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Sample records for chloramines

  1. Chloramine chemistry - web based application

    Science.gov (United States)

    Chlorine disinfection remains quite popular in the United States, but because of the Stage 1 and Stage 2 Disinfectants and Disinfection Byproducts Rules, many United States utilities now use combinations of chlorine and chloramines to avoid excessive regulated trihalomethane and ...

  2. Inactivation of Helicobacter pylori by Chloramination

    Science.gov (United States)

    Three strains of Helicobacter pylori (H. pylori) were studied to determine their resistance to chloramination. H. pylori is an organism listed on the U.S. Environmental Protection Agency’s (USEPA) Contaminant Control List (CCL). H. pylori was exposed to 2ppm of pre-formed monoc...

  3. Formation of organic chloramines during chlor(am)ination and UV/chlor(am)ination of algae organic matter in drinking water.

    Science.gov (United States)

    Zhang, Tian-Yang; Lin, Yi-Li; Xu, Bin; Cheng, Tuo; Xia, Sheng-Ji; Chu, Wen-Hai; Gao, Nai-Yun

    2016-10-15

    Surface water are frequently subjected to problems of algal blooms and release of algae organic matter (AOM) from the algae cells, which cause many water quality issues. This study investigated the formation of organic chloramines and nitrogenous disinfection by-products (N-DBPs) during chlor(am)ination and UV/chlor(am)ination of AOM in drinking water. AOM caused higher organic chloramine formation than humic acid and fulvic acid during chlor(am)ination. The formation of organic chloramines increased first and then decreased with the increase of free chlorine dosage, but kept increasing with the increase of NH2Cl dosage. During AOM chlorination, the formation of organic chloramines kept decreasing as the reaction time went by, and the maximum organic chloramine proportion (79.1%) in total chlorine occurred at 8 h. However, during AOM chloramination, the formation of organic chloramines increased first, decreased in the following and then increased again as the reaction time went by, and the maximum organic chloramine proportion (22.1%) in total chlorine occurred at 24 h. UV irradiation pretreatment did not effectively influence organic chloramine formation during AOM chlor(am)ination, but accelerated the degradation of organic chloramines during chloramination. Besides, UV pretreatment enhanced the formation of N-DBPs during the subsequent chlor(am)ination of AOM, especially dichloroacetonitrile.

  4. Chloramine-induced anaphylaxis while showering: a case report

    Directory of Open Access Journals (Sweden)

    D’Alò Simona

    2012-09-01

    Full Text Available Abstract Introduction Sodium-N-chlorine-p-toluene sulfonamide, commonly known as chloramine-T, is a derivative of chlorine which is widely used as a disinfectant. For many years, chloramine-T has been described as a cause of immediate-type hypersensitivity, especially with regard to asthma and rhinitis, and as a cause of occupational dermatoses in cleaning personnel in hospitals, although no anaphylactic reaction has yet been reported. Hence, to the best of our knowledge we present the first case of anaphylaxis to chloramine-T with evidence of specific immunoglobulin E antibodies. Case presentation We describe the case of a 25-year-old Caucasian woman who was in good health and with a negative history for atopy, including no respiratory symptoms of rhinitis or asthma, and with no professional exposure to chloramine-T. She, while showering, applied a chloramine-T solution to a skin area with folliculitis on her leg, and within a few minutes developed generalized urticaria and angioedema, followed by vomiting and collapse with loss of consciousness. A skin prick test with a chloramine-T solution at 10mg/mL concentration was positive, and specific immunoglobulin E to chloramine-T was quantified at a value of 2.9 optical density as measured by the enzyme allergosorbent test technique. Conclusion The strict cause-effect relationship and the results of the skin test and the in vitro test make certain the causative role of chloramine-T in this case of anaphylaxis. This suggests that chloramine-T, based on its wide use as a disinfectant, should be considered a possible cause in anaphylaxis of unknown origin.

  5. Chloramination of Organophosphorus Pesticides Found in Drinking Water Sources

    Science.gov (United States)

    The degradation of commonly detected organophosphorus (OP) pesticides, in drinking water sources, was investigated under simulated chloramination conditions. Due to monochloramine autodecomposition, it is difficult to observe the direct reaction of monochloramine with each OP pe...

  6. A Long-Term Study of the Microbial Community Structure in a Simulated Chloraminated Drinking Water Distribution System - abstract

    Science.gov (United States)

    Many US water treatment facilities use chloramination to limit regulated disinfectant by-product formation. However, chloramination has been shown to promote nitrifying bacteria, and 30 to 63% of water utilities using secondary chloramine disinfection experience nitrification ep...

  7. NDMA formation by chloramination of ranitidine: Kinetics and mechanism

    KAUST Repository

    Le Roux, Julien

    2012-10-16

    The kinetics of decomposition of the pharmaceutical ranitidine (a major precursor of NDMA) during chloramination was investigated and some decomposition byproducts were identified by using high performance liquid chromatography coupled with mass spectrometry (HPLC-MS). The reaction between monochloramine and ranitidine followed second order kinetics and was acid-catalyzed. Decomposition of ranitidine formed different byproducts depending on the applied monochloramine concentration. Most identified products were chlorinated and hydroxylated analogues of ranitidine. In excess of monochloramine, nucleophilic substitution between ranitidine and monochloramine led to byproducts that are critical intermediates involved in the formation of NDMA, for example, a carbocation formed from the decomposition of the methylfuran moiety of ranitidine. A complete mechanism is proposed to explain the high formation yield of NDMA from chloramination of ranitidine. These results are of great importance to understand the formation of NDMA by chloramination of tertiary amines. © 2012 American Chemical Society.

  8. Organic chloramines in drinking water: An assessment of formation, stability, reactivity and risk.

    Science.gov (United States)

    How, Zuo Tong; Linge, Kathryn L; Busetti, Francesco; Joll, Cynthia A

    2016-04-15

    Although organic chloramines are known to form during the disinfection of drinking water with chlorine, little information is currently available on their occurrence or toxicity. In a recent in vitro study, some organic chloramines (e.g. N-chloroglycine) were found to be cytotoxic and genotoxic even at micromolar concentrations. In this paper, the formation and stability of 21 different organic chloramines, from chlorination of simple amines and amino acids, were studied, and the competition between 20 amino acids during chlorination was also investigated. For comparison, chlorination of two amides was also conducted. The formation and degradation of selected organic chloramines were measured using either direct UV spectroscopic or colorimetric detection. Although cysteine, methionine and tryptophan were the most reactive amino acids towards chlorination, they did not form organic chloramines at the chlorine to precursor molar ratios that were tested. Only 6 out of the 21 organic chloramines formed had a half-life of more than 3 h, although this group included all organic chloramines formed from amines. A health risk assessment relating stability and reactivity data from this study to toxicity and precursor abundance data from the literature indicated that only N-chloroglycine is likely to be of concern due to its stability, toxicity and abundance in water. However, given the stability of organic chloramines formed from amines, more information about the toxicity and precursor abundance for these chloramines is desirable.

  9. Taurine chloramine protects RAW 264.7 macrophages against hydrogen peroxide-induced apoptosis by increasing antioxidants

    OpenAIRE

    Piao, Shuyu; Cha, Young-Nam; Kim, Chaekyun

    2011-01-01

    Taurine chloramine is the major chloramine generated in activated neutrophils via the reaction between the overproduced hypochlorous acid and the stored taurine. Taurine chloramine has anti-inflammatory and cytoprotective effects in inflamed tissues by inhibiting the production of inflammatory mediators. Taurine chloramine increases heme oxygenase activity and also protects against hydrogen peroxide (H2O2)-derived necrosis in macrophages. In this study, we examined further whether taurine chl...

  10. CYCLIC VOLTAMMETRY OF ORGANIC AND INORGANIC N-CHLORAMINES IN AQUEOUS SOLUTION

    Science.gov (United States)

    Aqueous solutions or organic and inorganic N-chloramines as well as hypochlorite were examined by cyclic voltammetry at DH 8 and in strong acid (pH<2) with platinum and glassy carbon electrodes. The inorganic N-chloramines were characterized in 1 M HC104. NHC12 is reduced at abou...

  11. Effect of X-ray Contrast Media, Chlorination, and Chloramination on Zebrafish Development

    Science.gov (United States)

    Effect of X-ray Contrast Media, Chlorination, and Chloramination on Zebrafish Development Little is known about the vertebrate developmental toxicity of chlorinated or chloraminated drinking water (DW), iodinated X-ray contrast media (ICM, a common contaminate of DW) or how the c...

  12. Relative Importance of Nitrite Oxidation by Hypochlorous Acid under Chloramination Conditions

    Science.gov (United States)

    The importance of nitrite’s oxidation by tree chlorine under chloramination conditions was evaluated using batch kinetic experiments and a chloramine model implemented into the computer program AWUASIM. The experimental data was best represented with the inclusion of a reaction b...

  13. EFFECTS OF CHLORAMINATION AND SITE SPECIFIC ISSUES ON NANOFILTRATION FLUX LOSS AND FOULANT CHARACTERISTICS

    Science.gov (United States)

    The presence of chloramines or free ammonium ion was found to have little effect on the final specific flux and fouling cake-layer characteristics of nanofiltration membrances fed pretreated Little Miami Aquifer water. The system fed chloraminated water had the greatest amount o...

  14. Reaction of protein chloramines with DNA and nucleosides

    DEFF Research Database (Denmark)

    Hawkins, Clare L; Pattison, David I; Davies, Michael Jonathan

    2002-01-01

    . The role of HOCl in the oxidation of isolated proteins, DNA and their components has been investigated extensively, but little work has been performed on the protein-DNA (nucleosome) complexes present in eukaryotic cell nuclei. Neither the selectivity of damage in such complexes nor the possibility...... of transfer of damage from the protein to DNA or vice versa, has been studied. In the present study, kinetic modelling has been employed to predict that reaction occurs predominantly with the protein and not with the DNA in the nucleosome, using molar HOCl excesses of up to 200-fold. With 50-200-fold excesses...... for HOCl in the nucleosome. Furthermore, the resulting protein chloramines and the radicals derived from them may act as contributing agents in HOCl-mediated DNA oxidation....

  15. Preparation and evaluation of radio labelled recombinant human interleukin 2 by improved chloramine T method

    International Nuclear Information System (INIS)

    Iodination by improved chloramine T method was investigated. Iodine was activated with very small quantity of chloramine T (21 fold excess to iodine in molar ratio) and then recombinant interleukin-2 (rIL-2) was added to the mixture. Characteristics of the labelled rIL-2 after purification by reversed-phase HPLC was superior to those by usual chloramine T method or lactoperoxidase method. The specific activity was 0.74-1.11 MBq/μg and the immunoreactivity, biological activity and binding ability to rIL-2 receptors were similar to the intrinsic rIL-2. The improved chloramine T method is useful for iodination of unstable peptides and proteins. (author)

  16. Preparation and evaluation of radio labelled recombinant human interleukin 2 by improved chloramine T method

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masahiro; Kominami, Goro; Kono, Masao (Shionogi and Co. Ltd., Osaka (Japan). Research Lab.)

    1991-03-01

    Iodination by improved chloramine T method was investigated. Iodine was activated with very small quantity of chloramine T (21 fold excess to iodine in molar ratio) and then recombinant interleukin-2 (rIL-2) was added to the mixture. Characteristics of the labelled rIL-2 after purification by reversed-phase HPLC was superior to those by usual chloramine T method or lactoperoxidase method. The specific activity was 0.74-1.11 MBq/{mu}g and the immunoreactivity, biological activity and binding ability to rIL-2 receptors were similar to the intrinsic rIL-2. The improved chloramine T method is useful for iodination of unstable peptides and proteins. (author).

  17. Effects of operating conditions on trihalomethanes formation and speciation during chloramination in reclaimed water.

    Science.gov (United States)

    Wang, Fang; Gao, Baoyu; Ma, Defang; Li, Ruihua; Sun, Shenglei; Yue, Qinyan; Wang, Yan; Li, Qian

    2016-01-01

    In this study, a hybrid powdered activated carbon-membrane bioreactor (PAC-MBR) system was used to treat municipal wastewater in northern China intended for recycle. In order to control microbiological hazards in PAC-MBR effluent, chloramine was chosen as the disinfectant which could reduce the disinfection by-product yields. Effects of reaction time, chloramines dose, pH value, and bromide ion concentration on trihalomethanes (THMs) formation and speciation during chloramination of the reclaimed effluent were investigated. Study results indicated that the yield of total THMs (TTHM) increased at higher reaction time and chloramines dose. The trend of growth showed that slow reacting precursors were the main components of dissolved organic matter (DOM) in PAC-MBR effluent. THMs formation potential of PAC-MBR effluent achieved the maximum at chloramines dosage of 20 mg/L. Meanwhile, THMs formation was enhanced evidently under alkaline conditions. The yields of THMs species were in following order: CHCl3 > CHBrCl2 > CHBr2Cl > CHBr3, although in different reaction time, chloramines dose, and pH value. Furthermore, the formation of Br-THMs was promoted by the increasing concentration of bromide ion. PMID:26377970

  18. MECANISME DE FORMATION DES NITROSAMINES ET SOUS-PRODUITS HALOGENES LORS DE LA CHLORAMINATION DE CONTAMINANTS ORGANIQUES AZOTES EMERGENTS

    OpenAIRE

    Le Roux, Julien

    2011-01-01

    The aim of this study was to investigate the mechanisms of formation of N nitrosodimethylamine (NDMA) by chloramination of nitrogenous organic contaminants. First, the formation of NDMA was demonstrated by chloramination of several anthropogenic compounds such as pharmaceuticals and pesticides. Especially, the pharmaceutical ranitidine was the most important precursor of NDMA. NDMA formation by chloramination of ranitidine reaches a maximum around pH 8, and is not favored by the presence of d...

