Pesticides containing nitrosamines

Fluorinated trifluralin ( oi, Oi, 0 -trifluoro-2,6-dinitro-N,N-dipropyl- -toluidine) was found to contain nitrosamines, and it seems likely that these arose by the nitrosation of the amine used in the condensation with the nitrated chlorobenzene intermediate in the synthesis or by nitration of the product, trifluralin itself. Nitrosamines have also been found in other pesticides prepared by similar nitration processes. 

A recent paper by EPA reviewed the results of analysis of about 300 pesticides for nitrosamines. A large number of amide, carbamate, organophosphate, triazine, urea derivatives and miscellaneous nitrogen-containing pesticides did not contain... 

Statement of E. F. Alder at the Environmental Protection Agency Hearing on Pesticide Products Containing Nitrosamines, Washington, DC, March 8, 1977... 

In recent years greater attention has been given to nitrogen containing pesticides and the possibility of their nitrosation in soil. The N-nitrosamines that form may arise from the parent pesticide or from a pesticide metabolite. The reaction calls for favourable pH conditions (pH 3-4) and excess nitrite. Under field conditions, the nitrosable residues are usually present in traces and only small quantities of these will actually be nitrosated in soils. However, the possibility exists that the small amounts of N-nitrosamines could be assimilated by plants. 

The persistence of the N-nitrosamine that may be formed in soil will depend on a host of conditions, such as soil type, organic matter content, clay content, pH, the microflora present in the soil, moisture content and temperature, etc. Superimposed on all these factors will be the chemical nature of the pesticide. The N-nitrosoatrazine ( ) formed in soil from the herbicide atrazine ( ) was shown to be rapidly disappeared (1). Thus, in soil W-nitrosoatrazine was observed after one week, but was absent 4 and 10 weeks later (Table IV). In contrast, N-nitroso-butralin (11 ) persisted much longer than N-nitrosoatrazine (9) under the same conditions (Table V) and was still detectable after 6 months (3). Our studies demonstrated that N-nitrosoglyphosate is persistent in the soil. Fox soil treated with 20 ppm of nitrite nitrogen and 740 ppm glyphosate contained about 7 ppm of N-nitrosoglyphosate even after 140 days (6). 

This far into a nitrosamine symposium it should hardly be necessary to point out that nitrosamines are technically just one of a group of Ji-nitroso compounds that also includes nitros-amides, nitrosocarbamates, nitrosoureas, etc. Or that nitrosa-table pesticides encompass all the categories just mentioned and more. Or that many diverse pesticides, including herbicides, insecticides, and fungicides have been converted to Ji-nitroso derivatives in the laboratory (a recent review contained a 3-page, probably incomplete, compilation), or that some of the Ji-nitroso compounds thus synthesized were determined to be carcinogenic in test animals or mutagenic in various assays. 

And yet, this left the six classes of pesticides which contained detectable levels of N-nitrosamines and had to be regulated. The moratorium on these pesticides still remains in force until a policy has been established. The Agency also could not ignore that some regulatory action might have to be taJten on those pesticides that are already registered and contain detectable levels of nitroso impurities. 

There are several routes for nitrosamine contamination in pesticides use of contaminated chemicals during synthesis, side reactions, use of nitrite as a preservative and corrosion inhibitor of metal containers and by reactions with environmental nitrosating agents. Over 300 formulations were shown to be contaminated with nitrosamines however, the main contamination was confined to 2,6-dinitroaniline herbicides, dimethylamino salts of phenoxyalkanoic acid herbicide, diethanolamine and triethanolamine salts of acid... 

N-nitrosamines are a group of compounds characterized by a nitroso group (N=0) attached to the nitrogen of an aromatic or aliphatic secondary amine. N-nitrosodi-N-propylamine is a suspected reaction byproduct from the nitrosation of di-N-propylamine. Two pesticides are suspected to contain some form of nitrosamines. 

The first edition of Food Analysis by HPLC fulfilled a need because no other book was available on all major topics of food compounds for the food analyst or engineer. In this second edition, completely revised chapters on amino acids, peptides, proteins, lipids, carbohydrates, vitamins, organic acids, organic bases, toxins, additives, antibacterials, pesticide residues, brewery products, nitrosamines, and anions and cations contain the most recent information on sample cleanup, derivatization, separation, and detection. New chapters have been added on alcohols, phenolic compounds, pigments, and residues of growth promoters. 

Highly selective to compounds containing nitrogen and phosphorus Nitrogen-phosphorus detector Organophosphorus pesticides (EPA 8141) Acrylonitrile (EPA 8031) Acetonitrile (EPA 8033) Nitrosamines (EPA 8070) Hydrocarbons, fats, oils, waxes may interfere with organophosphorus pesticides. 

Nitrosamines have been shown to be formed in soils in the presence of secondary amines and nitrite at acid pH values. ° Many agricultural chemicals contain structures that can be degraded to secondary amines. The excessive and widespread use of these pesticides may result in accumulation of secondary amines in localized environments, and may contribute to the formation of nitrosamines. 

Hazardous Decomp. Prods. CO, CO2, NO ammonia, nitric acid, nitrosamines, irritating or toxic fumes NEPA Health 3, Elammability 3, Reactivity 0 Storage Store in cool, dry, ventilated area in closed containers, away from heat, flames, sparks do not store in reactive metal containers Uses Intermediate in mfg. of rubber accelerators, surfactants, dyes, polymers, DEET pesticides, textile specialties, petroleum chemicals selective solvent buffer flotation agent polymerization inhibitor in electroplating sol ns. corrosion inhibitor for metals depilatory for hides in food-pkg. adhesives in pharmaceutical injectables catalyst in food-contact PPO resins activator in food-contact rubber articles for repeated use... 

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