Journal of Environmental Sciences
·
2016
·
IF 2.208
Xianze Wang,Zhongmou Liu,Chi Wang,Zhian Ying,Wei Fan,Wu Yang
The presence of mutagenic and carcinogenic nitrosamines in water is of great concern. In this study, seven nitrosamines including N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPyr), N-nitrosopiperidine (NPip), N-nitrosodi-n-propylamine (NDPA), and N-nitrosodi-n-butyl-amine (NDBA) were investigated in river water and ground water samples collected from 5 representative cities (Jilin, Songyuan, Harbin, Jiamusi and Tongjiang) along the Songhua River. The total concentrations of nitrosamines in ground water were n.d. (not detected) to 60.8 ng/L, NDMA was the most frequently detected nitrosamines in ground water, followed by NDEA and NPip. Relatively high detected frequency and concentrations of NDMA were also observed in river water samples, and the total nitrosamines' concentration at midstream is always higher than that at upstream and downstream. After 24 hr chlorination, concentration of NDMA, NDBA was obviously increased but NDEA was reduced. Furthermore, UV 254 showed a better relationship with NDMA-FP rather than dissolved organic carbon (DOC), NH 4 -N, and TDN.
研究领域:
环境科学
·
公共卫生
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DOI
PubMed
高影响因子
Oncotarget
·
2017
·
IF 5.168
Jie Gao,Gao-Ju Wang,Zhao Wang,Na Gao,Jing Li,Yun-Fei Zhang,Jun Zhou,Hong-Xin Zhang,Qiang Wen,Han Jin,Hai-Ling Qiao
Hepatofibrosis, which leads to cirrhosis and eventual hepatocellular carcinoma, is a common response to chronic toxin-mediated liver injury. Nitrosamines are potent hepatotoxic agents that cause necrosis and subsequent fibrosis in the liver as a result of cytochrome P450 2E1 (CYP2E1)-dependent metabolism, which generates toxic metabolites that form adducts with nucleic acids, leading to hepatotoxicity and mutagenesis. Herein, CYP2E1 activity and content were determined in fibrotic liver tissue from patients with hepatocellular carcinoma. The relationship between CYP2E1 innate activity and hepatofibrogenesis was evaluated, the effect of inhibition of CYP2E1 activity on hepatofibrosis was determined in a Sprague-Dawley rat model of diethylnitrosamine-induced hepatofibrosis. The results demonstrated that the CYP2E1 activities in human fibrotic tissues are significantly higher than that in normal liver tissues. In rats treated with diethylnitrosamine, the livers demonstrated various degree of fibrotic changes and collagen deposition in individual rats. The Ishak score, which determines the stage of fibrosis, correlated with CYP2E1 innate activity, with greater fibrosis in rat livers with higher CYP2E1 innate activity. Inhibition of CYP2E1 during diethylnitrosamine treatment decreased hepatofibrosis and there was an inverse correlation between the degree of inhibition and the extent of hepatofibrosis. Therefore, high CYP2E1 activity is a risk factor for hepatofibrogenesis induced by nitrosamines.
研究领域:
医学
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毒理学
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肝脏研究
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Jian-Bo Chen,Baosheng Li,Ying Xiong,Jie Sun
Two new fluorescent probes based on a coumarin core have been developed for the detection of nitramines (RDX and HMX) via responding to their photo-degradated nitrogen dioxide (NO 2 ). Although both probes contain the same fluorophore and recognition site, they display different fluorescent responses to NO 2 and nitramines. 8- O xime-7-dimethylamino-coumarin (8-ODC) emits traditional turn-on fluorescence toward NO 2 , which is based on the C N isomerization. In contrast, 3- O xime-7-dimethylamino-coumarin (3-ODC) exhibits a unique turn-off response with strong fluorescence quenching (about 98%) as a result of a twisted intramolecular charge transfer mechanism (TICT). In addition, 3-ODC offers a highly selective and sensitive determination of nitramines via detecting NO 2 in solution. The limit of detection of 3-ODC for NO 2 , HMX and RDX was 90 ppb, 60 nM and 90 nM, respectively. Notably, main interferents such as TNT, PETN, NO, NO 2 + and H 2 O 2 showed no obvious interference to the detection of NO 2 and nitramines. Therefore, a novel fluorescent probe (3-ODC) based on the TICT mechanism was firstly developed to detect NO 2 and nitramines by fluorescence quenching with high selectivity and sensitivity.