  19. Modeling the formation of TOCl, TOBr and TOI during chlor(am)ination of drinking water.

    Science.gov (United States)

    Zhu, Xiaohu; Zhang, Xiangru

    2016-06-01

    The use of chlorine and chloramines in drinking water disinfection may produce innumerable halogenated disinfection byproducts (DBPs). Because of the impossibility of measuring the concentration and evaluating the toxicity of each individual halogenated DBP in a water sample, total organic halogen (TOX) as a collective parameter and a toxicity indicator for all the halogenated DBPs has been gaining popularity in recent years. TOX can be divided into total organic chlorine (TOCl), total organic bromine (TOBr), and total organic iodine (TOI). Previously, the authors' group studied the formation kinetics of TOCl and TOBr in chlor(am)ination using two models. In this study, we further explored the formation kinetics of TOI as well as TOCl and TOBr during chlor(am)ination by carefully selecting a series of iodine-related reactions and incorporating them into the two kinetic models. The models well predicted the levels of TOCl, TOBr, TOI, and total chlorine residual during chlorination and chloramination of simulated raw waters. According to the modeling results, 57.1-73.6% of the total generated iodinated DBPs in chlorination was converted to their chlorinated and brominated analogues by the substitution with hypochlorous acid and hypobromous acid; while in chloramination, with the presence of excessive monochloramine, the formed hypoiodous acid might react with monochloramine to form an iodine-substituted intermediate (proposed as chloroiodamine), which was responsible for 41.4-49.8% of the total generated iodinated DBPs, and meantime 51.9-52.6% of the total generated iodinated DBPs underwent deiodination via the base-catalyzed hydrolysis. The models were successfully applied in determining the lag time between the dosages of chlorine and ammonia, a challenging issue in chlorine-chloramine sequential treatment. This study provided important insights into kinetic reactions that control the formation of overall halogenated DBPs in chlor(am)ination.

  20. Modeling the formation of TOCl, TOBr and TOI during chlor(am)ination of drinking water.

    Science.gov (United States)

    Zhu, Xiaohu; Zhang, Xiangru

    2016-06-01

    The use of chlorine and chloramines in drinking water disinfection may produce innumerable halogenated disinfection byproducts (DBPs). Because of the impossibility of measuring the concentration and evaluating the toxicity of each individual halogenated DBP in a water sample, total organic halogen (TOX) as a collective parameter and a toxicity indicator for all the halogenated DBPs has been gaining popularity in recent years. TOX can be divided into total organic chlorine (TOCl), total organic bromine (TOBr), and total organic iodine (TOI). Previously, the authors' group studied the formation kinetics of TOCl and TOBr in chlor(am)ination using two models. In this study, we further explored the formation kinetics of TOI as well as TOCl and TOBr during chlor(am)ination by carefully selecting a series of iodine-related reactions and incorporating them into the two kinetic models. The models well predicted the levels of TOCl, TOBr, TOI, and total chlorine residual during chlorination and chloramination of simulated raw waters. According to the modeling results, 57.1-73.6% of the total generated iodinated DBPs in chlorination was converted to their chlorinated and brominated analogues by the substitution with hypochlorous acid and hypobromous acid; while in chloramination, with the presence of excessive monochloramine, the formed hypoiodous acid might react with monochloramine to form an iodine-substituted intermediate (proposed as chloroiodamine), which was responsible for 41.4-49.8% of the total generated iodinated DBPs, and meantime 51.9-52.6% of the total generated iodinated DBPs underwent deiodination via the base-catalyzed hydrolysis. The models were successfully applied in determining the lag time between the dosages of chlorine and ammonia, a challenging issue in chlorine-chloramine sequential treatment. This study provided important insights into kinetic reactions that control the formation of overall halogenated DBPs in chlor(am)ination. PMID:27038586

  1. 40 CFR 141.535 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Science.gov (United States)

    2010-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.535 Section 141.535 Protection of Environment... § 141.535 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone, or chlorine dioxide for primary disinfection, you must...

  2. 40 CFR 141.544 - What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?

    Science.gov (United States)

    2010-07-01

    ..., ozone, or chlorine dioxide for primary disinfection? 141.544 Section 141.544 Protection of Environment... Benchmark § 141.544 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection? If your system uses chloramines, ozone or chlorine dioxide for primary disinfection your system...

  3. [Formation of Disinfection By-Products During Chlor(am)ination of Danjiangkou Reservoir Water and Comparison of Disinfection Processes].

    Science.gov (United States)

    Zhang, Min-sheng; Xu, Bin; Zhang, Tian-yang; Cheng, Tuo; Xia, Sheng-ji; Chu, Wen-hai

    2015-09-01

    This study discussed the formation of volatile carbonaceous disinfection by-products (DBPs) and nitrogenous DBPs during chlor(am) ination of Danjingkou Reservoir water which was the source of the Middle Route Project of South-to-North Water Diversion Project. The effects of disinfection methods, disinfectant dosage, reaction time, pH values and bromide ion concentration were investigated. And the disinfection parameters were optimized. Four DBPs, including chloroform (CF), bromodichloromethane (BDCM), dichloroacetonitrile(DCAN) and trichloronitromethane(TCNM), were observed during the chlorination. But only CF and TCNM were detected during the chloramination of water. The disinfection by-product (DBP) concentration from chlorination is 7. 5 times higher than that from chloramination, and the yield of DBPs from short time chlorination then chloramination is in between the first two methods. All kinds of DBPs detected increased with the dosage of increasing chlorine, but the increases slowed down when the dosage was higher than 2 mg . L -1. The formation of CF varied a little as the dosage of chloramine increasing. TCNM was detected when the chloramine dosage was greater than 2 mg . L -1. As reaction time going on, chlorine decayed much faster than chloramine, while DBP formation under chlorination was faster than that of chloramination. THM produced by chlorine increased with the increasing pH, while chloramination showed no obvious changes. As the bromide ion increasing, the species of DBPs transformed from chlorinated DBPs to brominated ones, and the total yield of DBPs increased during both chlorination and chloramination, but the former one was obviously more than that of the latter one. In order to reduce the risk of DBP formation, the chloramination is suggested in the treatment of water from Danjiangkou Reservoir. And if chlorination is applied, the disinfectant dosage should be controlled seriously.

  4. Impact of Chloramination on the Development of Laboratory-Grown Biofilms Fed with Filter-Pretreated Groundwater

    KAUST Repository

    Ling, Fangqiong

    2013-01-01

    This study evaluated the continuous impact of monochloramine disinfection on laboratory-grown biofilms through the characterization of biofilm architecture and microbial community structure. Biofilm development and disinfection were achieved using CDC (Centers for Disease Control and Prevention) biofilm reactor systems with polyvinyl chloride (PVC) coupons as the substratum and sand filter-pretreated groundwater as the source of microbial seeding and growth nutrient. After 2 weeks of growth, the biofilms were subjected to chloramination for 8 more weeks at concentrations of 7.5±1.4 to 9.1±0.4 mg Cl2 L-1. Control reactors received no disinfection during the development of biofilms. Confocal laser scanning microscopy and image analysis indicated that chloramination could lead to 81.4-83.5% and 86.3-95.6% reduction in biofilm biomass and thickness, respectively, but could not eliminate biofilm growth. 16S rRNA gene terminal restriction fragment length polymorphism analysis indicated that microbial community structures between chloraminated and non-chloraminated biofilms exhibited different successional trends. 16S rRNA gene pyrosequencing analysis further revealed that chloramination could select members of Actinobacteria and Acidobacteria as the dominant populations, whereas natural development leads to the selection of members of Nitrospira and Bacteroidetes as dominant biofilm populations. Overall, chloramination treatment could alter the growth of multi-species biofilms on the PVC surface, shape the biofilm architecture, and select a certain microbial community that can survive or proliferate under chloramination.

  5. Pyridinium hydrobromide perbromide: a versatile catalyst for aziridination of olefins using Chloramine-T.

    Science.gov (United States)

    Ali, S I; Nikalje, M D; Sudalai, A

    1999-09-01

    [reaction: see text] Pyridinium hydrobromide perbromide (Py x HBr3) catalyzes effectively the aziridination of electron-deficient as well as electron-rich olefins using Chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide) as a nitrogen source to afford the corresponding aziridines in moderate to good yields. PMID:16118868

  6. OCCURRENCE AND TOXICITY OF IODO-ACID AND IODO-THM DBPS IN CHLORAMINATED DRINKING WATER

    Science.gov (United States)

    As part of a recent Nationwide Disinfection By-Product (DBP) Occurrence Study, iodo-acids were identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid, bromoiodoacetic acid, (E)-3-bromo-3-iodo-prope...

  7. OCCURRENCE AND TOXICITY OF IODO-ACID DISINFECTION BY-PRODUCTS IN CHLORAMINATED DRINKING WATER

    Science.gov (United States)

    As part of a recent Nationwide Disinfection By-Product (DBP) Occurrence Study, iodo-acids were identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid (IAA), bromoiodoacetic acid, (E)-3-bromo-3-iodo...

  8. OCCURRENCE OF IODO-ACID AND IODO-THM DBPS IN U. S. CHLORAMINATED DRINKING WATERS

    Science.gov (United States)

    Iodo-acids were recently identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid (IAA), bromoiodoacetic acid, (E)-3-bromo-3-iodo-propenoic acid, (Z)-3-bromo-3-iodo-propenoic acid, and (E)-2-iodo-3...

  9. Microbial Community Dynamics of a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system (i.e. loop). The loop (BW-AB-I) received chlorinated municipal water (BW-C) amended with ammonia (2mg/L monochloramine). After six years of continuous operation, the operational ...

  10. Dichloroacetonitrile and dichloroacetamide can form independently during chlorination and chloramination of drinking waters, model organic matters, and wastewater effluents.

    Science.gov (United States)

    Huang, Huang; Wu, Qian-Yuan; Hu, Hong-Ying; Mitch, William A

    2012-10-01

    The increasing usage of organic nitrogen-rich wastewater- or algal-impacted waters, and chloramines for secondary disinfection, raises concerns regarding the formation of haloacetonitriles, haloacetamides and other nitrogenous disinfection byproducts (N-DBPs). Previous research obtained contradictory results regarding the relative importance of chlorination or chloramination for promoting these byproducts, but applied chlorine and chloramines at different doses and exposure periods. Additionally, mechanistic work, mostly using model precursors, suggested that haloacetonitrile and haloacetamide formation should be correlated because hydrolysis of haloacetonitriles forms haloacetamides. In this work, the formation of dichloroacetonitrile (DCAN) and dichloroacetamide (DCAcAm) were compared across a range of chlorine and chloramine exposures for drinking waters, wastewater effluents, algal extracellular polymeric substances (EPS), NOM isolates and model precursors. While chlorination favored formation of DCAN over DCAcAm, chloramination nearly always formed more DCAcAm than DCAN, suggesting the existence of haloacetamide formation pathways that are independent of the hydrolysis of haloacetonitriles. Experiments with asparagine as a model precursor also suggested DCAcAm formation without a DCAN intermediate. Application of (15)N-labeled monochloramine indicated initial rapid formation of both DCAN and DCAcAm by pathways where the nitrogen originated from organic nitrogen precursors. However, slower formation occurred by pathways involving chloramine incorporation into organic precursors. While wastewater effluents and algal EPS tended to be more potent precursors for DCAN during chlorination, humic materials were more potent precursors for DCAcAm during chlorination and for both DCAN and DCAcAm during chloramination. These results suggest that, rather than considering haloacetamides as haloacetonitrile hydrolysis products, they should be treated as a separate N

  11. Effects of ozone pretreatment on the formation of disinfection by-products and its associated bromine substitution factors upon chlorination/chloramination of Tai Lake water.

