Diethyl nitrosamine

Ito et al. (1995) examined the combined dietary administration to rats of 19 organophosphate pesticides and 1 organochlorine pesticide, aU permitted for use in Japan, each at its ADI level. The dietary exposure at this level did not enhance the development of diethyl nitrosamine initiated pre-neoplastic lesions whereas at 100 times the ADI, the number and area of lesions were increased. The authors concluded that the study provided direct support for the present use of the safety factor approach in the quantitative hazard evaluation of pesticides. 

Bipyridylium Herbicides Di methyln i trosami ne Diethyl nitrosamine... 

Armstrong MJ, Galloway SM. 1993. Micronuclei induced in peripheral blood of E p-PIM-1 transgenic mice by chronic oral treatment with 2-acetylaminofluorene or benzene but not with diethyl-nitrosamine or 1,2-dichloroethane. MutatRes 302(l) 61-70. 

Fiddler W, Pensabene JW, Doerr RC, et al. 1977. The presence of dimethyland diethyl-nitrosamines in deionized water. Fd Cosmet Toxicol 15 441-443. Fiddler W, Pensabene JW, Kimoto WI. 1981. Investigations of edible oils for volatile nitrosamines. J Food Science 46 603-605. 

Canuto, R. A., G. Muzio, M. Maggiora, M. E. Biocca, and M. U. Dianzani, 1993. Glutathione-S-transferase, alcohol dehydrogenase and aldehyde reductase activities during diethyl-nitrosamine-carcinogenesis in rat Uver. Cancer Jl 68 177—183. 

Konishi Y, Takahashi S, Ohnishi T, Denda A, Mikami S, Emi Y, Nakae D (1983) Possible role of poly(ADP-ribose) polymerase on the early stage of liver carcinogenesis by diethyl-nitrosamine in rats. In Miwa M et al. (eds) ADP-ribosylation, DNA repair and cancer. Jpn Sci Soc Press, Tokyo/VNU Science Press, Utrecht, p 309... 

Habs, M., and Schmahl, D., 1981, Inhibition of the hepatocarcinogenic activity of diethyl nitrosamine (DENA) by ethanol in rats, HepatchGastroenterol. 28 242. 

Aerojet (fine chemicals division now acquired by AMPAC) also has reported technology to prepare and use diazomethane on large scale from the reaction of NaOH with N-methyl-N-nitrosamine. This process differs for the Phoenix process in that relatively large amounts of a low-boiling volatile solvent, diethyl ether, are uhlized to limit bulk liquid temperatures and minimize headspace concentrations of diazomethane [22]. 

The diazo compound (181a), prepared from the nitrosamine, cyclized to a pyrrolopyrazoline in 80% yield.98 The diazo compound (181b), prepared from diethyl diazomalonate and allylamine, cyclized similarly but at a much more rapid rate. This is consistent with the lowered LUMO of the dipole of (181b), substituted with an ester group here the dipole LUMO-dipolarophile HOMO is the likely dominant interaction. The N—N double bond of the pyrrolopyrazoline products was readily isomerized to afford A2-isomers. 

Volatile nitrosamines, dimethyl, diethyl and dipropyl nitrosamines Capillary column GC-MS [193]... 

Kataoka, H., Shindoh, S., and Makita, M., Selective determination of volatile A-nitrosamines by derivatization with diethyl chlorothiophosphate and gas chromatography with flame photometric detection, J. Chromatogr. A, 723, 93-99, 1996. 

The XAD-type resins have been used to remove A-nitrosamines from water samples and sewage effluent. The samples are filtered to remove suspended particles and then they are passed through a column at a flow rate between 11 and 15 ml/min. Acetone-DCM or DCM-diethyl ether (75 25) have been used to desorb the organic compounds retained by the XAD resin. After an appropriate concentration, the final solution can be analyzed directly by HPLC or GC. Alternatively, it may be necessary to perform a further clean-up of the extract prior to the analysis. This clean-up will depend largely on the nature of the water samples extracted and on the complexity of the organic materials present in the sample. 

For determining volatile nitrosamines in mainstream and sidestream, Kataoka et al. employed 5% hydrochloric acid as the tripping solution and diethyl ether containing 25% 2-propanol as the extractant. A similar approach was used by Cardenes et al. using DCM as the extractant. 

Nitrosamlnes - Nitrosamines depress ui vivo cytochrome P-450 concentrations and inhibit xenobiotic metabolism.Dimethyl-, diethyl-, and dipropylnitrosamlnes have recently been shown to cause the vivo accumulation of abnormal hepatic pigments.The pigment obtained with diethylnitrosamine, identified as N-(2-hydroxyethyl)protoporphyrin IX, did not detectably contain N-ethylprotoporphyrin IX. The demonstration that N-ethylprotoporphyrin IX is not a precursor of the N-(2-hydroxyethyl) derivative implies that the heme reacts with a preformed 2-hydroxyethyl moiety (S-hydroxylation of diethylnitrosamine is known to occur) or is alkylated during the oxidation of diethylnltrosamine-derived ethylene. 

N-Nitrosamines are directly determined as the free forms by GC-TEA. However, other GC- and LC-based methods have been referenced based on the application of derivatization reactions. Precolmnn or postcolumn derivatization of the N-nitroso compounds very often provides unsatisfactory sensitivities. Better results can be obtained by previous denitrosation of the NOCs and subsequent detection of liberated secondary amines via derivatization. Denitrosation can be obtained by reaction with hydrobromic acid and the subsequent derivatization of the secondary amines formed by reaction with typical derivatization agents such as dansyl chloride or diethyl chlorothiophosphate. 

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