• Title, Summary, Keyword: N-nitrosodimethylamine

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Mutagenicity of N-Nitrosodimethylamine in Salmonella / Microsome Assay and the Effect of Vitamin C on the Formation of N-Nitrosodimethylamine (Salmonella / Microsome Assay 에서의 N-nitrosodimethylamine의 돌연변이 유발성과 N-nitrosodimethylamine의 생성에 대한 비타민 C의 영향)

  • 김소희;박건영;서명자
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.20 no.3
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    • pp.260-265
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    • 1991
  • The effective method to detect the mutagenicity of N-nitrosodimethylamineI (NDMA) by using Salmonella/microsome assay was studied. The Effect of vitamin C on the mutagenicity of the formed NDMA and during the formation of NDMA from nitrite and secondary amine was also investigated. Aroclor 1254-induced hamster S9 mix was more effective in activation NDMA than rat S9 mix induced by Aroclor 1254 or phenobarbital. Dimethyl sulfoxide and ethanol suppressed the mutagenic effect of NDMA, however, phosphate butter (pH 7.4), distilled water, 95% methanol and Tween 80 + water (1 : 4) were the appropriate dissolving system in the mutagenicity test of NDMA. Vitamin C did not show any inhibitory effect on the mutagenicity of the formed NDMA. However, the revertants of Salmonella typhinutrium TA 100 were significntly reduced (p<0.05) when vitamin C was added to the reaction mixture of nitrite and dimethylamine during the formation of NDMA. The amount of the formed NDMA was analyzed using HPLC and the level was decreased by about 95%. Thus it was concluded that vitamin C inhibited greatly the formation of NDMA from nitrite and dimethylamine.

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Formation and Treatment Methods of N-Nitrosodimethylamine (NDMA) in Water and Wastewater (상하수에서 N-Nitrosodimethylamine (NDMA) 발생 및 처리법 비교 분석)

  • Kim, Jongo;Lee, Woo-Bum;Park, Soo-Ho
    • Journal of Korean Society on Water Environment
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    • v.30 no.1
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    • pp.95-101
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    • 2014
  • Overall studies for the N-nitrosodimethylamine (NDMA) formation and treatment methods were conducted. In this study, occurrence in several countries and emerging treatment technologies of NDMA were generally reviewed. The NDMA formation was dependent on pH, contact time, and molar ratio (monochloramine/dimethylamine). The formation was rapidly increased when the molar ratio was greater than 1. It was likely that monochloramine could be related to stimulate NDMA formation. NDMA concentrations in water supply and wastewater plants after disinfection were approximately 10 ng/L and 100 ng/L, respectively. UV oxidation and adsorption processes are regarded as effective technologies for the NDMA removal. It is suggested that the UV oxidation with proper lamps is applied in water supply system.

Prediction and Comparison for the N-Nitrosodimethylamine(NDMA) Formation (N-Nitrosodimethylamine(NDMA) 생성에 관한 예측과 비교 연구)

  • Kim, Jong-O;Kim, Dong-Soo
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.4
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    • pp.402-406
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    • 2006
  • N-Nitrosodimethylamine(NDMA) formation was studied as a function of chloramine concentration at a fixed dimethylamine (DMA) concentration of 0.05 mM at pH 7 and 8. Regression equations were developed by molar ratio of chloramine to DMA. The NDMA formation was dependent on molar ratio(chloramine/DMA) and was different when the ratio is less or greater than 1. The formation of NDMA increased with increasing chloramine concentration and a linear correlation was examined between NDMA concentration and the ratio on a log scale. The developed regression was applied to previously reported data and relative errors ranged from -79 to 163%. Regression equations could provide a potential tool to predict NDMA formation for a simple and quick estimation in water supply systems.

Evaluation and Comparative Physical/Biological Removal Performance for Extremely Low-Concentration NDMA(N-nitrosodimethylamine) (극저농도 NDMA(N-nitrosodimethylamine) 물리적/생물학적 처리 효율 비교 평가)

  • Park, Seyong;Kim, Hui Joo;Kim, Moonil
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.2
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    • pp.55-61
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    • 2011
  • NDMA(N-Nitrosodimethylamine) has been considered as a carcinogenic pollutant even at extremely low-concentration (10ng/L). However, previous researches on NDMA have focused on mainly high concentration due to a difficulty of analysis. In this study, removal efficiencies were evaluated for individual or combined methods with PAC(Powder Activated Carbon), GS(Granular Sludge), MF(Microfiltration), UF(Ultrafiltration) and Silica gel(MCM-41, Diatomite, Spherical silica gel) at both aerobic and anaerobic conditions. Combined method of GS, PAC and UF membrane at anaerobic condition showed the highest removal efficiency of 65% while Silica gel showed the lowest removal efficiency of 6%. The outcomes of this study could be used further study of extremely low-concentration NDMA removal.

A Study on N-Nitrosodimethylamine (NDMA) Formation According to pH Variation (pH 변화에 따른 N-Nitrosodimethylamine (NDMA) 생성에 대한 고찰)

  • Kim, Jong-O;Clevenger, Thomas
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.4
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    • pp.390-393
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    • 2005
  • N-nitrosodimethylamine (NDMA), a potent carcinogenic, has recently been observed at drinking water supply systems in USA and Canada. The NDMA formation was studied as a function of chloramine concentration (0.001-0.1 mM) at a fixed dimethylamine (DMA) concentration of 0.05 mM at different initial pH (6, 7, 8). It was found that the NDMA formation rate varied with pH values. The formation of NDMA increased with increasing chloramine concentration and showed maximum yields of 2.4% and 1.6% at pH 7 and 8, respectively. A good correlation ($r^2>0.99$) was observed between the molar ratio (chloramine/DMA) and NDMA formation at pH 7 and 8. Linearity of the NDMA formation appeared to be related to chloramine concentrations.