    Science.gov (United States)

    Wang, Fangyuan; Ruan, Mengyong; Lin, Hongjun; Zhang, Yu; Hong, Huachang; Zhou, Xiaoling

    2014-03-15

    This study investigated the effects of preozonation on disinfection by-products (DBPs) formation during chlorination and chloramination of the water collected from Tai Lake. Results showed that the high ozone dose (0.6-1.0 mg O₃/mg DOC) pretreatment reduced the yields of trihaloacetic acids (reduced 62-63% in chlorination), dihaloacetonitriles (reduced 53-55% and 14-26% in chlorination and chloramination, respectively) and trihaomethanes (reduced 19% in chloramination), but markedly increased the formation of halonitromethanes (increased 4.7-5.6 times in chlorination and 2.1-2.7 times in chloramination), haloketones (increased 4.8-7.1 times in chlorination and 2.5-2.9 times in chloramination) and dihaloacetic acids (increased 1.5-2.4 times in chlorination and 0.3-0.6 times in chloramination). Thus the high ozone dose pretreatment should be avoided during chlorination/chloramination of Tai Lake water. Also, chloramination (with and without preozonation) produced much lower DBPs yields as compared with chlorination (with and without preozonation), indicating that chloramine was a better choice to control the DBPs yields. Further analysis also revealed that the bromine substitution factors (BSFs) of DBPs varied with disinfection mode. In chlorinamination, the BSFs generally showed a decrease trend with the ozone dose, yet in chlorination, the BSFs mostly exhibited first an increase and then a decrease trend. Moreover, the BSFs of DBPs in chloramination (with or without preozonation) were dominantly lower than those in chlorination (with or without preozonation).

  12. Simulations and Experiments Reveal the Relative Significance of the Free Chlorine/Nitrite Reaction in Chloraminated Systems

    Science.gov (United States)

    Nitrification can be a problem in distribution systems where chloramines are used as secondary disinfectants. A very rapid monochloramine residual loss is often associated with the onset of nitrification. During nitrification, ammonia-oxidizing bacteria biologically oxidize fre...

  13. Simulations and Experiments Reveal the Relative Significance of the Free Chlorine/Nitrite Reaction in Chloraminated Systems - slides

    Science.gov (United States)

    Nitrification can be a problem in distribution systems where chloramines are used as secondary disinfectants. A very rapid monochloramine residual loss is often associated with the onset of nitrification. During nitrification, ammonia-oxidizing bacteria biologically oxidize fre...

  14. Comparison of Microbial Communities in a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system. After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The study was organized ...

  15. Draft Genome Sequences of Six Mycobacterium immunogenum, Strains Obtained from a Chloraminated Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome sequences of six Mycobacterium immunogenum isolated from a chloraminated drinking water distribution system simulator subjected to changes in operational parameters. M. immunogenum, a rapidly growing mycobacteria previously reported as the cause of hyp...

  16. Survival of cool and warm freshwater fish following chloramine-T exposure

    Science.gov (United States)

    Gaikowski, M.P.; Larson, W.J.; Gingerich, W.H.

    2008-01-01

    Chloramine-T is presently available in the USA to control mortalities associated with bacterial gill disease or external columnaris only through an Investigational New Animal Drug Permit authorized by the US Food and Drug Administration (FDA). Its US approval hinges on FDA's acceptance of several key data, including those describing animal safety. Chloramine-T is presently applied in US aquaculture, by permit only, once daily on consecutive or alternate days for 1??h at 10 to 20??mg/L to control mortalities associated with bacterial gill disease or external columnaris. Our objective was to determine the safety of chloramine-T bath exposures at multiples of the proposed maximum treatment concentration (i.e., 0, 20, 60, 100, and 200??mg/L) administered on four consecutive days at 20????C to lake sturgeon Acipenser fulvescens, northern pike Esox lucius, and walleye Sander vitreum, or at 27????C to channel catfish Ictalurus punctatus, and largemouth bass Micropterus salmoides. All fish were tested as five to eight week old fry except for walleye and channel catfish which were tested as both fry and fingerling (fingerlings were at least four weeks older than the fry tested). Walleye and channel catfish were selected to evaluate the effects of life stage (fry vs. fingerling), temperature (walleye - 15, 20, or 25????C; channel catfish - 22, 27, or 32????C), exposure duration (60 vs. 180??min), and water chemistry (walleye only - reconstituted soft water vs. well water). Except for channel catfish fry, survival was significantly reduced only when fish were treated at 100 or 200??mg/L. Channel catfish fry survival was significantly reduced when exposed at 60??mg/L for 180??min at 27????C. Based on our mortality data, chloramine-T administered once daily for 60??min on four consecutive days at concentrations of up to 20??mg/L is not likely to adversely affect survival of cool or warmwater fish cultured in freshwater. Crown Copyright ?? 2007.

  17. Chloramination of nitrogenous contaminants (pharmaceuticals and pesticides): NDMA and halogenated DBPs formation

    KAUST Repository

    Le Roux, Julien

    2011-05-01

    Disinfection with chloramines is often used to reduce the production of regulated disinfection by-products (DBPs) such as trihalomethanes (THMs) and haloacetic acids (HAAs). However, chloramination can lead to the formation of N-nitrosamines, including N-nitrosodimethylamine (NDMA), a probable human carcinogen. Previous research used dimethylamine (DMA) as a model precursor of NDMA, but certain widely used tertiary dimethylamines (e.g. the pharmaceutical ranitidine) show much higher conversion rates to NDMA than DMA. This study investigates the NDMA formation potential of several tertiary amines including pharmaceuticals and herbicides. The reactivity of these molecules with monochloramine (NH2Cl) is studied through the formation of NDMA, and other halogenated DBPs such as haloacetonitriles (HANs) and AOX (Adsorbable Organic Halides). Several compounds investigated formed NDMA in greater amounts than DMA, revealing the importance of structural characteristics of tertiary amines for NDMA formation. Among these compounds, the pharmaceutical ranitidine showed the highest molar conversion to NDMA. The pH and dissolved oxygen content of the solution were found to play a major role for the formation of NDMA from ranitidine. NDMA was formed in higher amounts at pH around pH 8 and a lower concentration of dissolved oxygen dramatically decreased NDMA yields. These findings seem to indicate that dichloramine (NHCl2) is not the major oxidant involved in the formation of NDMA from ranitidine, results in contradiction with the reaction mechanisms proposed in the literature. Dissolved oxygen was also found to influence the formation of other oxygen-containing DBPs (i.e. trichloronitromethane and haloketones). The results of this study identify several anthropogenic precursors of NDMA, indicating that chloramination of waters impacted by these tertiary amines could lead to the formation of significant amounts of NDMA and other non-regulated DBPs of potential health concern (e

  18. Radioiodination of interleukin 2 to high specific activities by the vapor-phase chloramine T method

    International Nuclear Information System (INIS)

    Recombinant human interleukin 2 (IL-2) was radioiodinated utilizing the vapor phase chloramine T method of iodination. The method is rapid, reproducible, and allows the efficient radioiodination of IL-2 to specific activities higher than those previously attained with full retention of biological activity. IL-2 radioiodinated by this method binds with high affinity to receptors present on phytohemagglutinin-stimulated peripheral blood lymphocytes and should be useful for the study of receptor structure and function

  19. Characterization of unknown iodinated disinfection byproducts during chlorination/chloramination using ultrahigh resolution mass spectrometry.

    Science.gov (United States)

    Wang, Xin; Wang, Juan; Zhang, Yahe; Shi, Quan; Zhang, Haifeng; Zhang, Yu; Yang, Min

    2016-06-01

    Iodinated disinfection byproducts (I-DBPs), formed from the reaction of disinfectant(s) with organic matter in the presence of iodide in raw water, have recently been focused because of their more cytotoxic and genotoxic properties than their chlorinated or brominated analogues. To date, only a few I-DBPs in drinking water have been identified. In this study, C18 solid phase extraction coupled with electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown I-DBPs in chloraminated/chlorinated water spiked with iodide and humic substances. In total, 178 formulas for one-iodine-containing products, 13 formulas for two-iodine-containing products, and 15 formulas for one-chlorine and one-iodine-containing products were detected in the chloraminated water sample, while only 9 formulas for one-iodine-containing products and 6 formulas for one-chlorine and one-iodine-containing products were found in the chlorinated water sample. Most I-DBPs have corresponding chlorine-containing analogues with identical CHO compositions. As indicated by the modified aromaticity index (AImod), in the C18 extracts, more than 68% of the I-DBPs have aromatic structures or polycyclic aromatic structures. This result demonstrates that the use of chloramination as an alternative disinfection method may lead to the formation of abundant species of I-DBPs in the presence of iodide. Thus, the suitability of adopting chloramination as an alternative disinfection method should be reevaluated, particularly when iodide is present in raw water.

  20. Using chloramine as a coagulant aid in enhancing coagulation of Yellow River water in China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Considering that contaminated raw water mostly contains high Ammonia-N and a majority of water treatment plants use prechlorination process in China, efficiency of chloramines as a coagulant aid in enhancing coagulation was investigated by Jar stirring and pilot-scale tests, using Yellow River water containing high concentration of natural organic matters (NOM) and bromide in winter. The jar tests results showed that, compared with no preoxidation, preformed chloramine apparently decreased the turbidity of settled and filtered water with low dosage (2.0 mg/L), and the aid-coagulation efficiency was further enhanced with the increase of chlorine (Cl2) to Ammonia-N (N) ratio. Pilot-scale studies indicated that, in comparison to the case without preoxidation, the turbidity removal efficiency of flotation and filtration effluent water was significantly improved, the particle counts of filtered water were decreased 63.4%, the average rate of filter head loss was reduced 18.2%, and filter run time was prolonged 15.7%. Therefore, chloramine preoxidation may substantially enhance the particle separation efficiency.

  1. Formation and cytotoxicity of a new disinfection by-product (DBP) phenazine by chloramination of water containing diphenylamine

    Institute of Scientific and Technical Information of China (English)

    Wenjun Zhou; Linjie Lou; Lifang Zhu; Zhimin Li; Lizhong Zhu

    2012-01-01

    Disinfection by-products (DBPs) in drinking water have caused worldwide concern due to their potential earcinogenic effects.The formation of phenazine from diphenylamine (DPhA) chloramination was studied and its cytotoxicities for two human cancer cells were also investigated.Phenazine was detected synchronously with the consumption of DPhA by chloramination,which further confirmed that the new DBP phenazine can be produced along with N-nitrosodiphenylamine (NDPhA) from DPhA chloramination.The formation of phenazine had a maximum molar yield with solution pH increasing from 5.0 to 9.0,with phernazine as the main product for DPhA chloramination at lower pH,but higher pH favored the formation of NDPhA.Thus,solution pH is the key factor in controlling the formation of phenazine and NDPhA.Both the initial DPhA and chloramine concentrations did not show a significant effect on the molar yields of phenazine,although increasing the chloramine concentration could speed up the reacdon rate of DPhA with chloramines.The cytotoxicity assays showed that phenazine had significant cell-specific toxicity towards T24 (bladder cancer cell lines) and HepG2 (hepatic tumor cell lines) cells with IC50 values of 0.50 and 2.04 mmol/L,respectively,and T24 ceils being more sensitive to phenazine than HepG2 ceils.The IC50 values of phenazine,DPhA,and NDPhA for T24 cells were of the same order of magnitude and the cytotoxicity of phenazine for T24 cells was slightly lower than that of NDPhA (IC50,0.16 mmol/L),suggesting that phenazine in drinking water may have an adverse effect on human health.

  2. Acid-base and ionic fluxes in rainbow trout (Oncorhynchus mykiss) during exposure to chloramine-T

    Energy Technology Data Exchange (ETDEWEB)

    Powell, M.D.; Perry, S.F. [Department of Biology, University of Ottawa, 30 Marie Curie Ottawa, Ontario, K1N 6N5 (Canada)

    1998-09-01

    The effects of chloramine-T and its degradation products, sodium hypochlorite (NaOCl) and para-toluenesulphonamide (pTSA), on whole body acid-base and branchial and renal ion (Na{sup +}and Cl{sup -}) fluxes were examined in rainbow trout (Oncorhynchus mykiss). Exposure to chloramine-T (3.5 h, 18 mg l{sup -1}) resulted in increases in plasma total CO{sub 2} but no coincident rise in P{sub a}CO{sub 2} or reduction in blood pH. Exposure of fish to 2, 9 or 18 mg l{sup -1} chloramine-T (3.5 h duration) resulted in a reduction in net acid uptake suggesting the development of a metabolic alkalosis. Exposure to the chloramine-T breakdown product pTSA (dissolved in DMSO) resulted in increased net acid uptake (decreased acid excretion) suggesting a metabolic acidosis. Whole body ion fluxes demonstrated increases in the losses of both Na{sup +}and Cl{sup -} with chloramine-T, NaOCl and pTSA. However, the effect of DMSO alone could not be isolated. Confirmatory studies using fish in which the urinary bladder (to allow collection of urine) and dorsal aorta (to allow injection of [{sup 14}C]polyethylene glycol 4000 ([{sup 14}C]PEG), an extracellular fluid marker) were catheterised, revealed that changes in whole body ion fluxes during chloramine-T exposure could not be explained by increased renal efflux through urine flow, glomerular filtration or renal clearance. Branchial effluxes of [{sup 14}C]PEG were not significantly affected by chloramine-T exposure suggesting that the changes in whole body ionic fluxes were caused by transcellular rather than paracellular processes. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. [Genotoxicity of drinking water during chlorine and chloramine disinfection and the influence of disinfection conditions using the umu-test].

