole mechanism begin to contribute more to the broadening of this component. The possibility of two different classes of sites for interaction with O[sub 2] is discussed. The extent of broadening per unit concentration of molecular oxygen is unusually large. This paramagnetic property of fusinite, combined with its very table physiochemical properties and low toxicity, is of utility for the measurement of the concentration of oxygen or [O[sub 2]] in vivo and in vitro. Fusinite particles, when prepared in subcellular dimensions, can be endocytosed by chinese hamster ovary (CHO) cells in vitro. This is useful for intracellular measurements of [O[sub 2]] with commercially available EPR spectrometers operating at 9.1-9.3 GHz. For in vivo measurements of [O[sub 2]] with low frequency EPR (1.1-1.3 GHz), fusinite provides a sensitive and persistent means to measure [O[sup 2]]. Fusinite particles were implanted into the gastrocnemius muscle of A/J mice; these particles remained interstitially in the same position for months with undiminished sensitivity to [O[sub 2]] and no specific toxic effects. Fusinite is especially useful when the solubility of O[sub 2] in the surrounding medium is unknown.

Research Organization:
Illinois Univ., Urbana, IL (United States)
OSTI ID:
7170923
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English