研究领域:
分析化学
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环境科学
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爆炸物检测
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DOI
高影响因子
JOURNAL OF ENVIRONMENTAL ENGINEERING
·
2021
·Vol. 147
·期 10
·04021038
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IF 1.86
Yanling Guo,Yanan Cheng,Bingli Wang,Xueke Li,Wanfeng Wang
Nitrosamines have become a focus of considerable research because of their carcinogenicity and environmental universality. In this study, to effectively remove nitrosamines, biological activated carbon (BAC) was acclimatized by a nitrosamine-reducing bacterial strain, and zero-valent iron (Fe0)-assisted BAC was used to degrade nitrosamines from aqueous solution. The influencing factors and degradation mechanism were investigated. Compared with activated carbon (AC), the removal efficiency of more strongly polar nitrosamines by BAC and BAC_Fe0 increased prominently (21.0%–32.3%), yet there was no change between BAC and BAC_Fe0. The highest ratios of nitrosamine degradation by BAC_Fe0 were 49.8%–99.0%, and degradation reaction kinetics conformed best to a pseudo-second-order model (?2>0.9269). The rate constants ?obs for six nitrosamines ranged from 3.4×103 to 6.9 × 105 (M · s)−1. Additionally, the removal ratios and ?2 of the linear nitrosamines partially scaled with their molecular weight, Log??, and Log??? (?2=0.5661−0.952). All nitrosamines were degraded within 30 min under strong acidic conditions; the removal ratios increased by 11.2%−23.1% under anaerobic conditions, but were decreased by ∼10% in the presence of humic acid. The primary degradation products were secondary amines, methylamine, formic acid, nitrate, and nitrite resulting from the reduction of Fe0 and biodegradation by the nitrosamine-reducing bacteria.
研究领域:
环境科学
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微生物学
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材料科学
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DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2018
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IF 6.042
Zhenyang Xie,Huilin Ge,Jiayan Du,Tao Duan,Guangcheng Yang,Yi He
We report a visual colorimetric assay for detection of nitramine explosives such as 1,3,5-trinitro-1,3,5-triazinane (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) using a smartphone. This assay is based on compartmentalizing incompatible tandem reactions in Pickering emulsions. The alkaline hydrolysis of RDX or HMX in one Pickering emulsion produces nitrite ions, which autodiffuse into the other Pickering emulsion to form nitrous acid. It oxidizes the 3,3′,5,5′-tetramethylbenzidine (TMB) to generate yellow TMB diimine. The RGB component change of the optical images is applied to quantitatively determine the RDX and HMX at different reaction temperatures. A distinct color change occurs at RDX and HMX concentrations of 1.2 and 12 μM, respectively. The adjusted intensity increases linearly with the increase of the logarithms of the concentrations of RDX and HMX in the range of 1.2–90 μM and 12–90 μM, respectively. The limits of detection of RDX and HMX are 96 and 110 nM, respectively. Importantly, this assay is employed for the detection of RDX and HMX in real water, proving the applicability of the assay in real-world samples.
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Siying Tan,Shaojie Jiang,Yangzhou Lai,Qiuhong Yuan
Cationic polymers, which are commonly used as flocculants and coagulant aids in water and wastewater treatment , have been recently reported to promote the formation of nitrosamines . Most of the findings to date are based on poly (epichlorohydrin dimethylamine) and poly (diallyldimethylammonium chloride), while few studies have considered nitrosamines formation of polyacrylamides. In this work, the nitrosamines formation from non-ionic, anionic and cationic polyacrylamides was evaluated. Moreover, the effects of chemical structures of cationic polyacrylamides (including molecular weight , charge density, and monomers) on nitrosamines formation were investigated. The results revealed that the highest amount of nitrosamines formation was formed from cationic polyacrylamide, followed by non-ionic polyacrylamide and anionic polyacrylamide. Molecular weight and various cationic monomers showed no significant effects on nitrosamines formation, but monomers generated significantly higher amount of nitrosamines formation than cationic polyacrylamides. Nitrosamines formation increased with the increasing charge density of cationic polyacrylamides, and FTIR analysis results showed that the quaternary amine groups preferentially reacted with chloramines than with amide groups. This work shed new light on the nitrosamines formation from water and wastewater treatment polymers.