    Science.gov (United States)

    Liu, Qing; Zhang, Li-Ping; Liu, Wen-Jun; Nie, Xue-Biao; Zhang, Su-Xia; Zhang, Shun

    2010-01-01

    In this study, the effects of disinfectant dosage, reaction time and the ratio of Cl2 to N of disinfectant on genotoxicity of effluent of ozone-biological activated carbon (O3-BAC) during chlorine or chloramine disinfection were investigated using umu-test. It was found that, the genotoxicity of effluent of O3-BAC before disinfection ranged from 20-70 ng/L, and it increased after disinfection by chlorine or chloramines. With the same reaction time(24 h), genotoxicity after chlorination (40-95 ng/L) was higher than that after chloramination (20-40 ng/L) under same initial dosage. For chlorination, with initial dosage increasing from 0 mg/L to 10 mg/L, genotoxicity increased firstly, and got the maximum value at about 0.5-1 mg/L dosage, then decreased and got the minimum value at about 3-5 mg/L dosage, and finally increased again. For chloramination, genotoxicity didn't change that much. With the dosage of 3 mg/L and reaction time increasing from 0 h to 72 h, no matter for chlorine or chloramines disinfection, genotoxicity of effluent of O3-BAC both increased firstly, and got the maximum value at about 2 h, then decreased and got the minimum value at about 18 h, and finally increased again, and genotoxicity after chlorine disinfection (83-120 ng/L) was higher than that after chloramines disinfection (20-62 ng/L) under same reaction time. Further more, effects of the different ratios of Cl2 to N of disinfectant on genotoxicity of effluent of O3-BAC were also studied. Results of this study demonstrate that under test conditions, chloramine disinfection is safer than chlorine disinfection in the aspect of genotoxicity for drinking water, and the changes of genotoxicity are different from those of total HAAs.

  4. Role of NOM molecular size on iodo-trihalomethane formation during chlorination and chloramination.

    Science.gov (United States)

    Zhang, Jie; Chen, Dan-Dan; Li, Lei; Li, Wen-Wei; Mu, Yang; Yu, Han-Qing

    2016-10-01

    Natural organic matter (NOM) is the major precursor for the generation of disinfection byproducts (DBPs) during disinfection, but the role of the NOM molecular size on the formation of iodinated DBPs (I-DBPs) is still unclear. The objective of this study was to evaluate the function of the NOM molecular size on the formation of iodo-trihalomethane (I-THMs) during chlorination and chloramination. Humic acid was adopted as the NOM matrix and fractionated into four molecular weight (MW) groups. Various parameters, including iodide, bromide, NOM concentrations, pH, and pre-chlorination time, were investigated for each MW fraction. During chlorination, high MW fractions (i.e., MW > 100 K Da and 50 K < MW < K00 K Da) produced more I-THMs compared with small MW fractions (i.e., MW < 3 K Da and 3 K < MW < 50 K Da). With the increase in the I(-) or NOM concentration, the formation of I-THMs increased for small MW fractions, while a slight reduction occurred for high MW fractions during chlorination. Higher pH resulted in more I-THM formation for small MW fractions, while the opposite was true for high MW fractions during chlorination. Compared to small MW fractions, bromide was relatively more reactive with high MW fractions in the formation of I-THMs during chlorination. During chloramination, the I-THM yields decreased with the increasing NOM concentration for high MW fractions. The concentration of bromine-containing I-THMs decreased with increasing pH for all MW fractions during chloramination. Additionally, with the prolongation of pre-chlorination time, the total amount of I-THMs decreased remarkably for MWs higher than 3 K Da, while a slight change for MW lower than 3 K Da occurred during chloramination. The results from this study suggest that the molecular weight of the NOM plays an important role in the formation of I-THMs during chlorination and chloramination. PMID:27423047

  5. The role of aromatic precursors in the formation of haloacetamides by chloramination of dissolved organic matter.

    Science.gov (United States)

    Le Roux, Julien; Nihemaiti, Maolida; Croué, Jean-Philippe

    2016-01-01

    Water treatment utilities are diversifying their water sources and often rely on waters enriched in nitrogen-containing compounds (e.g., ammonia, organic nitrogen such as amino acids). The disinfection of waters exhibiting high levels of nitrogen has been associated with the formation of nitrogenous disinfection byproducts (N-DBPs) such as haloacetonitriles (HANs) and haloacetamides (HAcAms). While the potential precursors of HANs have been extensively studied, only few investigations are available regarding the nature of HAcAm precursors. Previous research has suggested that HAcAms are hydrolysis products of HANs. Nevertheless, it has been recently suggested that HAcAms can be formed independently, especially during chloramination of humic substances. When used as a disinfectant, monochloramine can also be a source of nitrogen for N-DBPs. This study investigated the role of aromatic organic matter in the formation of N-DBPs (HAcAms and HANs) upon chloramination. Formation kinetics were performed from various fractions of organic matter isolated from surface waters or treated wastewater effluents. Experiments were conducted with (15)N-labeled monochloramine ((15)NH2Cl) to trace the origin of nitrogen. N-DBP formation showed a two-step profile: (1) a rapid formation following second-order reaction kinetics and incorporating nitrogen atom originating from the organic matrix (e.g., amine groups); and (2) a slower and linear increase correlated with exposure to chloramines, incorporating inorganic nitrogen ((15)N) from (15)NH2Cl into aromatic moieties. Organic matter isolates showing high aromatic character (i.e., high SUVA) exhibited high reactivity characterized by a major incorporation of (15)N in N-DBPs. A significantly lower incorporation was observed for low-aromatic-content organic matter. (15)N-DCAcAm and (15)N-DCAN formations exhibited a linear correlation, suggesting a similar behavior of (15)N incorporation as SUVA increases. Chloramination of aromatic model

  6. The role of aromatic precursors in the formation of haloacetamides by chloramination of dissolved organic matter

    KAUST Repository

    Le Roux, Julien

    2015-10-21

    Water treatment utilities are diversifying their water sources and often rely on waters enriched in nitrogen-containing compounds (e.g., ammonia, organic nitrogen such as amino acids). The disinfection of waters exhibiting high levels of nitrogen has been associated with the formation of nitrogenous disinfection byproducts (N-DBPs) such as haloacetonitriles (HANs) and haloacetamides (HAcAms). While the potential precursors of HANs have been extensively studied, only few investigations are available regarding the nature of HAcAm precursors. Previous research has suggested that HAcAms are hydrolysis products of HANs. Nevertheless, it has been recently suggested that HAcAms can be formed independently, especially during chloramination of humic substances. When used as a disinfectant, monochloramine can also be a source of nitrogen for N-DBPs. This study investigated the role of aromatic organic matter in the formation of N-DBPs (HAcAms and HANs) upon chloramination. Formation kinetics were performed from various fractions of organic matter isolated from surface waters or treated wastewater effluents. Experiments were conducted with 15N-labeled monochloramine (15NH2Cl) to trace the origin of nitrogen. N-DBP formation showed a two-step profile: (1) a rapid formation following second-order reaction kinetics and incorporating nitrogen atom originating from the organic matrix (e.g., amine groups); and (2) a slower and linear increase correlated with exposure to chloramines, incorporating inorganic nitrogen (15N) from 15NH2Cl into aromatic moieties. Organic matter isolates showing high aromatic character (i.e., high SUVA) exhibited high reactivity characterized by a major incorporation of 15N in N-DBPs. A significantly lower incorporation was observed for low-aromatic-content organic matter. 15N-DCAcAm and 15N-DCAN formations exhibited a linear correlation, suggesting a similar behavior of 15N incorporation as SUVA increases. Chloramination of aromatic model compounds (i

  7. Succession of Biofilm Microbial Community during Nitrification in Lab-Scale Reactors Simulating Chloraminated Drinking Water Distribution System Conditions: the Impact of Simultaneously Increasing Monochloramine and Chlorine to Nitrogen Mass Ratios

    Science.gov (United States)

    Chloramination has been shown to promote nitrifying bacteria and 30 to 63% of utility plants using secondary chloramine disinfection experience nitrification episodes. Although nitrifying bacteria are not considered human pathogens, nitrification can affect drinking water qualit...

  8. Real-time ArcGIS and heterotrophic plate count based chloramine disinfectant control in water distribution system.

    Science.gov (United States)

    Bai, Xiaohui; Zhi, Xinghua; Zhu, Huifeng; Meng, Mingqun; Zhang, Mingde

    2015-01-01

    This study investigates the effect of chloramine residual on bacteria growth and regrowth and the relationship between heterotrophic plate counts (HPCs) and the concentration of chloramine residual in the Shanghai drinking water distribution system (DWDS). In this study, models to control HPCs in the water distribution system and consumer taps are also developed. Real-time ArcGIS was applied to show the distribution and changed results of the chloramine residual concentration in the pipe system by using these models. Residual regression analysis was used to get a reasonable range of the threshold values that allows the chloramine residual to efficiently inhibit bacteria growth in the Shanghai DWDS; the threshold values should be between 0.45 and 0.5 mg/L in pipe water and 0.2 and 0.25 mg/L in tap water. The low residual chloramine value (0.05 mg/L) of the Chinese drinking water quality standard may pose a potential health risk for microorganisms that should be improved. Disinfection by-products (DBPs) were detected, but no health risk was identified.

  9. Determinants of disinfectant pretreatment efficacy for nitrosamine control in chloraminated drinking water.

    Science.gov (United States)

    McCurry, Daniel L; Krasner, Stuart W; von Gunten, Urs; Mitch, William A

    2015-11-01

    Utilities using chloramines need strategies to mitigate nitrosamine formation to meet potential future nitrosamine regulations. The ability to reduce NDMA formation under typical post-chloramination conditions of pretreatment with ultraviolet light from a low pressure mercury lamp (LPUV), free chlorine (HOCl), ozone (O3), and UV light from a medium pressure mercury lamp (MPUV) were compared at exposures relevant to drinking water treatment. The order of efficacy after application to waters impacted by upstream wastewater discharges was O3 > HOCl ≈ MPUV > LPUV. NDMA precursor abatement generally did not correlate well between oxidants, and waters exhibited different behaviors with respect to pH and temperature, suggesting a variety of source-dependent NDMA precursors. For wastewater-impacted waters, the observed pH dependence for precursor abatement suggested the important role of secondary or tertiary amine precursors. Although hydroxyl radicals did not appear to be important for NDMA precursor abatement during O3 or MPUV pretreatment, the efficacy of MPUV correlated strongly with dissolved organic carbon concentration (p = 0.01), suggesting alternative indirect photochemical pathways. The temperature dependences during pre- and post-disinfection indicated that NDMA formation is likely to increase during warm seasons for O3 pretreatment, decrease for HOCl pretreatment, and remain unchanged for MPUV treatment, although seasonal changes in source water quality may counteract the temperature effects. For two waters impacted by relatively high polyDADMAC coagulant doses, pretreatment with HOCl, O3, and MPUV increased NDMA formation during post-chloramination. For O3 pretreatment, hydroxyl radicals likely led to precursor formation from the polymer in the latter tests. MPUV treatment of polymer-impacted water increased subsequent NDMA formation through an indirect photochemical process. Many factors may mitigate the importance of this increased NDMA formation

  10. Photolysis of inorganic chloramines and efficiency of trichloramine abatement by UV treatment of swimming pool water.

    Science.gov (United States)

    Soltermann, Fabian; Widler, Tobias; Canonica, Silvio; von Gunten, Urs

    2014-06-01

    Trichloramine, one of the three inorganic chloramines (mono-, di- and trichloramine), is a problematic disinfection by-product in recreational pool water since it causes skin and eye irritations as well as irritations of the respiratory tract. The most commonly used chloramine mitigation strategy in pool water is UV treatment. Experiments with membrane inlet mass spectrometry (MIMS) confirmed that inorganic chloramines are effectively degraded by UV irradiation with low-pressure (LP) and medium-pressure (MP) mercury lamps (apparent quantum yields (QY): NH2Cl = 0.50 (LP) and 0.31 (MP) mol einstein(-1), NHCl2: 1.06 (LP) and 0.85 (MP) mol einstein(-1)). Trichloramine showed the fastest depletion with a quantum yield slightly above 2 mol einstein(-1) in purified (LP and MP) and pool water (MP). This high quantum yield can partly be explained by reactions involving OH radicals (purified water) and the reaction of trichloramine with moieties formed during UV irradiation of pool water. The presence of free chlorine affects trichloramine degradation (QY: ∼1.5 mol einstein(-1)) since it scavenges OH radicals and competes with trichloramine for reactive species (e.g. organic amines). Measurements in a pool facility revealed that the installed UV reactors degraded trichloramine by 40-50% as expected from laboratory experiments. However, trichloramine reduction in the pools was less pronounced than in the UV reactors. Model calculations combining pool hydraulics with formation/abatement of trichloramine showed that there was a fast trichloramine formation in the pool from the residual chlorine and nitrogenous precursors. The main factors influencing trichloramine concentrations in pool water are the free chlorine concentration and the UV treatment in combination with the recirculation rate through the water treatment system.

