groups is selected from a c 2 up to c 8 alkyl or substituted alkyl wherein the substituents are selected from carboxyl acetyl amido or hydroxy while the other r group is selected from methyl ethyl propyl or butyl exemplary thiol compounds contemplated for use herein include thiol containing amino acids e g cysteine n acetyl cysteine and the like thiol containing peptides thiol containing proteins e g albumin insulin hemoglobin lysozyme immunoglobulins u03b1 2 macroglobulin fibronectin vitronectin fibrinogen and the like glutathione thiol containing carbohydrates thiol containing nucleotides and the like suitable physiologically compatible aqueous media contemplated for use herein as a nitric oxide trapping agent include saline sterile water phosphate buffered saline culture media balanced salt solutions and the like suitable apolar oxygenated solvents contemplated for use herein as a nitric oxide trapping agent include fluorinated cycloaliphatic compounds e g a perfluoroadamantane a perfluorodecalin a perfluorohexane and the like a fluorinated aromatic compound e g a perfluorobenzene a perfluorotoluene and the like a fluorinated carboxylic acid e g perfluorolauric acid and the like additional agents useful as nitric oxide trapping agents in the practice of the present invention include superoxide anion radicals peroxynitrite xanthine hypoxanthine xanthine oxidase system peroxides superoxide dismutase antibodies directed against free radical adducts griess.