title: Superoxide, amine buffers and tetranitromethane: a novel free radical chain reaction.
abstract: The amine buffer Tris slowly reduces tetranitromethane (TNM) to the nitroform anion in a non-accelerating reaction. The amine buffers HEPES and MOPS also (slowly) react with TNM but the dialkylaminoalkyl radicals formed from these two buffers undergo further reactions resulting in a rapid, accelerating, free radical chain process whereby the amine is oxidized and TNM reduced. The chemical functionality in any reaction component, not necessarily the buffer, required for this radical chain mechanism is >N-CH<. In the presence of such groups, the quantification of superoxide by TNM is impossible.
authors.affiliation: Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario.
authors.forename: G R
authors.initials: GR
authors.lastname: Hodges
authors.forename: K U
authors.initials: KU
authors.lastname: Ingold
mesh_terms: D000588:Amines / Q000737:chemistry*; D002021:Buffers; D005609:Free Radicals / Q000737:chemistry*; D006531:HEPES; D009025:Morpholines; D010084:Oxidation-Reduction; D013481:Superoxides / Q000737:chemistry*; D013774:Tetranitromethane / Q000737:chemistry*
chemical_list: D000588:Amines; D002021:Buffers; D005609:Free Radicals; D009025:Morpholines; D013481:Superoxides; C008550:morpholinopropane sulfonic acid; D013774:Tetranitromethane; D006531:HEPES