  11. Effect of chloramine-T labeling conditions on the stability of monoclonal antibodies and their fragments

    International Nuclear Information System (INIS)

    Rapid in vivo degradation of radioiodinated monoclonal antibodies (MAb) has been reported. Conditions for radioiodination have varied. The purposes of this study were to compare the stability of MAb and their fragments when iodinated with chloramine-T (CT) under different conditions, and to compare methods for quality assessment of the radioiodinated molecules. A B-cell lymphoma MAb (Lym-1, IgG2a) and its FAb fragment, and a mammary cancer MAb(B6.01, IgG1) and its F(Ab')/sub 2/ fragment were iodinated with I-125 at CT:AB and I:Ab ratios of 1:1 and 1:10. Molecular sieving (TSK-3000) high performance liquid chromatography (HPLC), cellulose acetate electrophoresis (CAE) at 11 and 45 minutes and solid phase immunoreactivity (IRA) were used to observe stability of the molecules when stored at 40C. Radiochemical yield was greater than 95% in all instances. Iodination at CT:Ab and I:Ab ratios of 1:1 induced progressive degradation in all species which was most marked for the fragments. Iodination at CT:Ab and I:Ab ratios of 1:10 resulted in no observable degradation over 21 days. There was no significant difference in degradation between the IgG2a and IgG1 antibody when iodinated under identical circumstances. HPLC, CAE for 11 minutes and IRA, but not CAE for 45 minutes, revealed comparable changes. The authors conclude that lesser amounts of chloramine-T can be used to iodinate MAb and their fragments without loss of radiochemical efficiency and with improved stability of the species. MAb fragments are more vulnerable to chloramine-T. These observations may explain, at least in part, rapid in vivo degradation of radioiodinated MAb

  12. Comparison of chlorine and chloramine in the release of mercury from dental amalgam.

    Science.gov (United States)

    Stone, Mark E; Scott, John W; Schultz, Stephen T; Berry, Denise L; Wilcoxon, Monte; Piwoni, Marv; Panno, Brent; Bordson, Gary

    2009-01-01

    The purpose of this project was to compare the ability of chlorine (HOCl/OCl(-)) and monochloramine (NH(2)Cl) to mobilize mercury from dental amalgam. Two types of amalgam were used in this investigation: laboratory-prepared amalgam and samples obtained from dental-unit wastewater. For disinfectant exposure simulations, 0.5 g of either the laboratory-generated or clinically obtained amalgam waste was added to 250 mL amber bottles. The amalgam samples were agitated by end-over-end rotation at 30 rpm in the presence of 1 mg/L chlorine, 10 mg/L chlorine, 1 mg/L monochloramine, 10 mg/L monochloramine, or deionized water for intervals of 0 h, 2 h, 4 h, 8 h, and 24 h for the clinically obtained amalgam waste samples and 4 h and 24 h for the laboratory-prepared samples. Chlorine and monochloramine concentrations were measured with a spectrophotometer. Samples were filtered through a 0.45 microm membrane filter and analyzed for mercury with USEPA standard method 245.7. When the two sample types were combined, the mean mercury level in the 1 mg/L chlorine group was 0.020 mg/L (n=25, SD=0.008). The 10 mg/L chlorine group had a mean mercury concentration of 0.59 mg/L (n=25, SD=1.06). The 1 mg/L chloramine group had a mean mercury level of 0.023 mg/L (n=25, SD=0.010). The 10 mg/L chloramine group had a mean mercury level of 0.024 mg/L (n=25, SD=0.011). Independent samples t-tests showed that there was a significant difference between the natural log mercury measurements of 10 mg/L chlorine compared to those of 1 mg/L and 10 mg/L chloramine. Changing from chlorine to chloramine disinfection at water treatment plants would not be expected to produce substantial increases in dissolved mercury levels in dental-unit wastewater.

  13. Iodine-Catalyzed Decarboxylative Amidation of β,γ-Unsaturated Carboxylic Acids with Chloramine Salts Leading to Allylic Amides.

    Science.gov (United States)

    Kiyokawa, Kensuke; Kojima, Takumi; Hishikawa, Yusuke; Minakata, Satoshi

    2015-10-26

    The iodine-catalyzed decarboxylative amidation of β,γ-unsaturated carboxylic acids with chloramine salts is described. This method enables the regioselective synthesis of allylic amides from various types of β,γ-unsaturated carboxylic acids containing substituents at the α- and β-positions. In the reaction, N-iodo-N-chloroamides, generated by the reaction of a chloramine salt with I2 , function as a key active species. The reaction provides an attractive alternative to existing methods for the synthesis of useful secondary allylic amine derivatives. PMID:26493878

  14. Using micro-quantity of chloramine T in chicken pro-latin labelling and radioimmunoassay

    International Nuclear Information System (INIS)

    A radioimmunoassay was developed for measurement of chicken plasma prolactin. The assay used chPRL(AFP-10328B) as reference standard, chPRL(AFP-4444B) as the radio labelled ligand, rabbit anti-chicken PRL (AFP-151040789) as first antibody, and donkey anti-rabbit IgG antiserum as second antibody. For iodide ratio labelling of chicken PRL, a modified chloramine T method which reduced the amount of chloramine T and omitted sodium metabisulfite, and produced the labelled hormone with a specific activity of 29μCi/μg was used. The assay sensitivity was 0.34 ng/ml. the ED75, ED50 and ED25 of standard curve were 1.30, 3.71 and 10.60 ng/ml, respectively. Both coefficients of variations between and within assay were less than 15%. Serial dilutions of chicken samples showed a parallel inhibition curve to that of the standards. Plasma PRL concentrations of samples from hens at different reproductive states measured by this assay revealed significant differences and rational changing trends. These results validate the assay

  15. Correlation between SUVA and DBP formation during chlorination and chloramination of NOM fractions from different sources.

    Science.gov (United States)

    Hua, Guanghui; Reckhow, David A; Abusallout, Ibrahim

    2015-07-01

    Natural organic matter (NOM) is the major precursor to the formation of disinfection byproducts (DBPs) during drinking water treatment. Specific ultraviolet absorbance (SUVA) is a widely used surrogate parameter to characterize NOM and predict its DBP formation potential. The objective of this study was to determine the relationships between SUVA and different classes of DBPs formed by NOM fractions from different sources. Three natural waters with a wide SUVA range were fractionated into differing hydrophobicity and molecular weight groups using XAD-4 and XAD-8 resins and ultrafiltration membranes. Each NOM fraction was treated with chlorine and monochloramine under controlled laboratory conditions. Different classes of DBPs showed different relationships with SUVA. SUVA correlated strongly with trihaloacetic acids (THAAs) and unknown total organic halogen (UTOX) yields whereas weak correlations were observed between SUVA and trihalomethane (THM) and dihaloacetic acid (DHAA) yields during chlorination. These results reinforce the hypothesis that DHAAs and THAAs form through different precursors and reaction pathways. Strong correlation between SUVA and UTOX was also observed during chloramination. However, no significant relationship was observed between SUVA and chloramination THMs and DHAAs. Overall, SUVA is a good indicator for the formation of unknown DBPs. This indicates that UV absorbing compounds and aromatic carbon within NOM are the primary sources of precursors for unknown DBPs.

  16. OCCURRENCE OF IODO-ACID AND IODO-THM DISINFECTION BY-PRODUCTS IN CHLORAMINATED DRINKING WATER

    Science.gov (United States)

    Iodo-acids were recently identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid (IAA), bromoiodoacetic acid, (E)-3-bromo-3-iodo-propenoic acid, (Z)-3-bromo-3-iodo-propenoic acid, and (E)-2-iodo-3...

  17. Comparison of Microbial Communities in a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification (poster)

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system (i.e. PVC pipe loop). After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The s...

  18. Inhalation exposure to chloramine T induces DNA damage and inflammation in lung of Sprague-Dawley rats.

    Science.gov (United States)

    Shim, Ilseob; Seo, Gyun-Baek; Oh, Eunha; Lee, Mimi; Kwon, Jung-Taek; Sul, Donggeun; Lee, Byung-Woo; Yoon, Byung-Il; Kim, Pilje; Choi, Kyunghee; Kim, Hyun-Mi

    2013-01-01

    Chloramine T has been widely used as a disinfectant in many areas such as kitchens, laboratories and hospitals. It has been also used as a biocide in air fresheners and deodorants which are consumer products; however, little is known about its toxic effects by inhalation route. This study was performed to identify the subacute inhalation toxicity of chloramine T under whole-body inhalation exposure conditions. Male and female groups of rats were exposed to chloramine T at concentrations of 0.2, 0.9 and 4.0 mg/m³ for 6 hr/day, 5 days/week during 4 weeks. After 28-day repeated inhalation of chloramine T, there were dose-dependently significant DNA damage in the rat tissues evaluated and inflammation was histopathologically noted around the terminal airways of the lung in both genders. As a result of the expression of three types of antioxidant enzymes (SOD-2, GPx-1, PRX-1) in rat's lung after exposure, there was no significant change of all antioxidant enzymes in the male and female rats. The results showed that no observed adverse effect level (NOAEL) was 0.2 mg/m³ in male rats and 0.9 mg/m³ in female rats under the present experimental condition.

  19. A Long-Term Study of the Microbial Community Structure in a Simulated Chloraminated Drinking Water Distribution System

    Science.gov (United States)

    Free chlorine is used as the primary disinfectant in most drinking water distribution systems(DWDS). However, chlorine disinfection promotes the formation of disinfectant by-products (DBPs)and as a result, many US water treatment facilities use chloramination to ensure regulatory...

  20. Comparison of chlorination and chloramination in carbonaceous and nitrogenous disinfection byproduct formation potentials with prolonged contact time.

    Science.gov (United States)

    Sakai, Hiroshi; Tokuhara, Shunsuke; Murakami, Michio; Kosaka, Koji; Oguma, Kumiko; Takizawa, Satoshi

    2016-01-01

    Due to decreasing water demands in Japan, hydraulic retention times of water in piped supply systems has been extended, resulting in a longer contact time with disinfectants. However, the effects of extended contact time on the formation of various disinfection byproducts (DBPs), including carbonaceous DBPs such as trihalomethane (THM) and haloacetic acid (HAA), and nitrogenous DBPs such as nitrosodimethylamine (NDMA) and nitrosomorpholine (NMor), have not yet been investigated in detail. Herein, we compared the formation of these DBPs by chlorination and chloramination for five water samples collected from rivers and a dam in Japan, all of which represent municipal water supply sources. Water samples were treated by either filtration or a combination of coagulation and filtration. Treated samples were subjected to a DBP formation potential test by either chlorine or chloramine for contact times of 1 day or 4 days. Four THM species, nine HAA species, NDMA, and NMor were measured by GC-ECD or UPLC-MS/MS. Lifetime cancer risk was calculated based on the Integrated Risk Information System unit risk information. The experiment and analysis focused on (i) prolonged contact time from 1 day to 4 days, (ii) reduction efficiency by conventional treatment, (iii) correlations between DBP formation potentials and water quality parameters, and (iv) the contribution of each species to total risk. With an increased contact time from 1 day to 4 days, THM formation increased to 420% by chloramination. Coagulation-filtration treatment showed that brominated species in THMs are less likely to be reduced. With the highest unit risk among THM species, dibromochloromethane (DBCM) showed a high correlation with bromine, but not with organic matter parameters. NDMA contributed to lifetime cancer risk. The THM formation pathway should be revisited in terms of chloramination and bromine incorporation. It is also recommended to investigate nitrosamine formation potential by

  1. Comparative Genomic Analysis of Nontuberculous Mycobacteria (NTM) and Environmental Isolates Associated with a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification - poster #2168

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system. After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The distribution system wa...

  2. Comparative Genomic Analysis of Nontuberculous Mycobacteria (NTM) and Environmental isolates associated with a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system. After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The distribution system ...

  3. Draft genome sequence of two Shingopyxis sp. strains H107 and H115 isolated from a chloraminated drinking water distriburion system simulator

    Data.gov (United States)

    U.S. Environmental Protection Agency — Draft genome sequence of two Shingopyxis sp. strains H107 and H115 isolated from a chloraminated drinking water distriburion system simulator This dataset is...