N-Nitrosodimethylamine in the Kashmiri Diet and Possible Roles in the High Incidence of Gastrointestinal Cancers

  • Chikan, Naveed A.;Shabir, Nadeem;Shaffi, Sheikh;Mir, Manzoor R.;Patel, Trupti N.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.3
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    • pp.1077-1079
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    • 2012
  • The Kashmiri population is culturally distinct with special dietary features owing to the temperate climatic conditions of Kashmir valley. This has habituated the population to preserve food in smoked, pickled and sundried forms which include considerable amounts of $N$-nitroso compounds (NOCs). These are known to cause cytotoxicity, DNA damage, mutation, unscheduled DNA synthesis and DNA methylation. All of these changes at molecular level are known to contribute to the pathogenesis of cancer. One of the prominent NOCs found in Kashmiri food is $N$-Nitrosodimethylamine (NDMA). Here we review the occurrence of NDMA in sundried foods, dried fish, kehwa, traditional pickle, $Brassica$ $oleracia$ and $tobbaco$. We also discuss its possible role in the high prevalence of gastrointestinal cancers in Kashmir.

Distribution of Seven N-Nitrosamines in Food

  • Park, Jong-eun;Seo, Jung-eun;Lee, Jee-yeon;Kwon, Hoonjeong
    • Toxicological Research
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    • v.31 no.3
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    • pp.279-288
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    • 2015
  • N-nitrosamines, which are classified as carcinogens by IARC and US EPA, can be easily found in various foods. They are reaction products between nitrogen oxide and secondary amines, but can also be generated during fermentation. Ever since the 1960s, when nitrite, used as a preservative in processed meats, was suspected to generate N-nitrosamines, the usage of the food additive has been debated. However, the benefit of nitrite in food supply could not be ignored and the risk-benefit analysis has become a key issue in the use of the additive. For a risk analysis, an accurate estimation of the hazardous material is necessary; therefore, analytical methods for nitrosamines have continuously evolved from the 1950s. Solid supported liquid-liquid extraction and solid phase extractions have replaced the distillation for the clean-up steps, and tandem mass spectrometry is employed for higher selectivity and sensitivity. In the present study, for a better estimation of N-nitrosamine intake, the total diet study samples were prepared for the N-nitrosamines analysis. In order to obtain the most sensitive results, a partial preparation procedure was developed and modified for different food matrices. Among seven N-nitrosamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosodibutylamine, N-nitrosopiperidine, N-nitrosopyrrolidine, and N-nitrosomorpholine) analyzed in the present study, N-nitrosodiethylamine has shown the highest detection rate in agricultural foods, while N-nitrosodimethylamine has appeared most frequently in livestock and fishery food products. The concentration of N-nitrosodimethylamine was the highest in seasoning.

N-Nitrosodimethylamine(NDMA) Formation according to Various Factors (다양한 항목에 따른 N-Nitrosodimethylamine(NDMA) 생성에 관한 비교)

  • Kim, Jong-O
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.2
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    • pp.192-196
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    • 2007
  • In this study, a formation of N-nitrosodimethylamine(NDMA), a disinfection by-product, was investigated as a result of monochloramine addition in water. The NDMA formation was studied in terms of pH, dimethylamine(DMA), monochloramine concentration, and nitrogen composition in monochloramine. At a fixed DMA concentration of 0.01 mM or 0.05 mM, the NDMA formed concentration was quite different when the monochloramine to DMA ratio is less or greater than 1. The NDMA formation increased with increasing pH and a ratio of nitrogen composition in monochloramine to total nitrogen composition. At pH 7 and 8, more than five times higher NDMA formation was produced as a result of five times increase in DMA concentration. It was likely that monochloramine could be related to stimulate NDMA formation, if monochloramine may be produced with chlorine disinfection, in water treatment systems.

N-Nitrosamine of Marketing Radish Kimchi (시판 무김치 중의 N-Nitrosamine)

  • 성낙주;구경숙;신정혜;정미자;이수정
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.1
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    • pp.28-32
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    • 1999
  • A total of 18 marketing radish kimchi samples, 7 species of kakdugi, 6 species of chonggak kimchi and 5 species of dongchimi were analyzed for their N nitrosamine levels by gas chromatography thermal energy analyzer(GC TEA). N nitrosodimethylamine(NDMA) was the only volatile N nitr osamine found in this study and was positive in all collected samples. The average amount of NDMA for kakdugi, chonggak kimchi and dongchimi were 22.9, 13.7 and 23.4 g/kg, and the range were 3.3~ 35.9, 2.6~50.6 and 4.5~65.1 g/kg, respectively. The range of pH for all samples were 3.6~5.4 and the average recovery of internal standard(N nitrosodipropylamine) were 82.0%. NDMA amounts were highest in chonggakkimch (50.6 g/kg) and dongchimi(65.1 g/kg) among collected samples.

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