US Patent 4,256,462
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
N-nitrosamines are reacted with a denitrosating agent to cleave the N--NO bond and yield nitric oxide which may be analyzed to determine both qualitatively and quantitatively, the N-nitrosamine content of a test sample. The denitrosating reagent has the advantage of being useful, even in the presence of substantial amounts of water, and comprises a mixture of glacial acetic acid and a concentrated inorganic acid which is either phosphoric acid or sulfuric acid. The volume ratio of glacial acetic to concentrated acid is within the ratio of from 1:2 to 5:1. This acid component mixture is combined with from about 0.1% to about 5% by weight of soluble inorganic bromide or iodide salt.
Frank, Clyde W.; Nord, Paul J.; and Cox, Robert D. Method and composition for determination of n-nitrosamines. US Patent 4,256,462 filed December 28, 1979 and issued March 17, 1981. https://ir.uiowa.edu/patents/23