  4. Identification of tobacco-specific nitrosamines as disinfection byproducts in chloraminated water.

    Science.gov (United States)

    Wu, Minghuo; Qian, Yichao; Boyd, Jessica M; Leavey, Shannon; Hrudey, Steve E; Krasner, Stuart W; Li, Xing-Fang

    2014-01-01

    Tobacco-specific nitrosamines (TSNAs) exist in environmental waters; however, it is unknown whether TSNAs can be produced during water disinfection. Here we report on the investigation and evidence of TSNAs as a new class of disinfection byproducts (DBPs). Using five common TSNAs, including (methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) as the targets, we first developed a solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method capable of rapidly determining these TSNAs at levels as low as 0.02 ng/L in treated water. Using this highly sensitive method, we investigated the occurrence and formation potential (FP) (precursor test conducted in the presence of chloramines) of TSNAs in treated water from two wastewater treatment plants (WWTPs) and seven drinking water treatment plants (DWTPs). NNAL was detected in the FP samples, but not in the samples before the FP test, confirming NNAL as a DBP. NNK was detected in the treated wastewater before the FP test, but its concentration increased significantly after chloramination in two of three tests. Thus, NNK could be a DBP and/or a contaminant in wastewater. Moreover, these TSNAs were detected in FP tests of wastewater-impacted DWTP plant influents in 9 of 11 samples. However, TSNAs were not detected at full-scale DWTPs, except for at one DWTP with high ammonia where breakpoint chlorination was not achieved. The concentration of the sum of five TSNAs (0.3 ng/L) was 100-fold lower than NDMA, suggesting that TSNAs have a minor contribution to total nitrosamines in water. We examined several factors in the treatment process and found that chlorine or ozone may destroy TSNA precursors and granular activated carbon (GAC) treatment may remove the precursors. Further research is warranted into the efficiency of these processes at different DWTPs using sources of varying water quality.

  5. Occurrences of nitrosamines in chlorinated and chloraminated drinking water in three representative cities, China.

    Science.gov (United States)

    Luo, Qian; Wang, Donghong; Wang, Zijian

    2012-10-15

    An investigation of the occurrence of nine nitrosamines in drinking water following different water treatment processes was conducted using samples from seven drinking water treatment plants in three cities and tap waters in one city in China. The total nitrosamine levels ranged from not detected (n.d.) to 43.45 ng/L. The species and concentrations of the nine nitrosamines varied with disinfection methods and source waters. N-nitrosodimethylamine (NDMA), which is the nitrosamines of greatest concern, was identified in raw water, disinfecting water, finished water and tap water samples, ranging from 0.8 to 21.6, 0.12 to 24.2, n.d. to 8.8, and n.d. to 13.3 ng/L, respectively. Chloramination alone produced the most significant amounts of NDMA, while ozonation followed by chloramination led to moderately reduced levels. Additionally, chlorination produced relatively less NDMA, while low pressure ultraviolet radiation followed by chlorination could also significantly reduce them. Total organic carbon is one of the most important factors influencing nitrosamines formation in disinfecting water. In contrast, the addition of chlorine following any other disinfection was found to increase the formation of the other eight species of nitrosamines. The three nitrosamines recommended for monitoring by the US EPA were detected in the tap water samples, but most were present at levels below those that pose a risk to human health. Nevertheless, the occurrence and concentration of nitrosamines regulated in the Drinking Water Contaminant Candidate List could cause some potential human effects and therefore warrant attention.

  6. Effects of ozone and ozone/peroxide pretreatments on disinfection byproduct formation during subsequent chlorination and chloramination.

    Science.gov (United States)

    Yang, Xin; Peng, Jinfeng; Chen, Baiyang; Guo, Wanhong; Liang, Yongmei; Liu, Wei; Liu, Lu

    2012-11-15

    Ozone (O3) and ozone/hydrogen peroxide (O3/H2O2) can be used in water treatment facilities to remove many organic micropollutants with taste, odor, and color implications. The effects of O3 and O3/H2O2 on the formation of disinfection byproducts (DBPs) in subsequent chlorination and chloramination processes, however, are not well determined. In this study, we compared the yields of a series of regulated and emerging DBPs during sequenced O3-Cl2, O3/H2O2-Cl2, O3-NH2Cl, and O3/H2O2-NH2Cl oxidation of 11 samples, each with different hydrophobicity, bromide concentration, soluble microbial products, and humic substances. For most water, pretreatment with O3 and O3/H2O2 increased the formation of chloral hydrate (CH), trichloronitromethane (TCNM) and haloketones (HKs) but lowered the yields of haloacetonitriles (HANs) during chlorination processes. Compared with O3 alone, O3/H2O2 in combination generated more CH and HKs during chlorination, and their extents of formation appeared to depend on the O3 doses. In terms of chloramination, both O3 and O3/H2O2 reduced THM, HAA, and HAN formation significantly without increasing CH, TCNM, or HKs. These results suggest that O3 or O3/H2O2 pretreatments may provide some benefits for the chloramination process in controlling regulated and emerging DBPs in waters without high bromide content. PMID:23009791

  7. Modelling combined effect of chloramine and copper on ammonia-oxidizing microbial activity using a biostability approach.

    Science.gov (United States)

    Sarker, Dipok Chandra; Sathasivan, Arumugam; Rittmann, Bruce E

    2015-11-01

    Continuous and batch laboratory experiments were used to evaluate the combined effects of copper and chloramine on ammonia oxidizing microbes present in otherwise high nitrifying water samples. The experimental data were analyzed using a biostability concept and quantified with the biostable residual concentratrion (BRC) of monochloramine, or the concentration that prevents the onset of nitrification. In the batch experiments, copper dosing ≥0.25 mg-Cu L(-1) resulted in complete inhibition of nitrification, and a lower copper dosing (0.1 mg-Cu L(-1)) delayed nitrification. The BRC was systematically lowered with the addition of copper. For example, a free-ammonium concentration of 0.1 mg-N L(-1) had a BRC of 0.73 mg-Cl2 L(-1) with no Cu, but addition of 0.1 mg-Cu L(-1) lowered the BRC to 0.16 mg-Cl2 L(-1), while addition of 0.25 mg-Cu L(-1) eliminated the need to add chloramine (BRC = 0). A non-competitive inhibition model fit the experimental data well with a copper threshold of 0.044 mg-Cu L(-1) and can be used to estimate Cu doses needed to prevent nitrification based on the chloramine concentration. Full scale systems applications need further study.

  8. Occurrences of nitrosamines in chlorinated and chloraminated drinking water in three representative cities, China

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Qian; Wang, Donghong; Wang, Zijian, E-mail: wangzj@rcees.ac.cn

    2012-10-15

    An investigation of the occurrence of nine nitrosamines in drinking water following different water treatment processes was conducted using samples from seven drinking water treatment plants in three cities and tap waters in one city in China. The total nitrosamine levels ranged from not detected (n.d.) to 43.45 ng/L. The species and concentrations of the nine nitrosamines varied with disinfection methods and source waters. N-nitrosodimethylamine (NDMA), which is the nitrosamines of greatest concern, was identified in raw water, disinfecting water, finished water and tap water samples, ranging from 0.8 to 21.6, 0.12 to 24.2, n.d. to 8.8, and n.d. to 13.3 ng/L, respectively. Chloramination alone produced the most significant amounts of NDMA, while ozonation followed by chloramination led to moderately reduced levels. Additionally, chlorination produced relatively less NDMA, while low pressure ultraviolet radiation followed by chlorination could also significantly reduce them. Total organic carbon is one of the most important factors influencing nitrosamines formation in disinfecting water. In contrast, the addition of chlorine following any other disinfection was found to increase the formation of the other eight species of nitrosamines. The three nitrosamines recommended for monitoring by the US EPA were detected in the tap water samples, but most were present at levels below those that pose a risk to human health. Nevertheless, the occurrence and concentration of nitrosamines regulated in the Drinking Water Contaminant Candidate List could cause some potential human effects and therefore warrant attention. Highlights: Black-Right-Pointing-Pointer Nitrosamines in disinfected drinking water in three Chinese cities were investigated. Black-Right-Pointing-Pointer Some nitrosamines could be detected in raw water. Black-Right-Pointing-Pointer Advanced treatment affects nitrosamine levels both positively and negatively. Black-Right-Pointing-Pointer Organic matters

  9. The effect of inorganic precursors on disinfection byproduct formation during UV-chlorine/chloramine drinking water treatment.

    Science.gov (United States)

    Lyon, Bonnie A; Dotson, Aaron D; Linden, Karl G; Weinberg, Howard S

    2012-10-01

    Ultraviolet (UV) disinfection is being increasingly used in drinking water treatment. It is important to understand how its application to different types of water may influence finished water quality, particularly as anthropogenic activity continues to impact the quality of source waters. The objective of this study was to evaluate the effect of inorganic precursors on the formation of regulated and unregulated disinfection byproducts (DBPs) during UV irradiation of surface waters when combined with chlorination or chloramination. Samples were collected from three drinking water utilities supplied by source waters with varying organic and inorganic precursor content. The filtered samples were treated in the laboratory with a range of UV doses delivered from low pressure (LP, UV output at 253.7 nm) and medium pressure (MP, polychromatic UV output 200-400 nm) mercury lamps followed by chlorination or chloramination, in the presence and absence of additional bromide and nitrate. The regulated trihalomethanes and haloacetic acids were not affected by UV pretreatment at disinfection doses (40-186 mJ/cm²). With higher doses (1000 mJ/cm²), trihalomethane formation was increased 30-40%. While most effects on DBPs were only observed with doses much higher than typically used for UV disinfection, there were some effects on unregulated DBPs at lower doses. In nitrate-spiked samples (1-10 mg N/L), chloropicrin formation doubled and increased three- to six-fold with 40 mJ/cm² MP UV followed by chloramination and chlorination, respectively. Bromopicrin formation was increased in samples containing bromide (0.5-1 mg/L) and nitrate (1-10 mg N/L) when pretreated with LP or MP UV (30-60% with 40 mJ/cm² LP UV and four- to ten-fold increase with 40 mJ/cm² MP UV, after subsequent chlorination). The formation of cyanogen chloride doubled and increased three-fold with MP UV doses of 186 and 1000 mJ/cm², respectively, when followed by chloramination in nitrate-spiked samples but

  10. Influence Factors of Chloramine Decay in Bulk Water%氯胺在管网中水相衰减影响因素研究

    Institute of Scientific and Technical Information of China (English)

    张永吉; 曾果; 周玲玲; 宋正国; 邓慧萍

    2012-01-01

    Water quality parameters including chlorine to ammonia nitrogen application ratio w(Cl)∶w(N),initial chloramine concentration,organic compound level,nitrite concentration,temperature and pH,which affect chloramines decay,are investigated in pure water and the water of a distribution system.Results show that chloramine can autodecompose in pure water.w(Cl)∶w(N) and initial chloramine concentration influence its decay rate.The rate of chloramine decay is higher in bulk water of the distribution system than that in pure water.Chloramine is more stable with w Cl∶w(N)=4∶1 than that of w(Cl)∶w(N)=3∶1.Initial chloramine concentration is an important factor inducing the high rate of chloramines decay with high initial chloramine concentration.The rate of Chloramines decay increases with increasing organic compound and nitrite concentration.The temperature inpacts on the rate of chloramines decay,which means high decay rate in bulk water with increasing temperature.In addition,the reaction of chloramines decay is a type of acid-catalysis,and lower pH elevates the rate of chloramines decay.%以纯水和管网水为研究对象,分别考察了氯氨比、氯胺质量浓度、总有机碳(total organic carbon,TOC)浓度、NO2--N质量浓度、温度θ和pH等水质参数对氯胺衰减的影响.研究结果表明,氯胺在纯水中存在自衰减现象,氯氨比和初始氯胺质量浓度对其自衰减都有一定影响.管网水中氯胺的衰减速率则明显大于同条件下纯水中氯胺的衰减速率,w(Cl)∶w(N)=4∶1的氯氨比w(Cl)∶w(N)=3∶1的氯胺具有更好的稳定性.氯胺初始质量浓度是氯胺衰减的重要因素,初始质量浓度越大,氯胺衰减的速率越快;水中有机物和NO2--N质量浓度的增加会提高氯胺衰减速率;温度对氯胺的衰减有明显影响,随温度升高,氯胺在水相中消耗变快;氯胺的衰减属于酸催化反应,pH的降低会增加氯胺的衰减速率.

  11. Formation of nitrogenous disinfection by-products in 10 chlorinated and chloraminated drinking water supply systems.

    Science.gov (United States)

    Liew, Deborah; Linge, Kathryn L; Joll, Cynthia A

    2016-09-01

    The presence of nitrogenous disinfection by-products (N-DBPs) in drinking water supplies is a public health concern, particularly since some N-DBPs have been reported to be more toxic than the regulated trihalomethanes and haloacetic acids. In this paper, a comprehensive evaluation of the presence of N-DBPs in 10 drinking water supply systems in Western Australia is presented. A suite of 28 N-DBPs, including N-nitrosamines, haloacetonitriles (HANs), haloacetamides (HAAms) and halonitromethanes (HNMs), were measured and evaluated for relationships with bulk parameters in the waters before disinfection. A number of N-DBPs were frequently detected in disinfected waters, although at generally low concentrations (water, N-DBP concentrations were significantly correlated with dissolved organic carbon (DOC) and ammonia, and these, in addition to high bromide in one of the waters, led to elevated concentrations of brominated HANs (26.6 μg/L of dibromoacetonitrile). There were significant differences in the occurrence of all classes of N-DBPs between chlorinated and chloraminated waters, except for HNMs, which were detected at relatively low concentrations in both water types. Trends observed in one large distribution system suggest that N-DBPs can continue to form or degrade within distribution systems, and redosing of disinfectant may cause further by-product formation.

