N Nitrosamines
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. Development of analyrtical methods for determination of N-nitrosamines in shampoo samples by liquid chromatography coupled to diode array, electrochemical and mass spectrometry detecto / Desenvolvimento de métodos para determinação de N-nitrosaminas em amostras de xampu por cromatografia líquida acoplada à detecção por arranjo de diodos, eletroquímica e espectrometria de massas
N-nitrosamines (NA) are N-nitroso compounds, showed to be carcinogenic in a wide variety of experimental animals. In addition, they also present mutagenic and teratogenic activities. N-nitrosamines have been found during the last three decades in a variety of consumer products, including cosmetic and personal care products, and their raw materials. The most
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/02/2011
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2. Contaminação de produtos de higiene e cosméticos por n-nitrosaminas
N-nitrosamines are carcinogenic compounds that have been found during the last three decades in a variety of consumer products, including cosmetic and personal care products, and their raw materials. These compounds are formed from amine precursors and nitrosating agents present in the formulations. This paper reviews the formation and occurrence of N-nitros
Química Nova. Publicado em: 2009
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3. Determination of N-nitrosamines and N-nitrosables substances in rubber teats and sothers by GC-TEA
N-Nitrosamines are receiving special attention because they present high mutagenic and carcinogenic potential. They can be found in several areas. In rubber, for example, they can be found in Nipples and Pacifiers. Spiegelhalder and Pressumann, have observed that N-Nitrosamines present in nipples and pacifiers could easily migrate to artificial saliva. They
Brazilian Archives of Biology and Technology. Publicado em: 2006-01
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4. Determinação de nitrosaminas volateis em salsichas "hot dog". / Determination of volatile nitromines in hot-dog sausage.
During the curing process, nitrite and nitrate are the principal ingridients udes for curing. They confer and colored color characteristic of the cured meat as sausage, and act as antioxidants and antimicrobial, comtrolling the growth of Clostridium botulinum. The most important toxic effect of the presence of nitrate and nitrite is the formation of nitrosam
Publicado em: 2006
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5. Fatores de risco para cancer de estomago: avaliação dos teores de nitrato e nitrito em linguiças
A dieta alimentar rica em nitrato e nitrito pode estar associada com cancer de estomago. Nitrato e nitrito são aditivos quimicos utilizados como conservantes, principalmente em produtos cárneos curados, com a finalidade de inibir o crescimento do Clostridium botulinum, produtor da toxina que causa botulismo. A presença desses aditivos nos alimentos é pre
Publicado em: 2006
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6. Desenvolvimento de metodos analiticos para determinação de nitrato, nitrito e n-nitrosaminas em produtos carneos
Nitrosamines are N-nitroso compounds formed in certain foods by the reaction of a nitrosating agent, derived from either nitrite salts or nitrogen oxide, with a substance having an amino group. The majority of nitrosamines tested in animals are carcinogenic, mutagenic, teratogenic and act transplacentally. This work describes analytical methods for the deter
Publicado em: 2004
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7. Pré-concentração de nitrosaminas a partir de amostras aquosas por extração em fase sólida e cromatografia capilar eletrocinética micelar
This paper describes the development of a methodology for solid phase extraction (SPE) and pre-concentration of nitrosamines from aqueous samples using granular activated charcoal as stationary phase. micelar electrokinetic capillary Chromatography (MEKC) was used for the separation and identification of the nitrosamines in the extracts. Using a sample with
Química Nova. Publicado em: 2003-03
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8. Prophage Induction in Escherichia coli (Lambda) by N-Nitrosamines
Carcinogenic N-nitrosamines were tested for their ability to induce λ in a lysogenic strain of Escherichia coli K-12 (58-161 F+). Dimethylnitrosamine, di-n-propylnitrosamine, methyl-n-propylnitrosamine, and N-nitrosopiperidine were shown to be inducers of prophage.
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9. Formation of N-nitrosamines from seconday animes and nitrite by resting cells of Escherichia coli B.
In the presence of resting cells of Escherichia coli B, the formation of N-nitrosamines from nitrite and secondary amines, such as dimethylamine and piperidine, was proportional to the incubation time and to the cell concentration. Optimum pH was 8.0. Boiled cells were incapable of nitrosating secondary amines. Although these experiments were carried out by
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10. Degradation of N-Nitrosamines by Intestinal Bacteria
A major proportion of bacterial types, common in the gastrointestinal tract of many animals and man, were active in degrading diphenylnitrosamine and dimethylnitrosamine, the former being degraded more rapidly than the latter. At low nitrosamine concentrations (<0.05 μmol/ml), approximately 55% of added diphenylnitrosamine, 30% of N-nitrosopyrrolidine, and
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11. Prophage Induction in Lysogenic Escherichia coli with N-Nitroso Compounds and Derivatives
Prophage induction in lysogenic Escherichia coli W1709 (ι) was determined for 29 N-nitroso compounds, 13 of their denitrosated derivatives, and 7 hydroxylamino and hydrazino analogues of nitrosamines. Minimal inducing concentrations of 0.1 to 2.0 μg/ml were demonstrated for eight nitrosamidines, and concentrations of 0.5 to 25.0 μg/ml were shown for six n
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12. Metabolism of tobacco-specific N-nitrosamines by cultured human tissues.
N'-Nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are present in cigarette smoke and snuff and are carcinogens in laboratory animals. In tobacco smokers, the buccal mucosa, trachea, esophagus, bronchi, and peripheral lung are exposed to smoke containing significant amounts of these N-nitrosamines. The results of the present