This primary study was undertaken to assess the use of EPR spectroscopy at different microwave frequencies to characterize the potential of geochemical materials as adsorbents for environmental remediation. Three sets of experiments were performed. In the first, a multifrequency EPR approach was used to study changes in the Fe signal corresponding to changes in Fe valence in two clay minerals containing structural iron. Spectra were collected at L-, S-, and X-band before and after treatment by buffered dithionite solutions. In the second set of experiments, a stopped-flow X-band resonator with attached mixer was used to estimate the homogeneous kinetics of the reaction between dithionite and chromate. Dithionite and chromate solutions at the same and widely differing ionic strengths were used and demonstrated a strong effect of ionic strength/viscosity on the reaction rate. The third set of experiments was conducted at X-band to attempt to identify surface Mn on single calcite crystals that had been treated with MnCl2 solutions. A strong signal from Mn impurities in the bulk crystal, however, shrouded the weak signal, if any, from the surface Mn.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001008-21
Application #
5222094
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
21
Fiscal Year
1996
Total Cost
Indirect Cost
Mao, Li; Liu, Yu-Xiang; Huang, Chun-Hua et al. (2015) Intrinsic Chemiluminescence Generation during Advanced Oxidation of Persistent Halogenated Aromatic Carcinogens. Environ Sci Technol 49:7940-7
Shan, Guo-Qiang; Yu, Ao; Zhao, Chuan-Fang et al. (2015) A combined experimental and computational investigation on the unusual molecular mechanism of the Lossen rearrangement reaction activated by carcinogenic halogenated quinones. J Org Chem 80:180-9
Li, Yan; Huang, Chun-Hua; Liu, Yu-Xiang et al. (2014) Detoxifying polyhalogenated catechols through a copper-chelating agent by forming stable and redox-inactive hydrogen-bonded complexes with an unusual perpendicular structure. Chemistry 20:13028-33
Sheng, Zhi-Guo; Huang, Wei; Liu, Yu-Xiang et al. (2013) Ofloxacin induces apoptosis via ?1 integrin-EGFR-Rac1-Nox2 pathway in microencapsulated chondrocytes. Toxicol Appl Pharmacol 267:74-87
Sheng, Zhi-Guo; Huang, Wei; Liu, Yu-Xiang et al. (2013) Bisphenol A at a low concentration boosts mouse spermatogonial cell proliferation by inducing the G protein-coupled receptor 30 expression. Toxicol Appl Pharmacol 267:88-94
Shao, Jie; Huang, Chun-Hua; Kalyanaraman, Balaraman et al. (2013) Potent methyl oxidation of 5-methyl-2'-deoxycytidine by halogenated quinoid carcinogens and hydrogen peroxide via a metal-independent mechanism. Free Radic Biol Med 60:177-82
Sheng, Zhi-Guo; Li, Yan; Fan, Rui-Mei et al. (2013) Lethal synergism between organic and inorganic wood preservatives via formation of an unusual lipophilic ternary complex. Toxicol Appl Pharmacol 266:335-44
Qin, Hao; Huang, Chun-Hua; Mao, Li et al. (2013) Molecular mechanism of metal-independent decomposition of lipid hydroperoxide 13-HPODE by halogenated quinoid carcinogens. Free Radic Biol Med 63:459-66
Huang, Chun-Hua; Shan, Guo-Qiang; Mao, Li et al. (2013) The first purification and unequivocal characterization of the radical form of the carbon-centered quinone ketoxy radical adduct. Chem Commun (Camb) 49:6436-8
Liddle, Brendan J; Wanniarachchi, Sarath; Hewage, Jeewantha S et al. (2012) Electronic communication across diamagnetic metal bridges: a homoleptic gallium(III) complex of a redox-active diarylamido-based ligand and its oxidized derivatives. Inorg Chem 51:12720-8

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