THERE is much concern about the possible widespread occurrence of N-nitroso compounds in the environment1. Many N-nitroso compounds are known to be carcinogenic2,3, and some ‘Volatile’ nitrosamines have been found in cured food products such as smoked fish4–6, cooked bacon (ref. 5 and United States Department of Agriculture News Release, 1972), and sausages5. N-nitroso compounds are generally unstable and have a wide range of physical properties, particularly with respect to volatility and solubility.