  12. Spectrophotometric determination of bio-active compounds with chloramine-T and gallocyanine.

    Science.gov (United States)

    Sastry, C S; Srinivas, K R; Prasad, K M

    1996-10-01

    A simple, sensitive and selective method for the spectrophotometric determination of drugs, viz., sulphamethoxazole, tetracycline HCl, amidopyrine, nifurtimox and isoniazid and biologically important amino acids, cysteine, aspartic acid and arginine based on their reactivity with chloramine-T (CAT) is proposed. The method involves the addition of excess CAT of a known concentration in the presence of 0.25 M HCl and the determination of the unreacted CAT by measurement of the decrease in the absorbance of the dye, gallocyanine (lambda(max): 540 nm), the most suitable of several dyes that were tested. This method was applied to the determination of drug contents in pharmaceutical formulations and to the measurement of the aspartic acid content of some protein hydrolysates. The method is useful for the determination of the target compounds in microgram quantities from 0.4-5.6 microg mL(-1) with the exceptions of arginine (1.0-8.0 microg mL(-1)) and nifurtimox (0.8-5.6 microg mL(-1)). Standard deviations were typically 0.5 mg per dose (RSD 0.5-1.2%). No interferences were observed from common excipients in formulations, and detailed interference studies of other amino acids in the determination of cysteine, aspartic acid and arginine are reported. The validity of the method was tested against spectrophotometric and titrimetric reference methods. Recoveries were 99.8-102.1%. PMID:18966644

  13. Oxidation of Tetracaine Hydrochloride by Chloramine-B in Acid Medium: Kinetic Modeling

    Directory of Open Access Journals (Sweden)

    Jayachamarajapura Pranesh Shubha

    2014-01-01

    Full Text Available Tetracaine hydrochloride (TCH is one of the potent local anaesthetics. A kinetic study of oxidation of tetracaine hydrochloride by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB has been carried in HClO4 medium at 303 K. The rate shows first-order dependence on [CAB]o, shows fractional–order dependence on [substrate]o, and is self-governing on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increased the rate. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction was found to be 1 : 5 and the oxidation products were identified by spectral analysis. The conjugate free acid C6H5SO2NHCl of CAB is postulated as the reactive oxidizing species. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

  14. Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

    Science.gov (United States)

    Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

    2014-10-21

    Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

  15. Formation of disinfection byproducts upon chlorine dioxide preoxidation followed by chlorination or chloramination of natural organic matter.

    Science.gov (United States)

    Yang, Xin; Guo, Wanhong; Lee, Wontae

    2013-06-01

    Chlorine dioxide (ClO2) is often used as an oxidant to remove taste, odor and color during water treatment. Due to the concerns of the chlorite formation, chlorination or chloramination is often applied after ClO2 preoxidation. We investigated the formation of regulated and emerging disinfection byproducts (DBPs) in sequential ClO2-chlorination and ClO2-chloramination processes. To clarify the relationship between the formation of DBPs and the characteristics of natural organic matter (NOM), changes in the properties of NOM before and after ClO2 oxidation were characterized by fluorescence, Fourier transform infrared spectroscopy (FTIR), and size and resin fractionation techniques. ClO2 preoxidation destroyed the aromatic and conjugated structures of NOM and transformed large aromatic and long aliphatic chain organics to small and hydrophilic organics. Treatment with ClO2 alone did not produce significant amount of trihalomethanes (THMs) and haloacetic acids (HAAs), but produced chlorite. ClO2 preoxidation reduced THMs, HAAs, haloacetonitriles (HANs) and chloral hydrate (CH) during subsequent chlorination, but no reduction of THMs was observed during chloramination. Increasing ClO2 doses enhanced the reduction of most DBPs except halonitromethanes (HNMs) and haloketones (HKs). The presence of bromide increased the formation of total amount of DBPs and also shifted DBPs to more brominated ones. Bromine incorporation was higher in ClO2 treated samples. The results indicated that ClO2 preoxidation prior to chlorination is applicable for control of THM, HAA and HAN in both pristine and polluted waters, but chlorite formation is a concern and HNMs and HKs are not effectively controlled by ClO2 preoxidation.

  16. Changes in dissolved organic matter fluorescence and disinfection byproduct formation from UV and subsequent chlorination/chloramination

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, Bonnie A.; Cory, Rose M.; Weinberg, Howard S., E-mail: howard_weinberg@unc.edu

    2014-01-15

    Highlights: • DBP formation from UV-chlorine/chloramine drinking water treatment was measured. • The effect of UV on DBP precursors was evaluated by fluorescence and PARAFAC. • UV alone decreased protein/tryptophan- and humic-like fluorescence. • Loss of two components correlated with cyanogen chloride formation (R{sup 2} = 0.79–0.91). • Loss of the components also correlated with chloral hydrate formation (R{sup 2} = 0.95–1.000). -- Abstract: Ultraviolet (UV) irradiation is being increasingly used to help drinking water utilities meet finished water quality regulations, but its influence on disinfection byproduct (DBP) precursors and DBP formation is not completely understood. This study investigated the effect of medium pressure (MP) UV combined with chlorination/chloramination on the fluorescent fraction of dissolved organic matter (DOM) isolated from a United States surface water with median total organic carbon content. Parallel factor analysis was used to understand how UV may alter the capacity of DOM to form DBPs of potential human health concern. The production of chloral hydrate and cyanogen chloride from MP UV followed by chlorine or chloramine, respectively, correlated with a decrease in fluorescence intensity of a protein/tryptophan-like component (R{sup 2} = 0.79–0.99) and a humic-like component (R{sup 2} = 0.91–1.00). This suggests that the UV-induced precursors to these compounds originated from DOM with similar characteristics to these components. The fluorescent DOM components identified in this study are similar to reoccurring components that have been previously identified in a range of raw and treated waters, and this work demonstrates the value of using fluorescence analysis of DOM to understand the relationships between DOM source and DBP formation under a range of treatment conditions.

  17. Taurine chloramine-induced inactivation of cofilin protein through methionine oxidation.

    Science.gov (United States)

    Luo, Shen; Uehara, Hiroshi; Shacter, Emily

    2014-10-01

    Cofilin regulates reorganization of actin filaments (F-actin) in eukaryotes. A recent finding has demonstrated that oxidation of cofilin by taurine chloramine (TnCl), a physiological oxidant derived from neutrophils, causes cofilin to translocate to the mitochondria inducing apoptosis (F. Klamt et al. Nat. Cell Biol.11:1241-1246; 2009). Here we investigated the effect of TnCl on biological activities of cofilin in vitro. Our data show that TnCl-induced oxidation of recombinant human cofilin-1 inhibits its F-actin-binding and depolymerization activities. Native cofilin contains four free Cys and three Met residues. Incubation of oxidized cofilin with DTT does not lead to its reactivation. A double Cys to Ala mutation on the two C-terminal Cys shows similar biological activities as the wild type, but does not prevent the TnCl-induced inactivation. In contrast, incubation of oxidized cofilin with methionine sulfoxide reductases results in its reactivation. Phosphorylation is known to inhibit cofilin activities. We found that Met oxidation also prevents phosphorylation of cofilin, which is reversed by incubating oxidized cofilin with methionine sulfoxide reductases. Interestingly, intact protein mass spectrometry of the oxidized mutant indicated one major oxidation product with an additional mass of 16 Da, consistent with oxidation of one specific Met residue. This residue was identified as Met-115 by peptide mapping and tandem mass spectrometry. It is adjacent to Lys-114, a known residue on globular-actin-binding site, implying that oxidation of Met-115 disrupts the globular-actin-binding site of cofilin, which causes TnCl-induced inactivation. The findings identify Met-115 as a redox switch on cofilin that regulates its biological activity.

  18. Formation of emerging DBPs from the chlorination and chloramination of seawater algal organic matter and related model compounds

    KAUST Repository

    Nihemaiti, Maolida

    2014-05-01

    Limited studies focused on reactions occurring during disinfection and oxidation processes of seawater. The aim of this work was to investigate disinfection by-products (DBPs) formation from the chlorination and chloramination of seawater algal organic matter and related model compounds. Simulated algal blooms directly growing in Red Sea, red tide samples collected during an algal bloom event and Hymenomonas sp. monoculture were studied as algal organic matter sources. Experiments were conducted in synthetic seawater containing bromide ion. A variety of DBPs was formed from the chlorination and chloramination of algal organic matter. Brominated DBPs (bromoform, DBAA, DBAN and DBAcAm) were the dominant species. Iodinated DBPs (CIAcAm and iodinated THMs) were detected, which are known to be highly toxic compared to their chlorinated or brominated analogues. Algal organic matter was found to incorporate important precursors of nitrogenous DBPs (N-DBPs), which have been reported to be more toxic than regulated THMs and HAAs. Isotopically-labeled monochloramine (15N- NH2Cl) was used in order to investigate the nitrogen source in N-DBPs. High formation of N-DBPs was found from Hymenomonas sp. sample in exponential growth phase, which was enriched in nitrogen-containing organic compounds. High inorganic nitrogen incorporation was found from the algal samples enriched in humic-like compounds. HAcAms formation was studied from chlorination and chloramination of amino acids. Asparagine, aspartic acid and other amino acids with an aromatic structure were found to be important precursors of HAcAms and DCAN. Factors affecting HAcAms formation (Cl2/ amino acid molar ratio and pH) were evaluated. Studies on the formation kinetics of DCAcAm and DCAN from asparagine suggested a rapid formation of DCAcAm from organic nitrogen (amide group) and a slower incorporation of inorganic nitrogen coming from monochloramine to form DCAN. High amounts of DCAN and DCAcAm were detected from the

  19. Characterization of iodinated disinfection by-products in chlorinated and chloraminated waters using Orbitrap based gas chromatography-mass spectrometry.

    Science.gov (United States)

    Postigo, Cristina; Cojocariu, Cristian I; Richardson, Susan D; Silcock, Paul J; Barcelo, Damia

    2016-05-01

    Recent developments in gas chromatography (GC)-mass spectrometry (MS) have opened up the possibility to use the high resolution-accurate mass (HRAM) Orbitrap mass analyzer to further characterize the volatile and semivolatile fractions of environmental samples. This work describes the utilization of GC Orbitrap MS technology to characterize iodine-containing disinfection by-products (iodo-DBPs) in chlorinated and chloraminated DBP mixture concentrates. These DBP mixtures were generated in lab-scale disinfection reactions using Llobregat river water and solutions containing Nordic Lake natural organic matter (NOM). The DBPs generated were concentrated using XAD resins, and extracts obtained were analyzed in full scan mode with the GC Orbitrap MS. Integration of high resolution accurate mass information and fragment rationalization allowed the characterization of up to 11 different iodo-DBPs in the water extracts analyzed, including one new iodo-DBP reported for the first time. Overall, formation of iodo-DBPs was enhanced during chloramination reactions. As expected, NOM characteristics and iodide and bromide content of the tested waters affected the amount and type of iodo-DBPs generated. Graphical Abstract Characterization of iodo-DBPs in DBP mixtures based on high resolution accurate mass data obtained by means of GC Orbitrap MS analysis. PMID:27007731

  20. Changes in dissolved organic matter fluorescence and disinfection byproduct formation from UV and subsequent chlorination/chloramination.

    Science.gov (United States)

    Lyon, Bonnie A; Cory, Rose M; Weinberg, Howard S

    2014-01-15

    Ultraviolet (UV) irradiation is being increasingly used to help drinking water utilities meet finished water quality regulations, but its influence on disinfection byproduct (DBP) precursors and DBP formation is not completely understood. This study investigated the effect of medium pressure (MP) UV combined with chlorination/chloramination on the fluorescent fraction of dissolved organic matter (DOM) isolated from a United States surface water with median total organic carbon content. Parallel factor analysis was used to understand how UV may alter the capacity of DOM to form DBPs of potential human health concern. The production of chloral hydrate and cyanogen chloride from MP UV followed by chlorine or chloramine, respectively, correlated with a decrease in fluorescence intensity of a protein/tryptophan-like component (R(2)=0.79-0.99) and a humic-like component (R(2)=0.91-1.00). This suggests that the UV-induced precursors to these compounds originated from DOM with similar characteristics to these components. The fluorescent DOM components identified in this study are similar to reoccurring components that have been previously identified in a range of raw and treated waters, and this work demonstrates the value of using fluorescence analysis of DOM to understand the relationships between DOM source and DBP formation under a range of treatment conditions.