研究领域:
环境科学
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水处理工程
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DOI
PubMed
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Peizeng Yang,Hailing Chu,Jiating Liu,Teng Zhang,Junhe Lu
Sulfate radical (SO 4 •− ) advanced oxidation processes (SR-AOPs) are efficient for degrading a broad spectrum of contaminants. This study demonstrates that the existence of environmentally relevant concentrations of nitrite (NO 2 − ) can lead to the formation of N -nitrosodimethylamine (NDMA), a probable human carcinogen, when heat activated peroxydisulfate (heat/PDS) is applied to address contaminants with dimethylamine moieties, such as tetracyclines. NO 2 − effectively competes with tetracyclines for SO 4 •− at a high second-order reaction rate constant of 8.8 × 10 8 M −1 s −1 , thus suppressing the degradation. Simultaneously, SO 4 •− reacts with NO 2 − to form the nitrogen dioxide radical (NO 2 • ) which rapidly dimerizes to a potent nitrosating agent named dinitrogen tetroxide (N 2 O 4 ). N 2 O 4 , in turn, attacks the dimethylamine moiety in tetracyclines via nucleophilic substitution, contributing to the degradation of parent compounds and generating an active intermediate that quickly decomposes to NDMA, along with the release of R + and NO 3 − . The released R + can be further oxidized by SO 4 •− to form phenolic intermediates which combine with NO 2 • to generate nitrated products. When 5 μM oxytetracycline (OTC) was treated with 0.5 mM PDS in the presence of 20 μM NO 2 − at 60 °C, the highest formation of NDMA was 0.045 μM in 1 h. NDMA formation was also observed for other compounds with dimethylamine moieties, such as methylene blue, phenylurea herbicides, etc., with the molar yield ranging from 0.07 to 3.53 %, negatively related to the R-N bond dissociation energy of the precursors. These findings suggest that NDMA can be commonly generated when SO 4 •− is applied to the degradation of dimethylamine pollutants in wastewater treatment or groundwater remediation where NO 2 − ubiquitously exists, which may pose a serious threat to the aquatic environment.
研究领域:
环境科学
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毒理学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Yi-Hsueh Chuang,Chia-Shun Chou,Yi-Lin Chu
Chlorination of ammonia or chloramine-containing waters induces breakpoint chlorination reactions, producing a hydroxyl radical (•OH), but enhances the formation of undesirable N-nitrosamines. The prevailing view attributes •OH formation to a nitrosyl intermediate derived from the hydrolysis of dichloramine, but this pathway is unlikely at neutral or acidic pH. This study reveals a novel mechanism where •OH is generated via interactions between trichloramine (NCl3) and dichloramine (NHCl2), which also form nitrosation agents. Our experiments demonstrated that the NCl3–NHCl2 interaction degrades micropollutants with kinetics 2–3 times faster than breakpoint chlorination. Using electron paramagnetic resonance, we detected •OH in the NCl3–NHCl2 reaction. Micropollutant removal was unimpaired under low dissolved oxygen (O2(aq)) conditions, aligning with negligible O2(aq) changes during the NCl3–NHCl2 reaction and suggesting O2(aq) does not participate in •OH formation. Using benzene as a probe in 18O-labeled H2O, we confirmed water contributes to the oxygen source of •OH in NCl3–NHCl2 interactions, through which parallel reactions occur, leading to the formation of one mole of •OH alongside 1.92 mol of N2. A kinetic model developed in this study accurately predicted •OH and N2 and demonstrated the NCl3–NHCl2 interaction as the primary pathway for •OH formation in breakpoint chlorination, providing new insights into breakpoint chemistry.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
Natural Product Communications
·
2020
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IF 0.468
YanHua Tian,HuiZhi Du,Li Wang,ShiFei Li,Lu Zhang,LiWei Zhang
Diospyros lotus L. leaves are used as a functional tea and folk medicine in several Asian countries. This study aimed to evaluate the effects of phenolic extracts of the leaves on scavenging nitrite and inhibiting N-nitrosamines (NAs) formation and to determine the active ingredients responsible for these effects. Of the 7 fractions (Fr1-Fr7) prepared from the extract of D. lotus leaves, Fr5 contained the highest phenolic content and exhibited the strongest activity. Five active ingredients of Fr5 were discovered, and 4 of them were identified as myricitrin (Mytr), myricetin (Myt), myricetin-3-O-β-d-glucoside (Myt-Glc), and myricetin-3-O-β-d-galactoside (Myt-Gal). The content of Mytr was much higher than those of the other 3 ingredients, both in Fr5 and extracts of D. lotus leaves. Finally, Mytr and Myt were proved to have stronger activities by the 1,1-diphenyl-2-trinitrophenyl hydrazine scavenging, nitrite scavenging, and inhibition of NAs formation assays. These results indicated that Mytr was the main active ingredient of D. lotus leaves. Myt, Mytr, and Fr5 from the leaves could be used as natural agents for antioxidant, nitrite scavenging, and inhibition of NAs formation in food and the human body.
研究领域:
食品科学
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植物化学
·
药理学
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DOI
高影响因子
Food & Function
·
2019
·Vol. 10
·期 2
·625-634
·
IF 3.241
Jieyu Wu,Rongfa Guan,Haizhi Huang,Zhenfeng Liu,Haitao Shen,Qile Xia
The instability of catechins (CT) is currently a challenge for their application in the food industry. This study explored whether or not the protective effects of liposome encapsulation on CT could enhance the role of CT as antioxidants in reducing nitrosamines (NAs) in traditional Chinese bacon (TCB). The samples were further characterized by the analysis of volatile compounds, color parameters, and texture profile during storage to assess the effects of catechin liposomes (CTL) on TCB. Results showed that the increase in NAs in fried TCB was strongly dependent on the storage time. CTL could reduce the production of NAs in fried TCB (40.45%) more strongly than CT (15.13%) after 49 days of storage. Higher phenol contents were found in CTL (1515.25 × 106 area unit (AU)) than those in control (1451.73 × 106 AU) and CT (1391.10 × 106 AU) TCB at the end of storage. The addition of antioxidants increased (p < 0.05) a* values in the following order: CTL > CT > control with mean values of 6.54, 5.09, and 3.92, respectively, after 49-day storage. Conversely, the addition of CTL decreased (p < 0.05) the hardness of TCB. Encapsulating CT in the liposomes can effectively reduce the NAs in TCB and positively affect its quality. This technique may guide the potential application of liposomes in the meat industry.
研究领域:
食品科学
·
生物学
·
营养学
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DOI
PubMed
高影响因子
FUEL
·
2025
·
IF 7.5
Hui Li,Jiankan Zhang,Fengqi Zhao,Xuefeng Huang
Optimizing the ignition and combustion characteristics of Al by fluorine-containing oxidizers have attracted significant interest. However, few of them dedicated to alleviate the incomplete combustion of Al in propellant. Herein, we demonstrated that the combustion of micron-Al in AP free nitramine-based propellants can be greatly enhanced by thin coating layer of PVDF, resulting decreased volume fraction of agglomerates exceeding the initial particle size and active Al content in condensed combustion products (CCPs). After extensive analysis from thermal reactivity, single particle ignition and observation of particles evolution from burning surface to flame zone, we propose that the combustion efficiency is promoted by the fragmentation of chain structured aluminum skeleton by gas recoil near burning surface, oxidation acceleration by diffusion of Al and oxidative gas through the cracks among the particle shell in the dark zone and the subsequent ejection of molten Al triggered by gasification of low boiling point AlF 3 in the flame zone. The findings in this work suggest that core–shell Al@PVDF has a great potential to be further used in the development of future highly energetic solid propellants.
研究领域:
材料科学
·
燃烧学
·
推进剂技术
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Xiaochao Duan,Xiaobin Liao,Jianfei Chen,Shuguang Xie,Huan Qi,Fei Li,Baoling Yuan
Disinfection is an indispensable process to inactivate pathogens , while unexpected disinfection by-products (DBPs) would also be formed between the reaction of residual disinfectants and microorganisms in the water distribution system (WDS). However, there are few studies referring to the formation of DBPs and DBPs-associated toxicity under various disinfection methods based on microorganisms in the real WDS. In addition, the main contributors of bacterial communities or components that generate DBPs are unclear. In this study, the formation of trihalomethanes (THMs), halo-acetic acids (HAAs), nitrosamines (NAs) from culturable microorganisms in pipeline network by ozonation(O 3 ), chlorination (Cl 2 ), chloramination (NH 2 Cl) and joint disinfection methods were compared, meanwhile, their calculated toxicities under different oxidation scenarios were also discussed. Moreover, 16S ribosomal ribonucleic acid (rRNA) gene sequencing was used to identify the main microbial communities . The results demonstrated that THMs and HAAs increased with increasing disinfectant dosages, while the quantity of NAs (mainly nitroso dimethylamine (NDMA)) was not significantly related to disinfectant dosages for each disinfection strategy. Chloroform (TCM) and dichloroacetic acid (DCAA) were the dominant THMs and HAAs species, respectively. NDMA existed in the samples before disinfections, which may due to the metabolic activity of microorganisms. Pre-O 3 increased THMs formation during subsequent Cl 2 and NH 2 Cl treatment. However, pre-O 3 effectively reduced HAAs produced by subsequent chlorination. O 3 /Cl 2 disinfection had the highest DBPs formation potential (DBPFP) (883.6 nM), while its calculated toxicity was similar to that in Cl 2 disinfection treatment. Pseudomonas was the most abundant bacterial genus in biofilm of WDS pipeline. This study can aid in an optimal disinfection strategy for water treatment plants to reduce the toxicity of DBPs caused by biomass in pipelines and ensure water quality safety.
研究领域:
环境科学
·
微生物学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）