  1. Immunotoxicological profile of chloramine in female B6C3F1 mice when administered in the drinking water for 28 days.

    Science.gov (United States)

    Guo, Tai L; Germolec, Dori R; Collins, Bradley J; Luebke, Robert W; Auttachoat, Wimolnut; Smith, Matthew J; White, Kimber L

    2011-01-01

    Monochloramine has been used to provide a disinfecting residual in water distribution systems where it is difficult to maintain an adequate free-chlorine residual or where disinfection by-product formation is of concern. The goal of this study was to characterize the immunotoxic effects of chloramine in female B(6)C(3)F(1) mice when administered via the drinking water. Mice were exposed to chloramine-containing deionized tap water at 2, 10, 20, 100, or 200 ppm for 28 days. No statistically significant differences in drinking water consumption, body weight, body weight gain, organ weights, or hematological parameters between the exposed and control animals were noted during the experimental period. There were no changes in the percentages and numbers of total B-lymphocytes, T-lymphocytes, CD4(+) and CD8(+) T-lymphocytes, natural killer (NK) cells, and macrophages in the spleen. Exposure to chloramine did not affect the IgM antibody-forming cell response to sheep red blood cells (SRBC) or anti-SRBC IgM antibody production. Minimal effects, judged to be biologically insignificant, were observed in the mixed-leukocyte response and NK activity. In conclusion, chloramine produced no toxicological and immunotoxic effects in female B(6)C(3)F(1) mice when administered for 28 days in the drinking water at concentrations ranging from 2-200 ppm.

  2. Evidence for rapid inter- and intramolecular chlorine transfer reactions of histamine and carnosine chloramines: implications for the prevention of hypochlorous-acid-mediated damage.

    Science.gov (United States)

    Pattison, David I; Davies, Michael J

    2006-07-01

    Hypochlorous acid (HOCl) is a powerful oxidant generated from H(2)O(2) and Cl(-) by the heme enzyme myeloperoxidase, which is released from activated leukocytes. HOCl possesses potent antibacterial properties, but excessive production can lead to host tissue damage that is implicated in a wide range of human diseases (e.g., atherosclerosis). Histamine and carnosine have been proposed as protective agents against such damage. However, as recent studies have shown that histidine-containing compounds readily form imidazole chloramines that can rapidly chlorinate other targets, it was hypothesized that similar reactions may occur with histamine and carnosine, leading to propagation, rather than prevention, of HOCl-mediated damage. In this study, the reactions of HOCl with histamine, histidine, carnosine, and other compounds containing imidazole and free amine sites were examined. In all cases, rapid formation (k, 1.6 x 10(5) M(-)(1) s(-)(1)) of imidazole chloramines was observed, followed by chlorine transfer to yield more stable, primary chloramines (R-NHCl). The rates of most of these secondary reactions are dependent upon substrate concentrations, consistent with intermolecular mechanisms (k, 10(3)-10(4) M(-)(1) s(-)(1)). However, for carnosine, the imidazole chloramine transfer rates are independent of the concentration, indicative of intramolecular processes (k, 0.6 s(-)(1)). High-performance liquid chromatography studies show that in all cases the resultant R-NHCl species can slowly chlorinate N-alpha-acetyl-Tyr. Thus, the current data indicate that the chloramines formed on the imidazole and free amine groups of these compounds can oxidize other target molecules but with limited efficiency, suggesting that histamine and particularly carnosine may be able to limit HOCl-mediated oxidation in vivo. PMID:16800640

  3. Mechanistic chemistry of oxidation of balsalazide with acidic chloramine-T and bromamine-T: A comparative spectrophotometric kinetic study

    Indian Academy of Sciences (India)

    Puttaswamy; S Dakshayani

    2014-11-01

    Balsalazide (BSZ) belongs to a class of non-steroidal anti-inflammatory drugs. Kinetics and mechanism of oxidation of BSZ with sodium N-halo-p-toluenesulfonamides viz., chloramine-T(CAT) and bromamine-T(BAT) in HClO4 medium have been spectrophotometrically investigated (max =357nm) at 303 K. Under comparable experimental conditions, reactions with both the oxidants follow a first-order dependence of rate on [BSZ] and fractional-order dependence on each [oxidant] and [HClO4]. Activation parameters and reaction constants have been computed. 2-hydroxy-5-nitroso-benzoic acid and 3-(4-nitroso-benzoylamino)-propionic acid are identified as the oxidation products of BSZ with both CAT and BAT. The rate of oxidation of BSZ is about five-fold faster with BAT than with CAT. Plausible mechanism and related rate law have been deduced for the observed kinetics.

  4. Impact of pre-ozonation on disinfection by-product formation and speciation from chlor(am)ination of algal organic matter of Microcystis aeruginosa.

    Science.gov (United States)

    Zhu, Mingqiu; Gao, Naiyun; Chu, Wenhai; Zhou, Shiqing; Zhang, Zhengde; Xu, Yaqun; Dai, Qi

    2015-10-01

    The increasing use of algal-impacted source waters is increasing concerns over exposure to disinfection byproducts (DBPs) in drinking water disinfection, due to the higher concentrations of DBP precursors in these waters. The impact of pre-ozonation on the formation and speciation of DBPs during subsequent chlorination and chloramination of algal organic matter (AOM), including extracellular organic matter (EOM) and intracellular organic matter (IOM), was investigated. During subsequent chlorination, ozonation pretreatment reduced the formation of haloacetonitriles from EOM, but increased the yields of trihalomethanes, dihaloacetic acid and trichloronitromethane from both EOM and IOM. While in chloramination, pre-ozonation remarkably enhanced the yields of several carbonaceous DBPs from IOM, and significantly minimized the nitrogenous DBP precursors. Also, the yield of 1,1-dichloro-2-propanone from IOM was decreased by 24.0% after pre-ozonation during chloramination. Both increases and decreases in the bromine substitution factors (BSF) of AOM were observed with ozone pretreatment at the low bromide level (50μg/L). However, pre-ozonation played little impact on the bromide substitution in DBPs at the high bromide level (500μg/L). This information was used to guide the design and practical operation of pre-ozonation in drinking water treatment plants using algae-rich waters.

  5. Short communication: rapid preparation of preventive and therapeutic whole-killed retroviral vaccines using the microbicide taurine chloramine.

    Science.gov (United States)

    Dudani, A K; Martyres, A; Fliss, H

    2008-04-01

    A current urgent priority is to develop microbicides and vaccines to combat retroviruses like human immunodeficiency virus (HIV). We show that the cysteine-selective natural compound, taurine chloramine (T-NCl), can be effective in this task. A number of proteins in all retroviruses contain highly conserved cysteine-rich regions that are essential for infection and replication. Our data show that by targeting these essential cysteine residues, T-NCl (2 or 5 mM) acts as a highly effective and safe microbicide that fully blocks the infectivity of high HIV-1 titers (10(6) TCID(50) units/ml) but is not injurious to eukaryotic cells. We also demonstrate that T-NCl can be used to prepare a highly effective whole-killed vaccine against murine AIDS (MAIDS) that shows both preventive and therapeutic efficacy. The vaccine consists of a T-NCl-inactivated retrovirus suspension in host cell lysate. The novelty of our approach lies in the ease and speed of vaccine preparation and its avoidance of harsh inactivation or purification steps that can alter native viral conformation. Our approach is therefore likely to overcome a number of intractable obstacles to the preparation of an effective whole-killed HIV vaccine, such as surviving infective viral particles, rapid viral mutation rates, numerous viral strains, and harsh purification steps. Our approach may also permit the rapid preparation of autologous, or custom-made, vaccines for individual patients.

  6. Histopathology of repeated, intermittent exposure of chloramine-T to walleye (Sander vitreum) and (Ictalurus punctalus) channel catfish

    Science.gov (United States)

    Gaikowski, M.P.; Densmore, Christine L.; Blazer, V.S.

    2009-01-01

    Chloramine-T (Cl-T) has been used safely and effectively to control bacterial gill disease in salmonids at a maximum exposure regimen of up to four consecutive, once-daily exposures administered for 60??min at 20??mg/L. However, data to document safe treatment concentrations of Cl-T are lacking for freshwater-reared fish other than salmonids. We report the histopathology resultant from the administration of 12 consecutive, once-daily, 180-min static immersion baths of 0, 20, 50, or 80??mg Cl-T/L to walleye (20????C) and channel catfish (27????C). Twelve fish of each species were euthanized immediately before the first exposure (initial controls) and then after the twelfth exposure and 7 and 14??days after the twelfth exposure. Only initial controls and fish euthanized immediately after the twelfth exposure were processed for histological review because of the general lack of exposure-related lesions in exposed fish. The only exposure-related histological changes were in the spleen where significantly greater erythrocyte swelling and necrosis was observed in channel catfish exposed at 80??mg/L relative to exposure at 0??mg/L; similar histological changes were insignificant for walleye, though there appeared to be a shift in the general category of histological change with degenerative changes (necrosis, etc.) observed following exposure at 50 or 80??mg/L compared to the inflammatory and hemodynamic changes (congestion, leukocyte infiltrate, etc.) observed in walleye exposed at 0 or 20??mg/L. The only significant change in peripheral blood cytology was that walleye fingerlings exposed at 80??mg/L had significantly fewer mature red blood cells and significantly more immature red blood cells per oil-immersion field than controls. The histopathological changes observed following exposure to Cl-T under an exaggerated exposure regimen suggest that walleye or channel catfish therapeutically exposed to Cl-T will not have treatment-related histological changes.

  7. Influence of chloramine T iodination on the biological and immunological activity or the molecular radius of the human growth hormone molecule

    International Nuclear Information System (INIS)

    Potential alterations of the somatotropic activity of human growth hormone (hGH) resulting from Chloramine T labelling reaction, iodination up to 2.7 atoms/molecule and indirect radiation effects, have been studied. Three 2X2 factorial assays, performed in hypophysectomized rats, failed to reveal any significant difference (P greater than 0.05) in true growth promoting activity between hGH and (127-I)hGH, even after storing the latter with 125-I. Similar results were obtained applying a sensitive and precise gel filtration technique for Stokes Radius determination and radioimmunoassay

  8. Identification, toxicity and control of iodinated disinfection byproducts in cooking with simulated chlor(am)inated tap water and iodized table salt.

    Science.gov (United States)

    Pan, Yang; Zhang, Xiangru; Li, Yu

    2016-01-01

    Chlorine/chloramine residuals are maintained in drinking water distribution systems to prevent microbial contamination and microorganism regrowth. During household cooking processes (e.g., soup making), the residual chlorine/chloramines in tap water may react with the iodide in iodized table salt to form hypoiodous acid, which could react with remaining natural organic matter in tap water and organic matter in food to generate iodinated disinfection byproducts (I-DBPs). However, I-DBPs formed during cooking with chloraminated/chlorinated tap water are almost completely new to researchers. In this work, by adopting precursor ion scan of m/z 127 using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, many new polar I-DBPs formed during cooking with chloraminated/chlorinated tap water were detected and proposed with structures, of which 3-iodo-4-hydroxybenzaldehyde, 3-iodo-4-hydroxybenzoic acid, 3-iodo-4-hydroxy-5-methylbenzoic acid, diiodoacetic acid, 3,5-diiodo-4-hydroxybenzaldehyde, 3,5-diiodo-4-hydroxybenzoic acid, 2,6-diiodo-4-nitrophenol, 2,4-diiodo-6-nitrophenol, and 2,4,6-triiodophenol were confirmed with standard compounds. With the aid of ultra fast liquid chromatography/ion trap-time of flight-mass spectrometry, molecular formula identification of five new I-DBPs (C8H5O4I, C7H4NO4I, C8H5O5I, C7H4NO5I, and C8H6O3I2) was achieved. A developmental toxicity with a recently developed sensitive bioassay was conducted for the newly identified I-DBPs, suggesting that phenolic I-DBPs (except for iodinated carboxyphenols) were about 50-200 times more developmentally toxic than aliphatic I-DBPs. The major I-DBPs in a baseline simulated cooking water sample were determined to be from 0.72 to 7.63 μg/L. Polar I-DBPs formed under various disinfection and cooking conditions were compared, and suggestions for controlling their formation were provided. PMID:26474150

  9. Identification, toxicity and control of iodinated disinfection byproducts in cooking with simulated chlor(am)inated tap water and iodized table salt.

    Science.gov (United States)

    Pan, Yang; Zhang, Xiangru; Li, Yu

    2016-01-01

    Chlorine/chloramine residuals are maintained in drinking water distribution systems to prevent microbial contamination and microorganism regrowth. During household cooking processes (e.g., soup making), the residual chlorine/chloramines in tap water may react with the iodide in iodized table salt to form hypoiodous acid, which could react with remaining natural organic matter in tap water and organic matter in food to generate iodinated disinfection byproducts (I-DBPs). However, I-DBPs formed during cooking with chloraminated/chlorinated tap water are almost completely new to researchers. In this work, by adopting precursor ion scan of m/z 127 using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, many new polar I-DBPs formed during cooking with chloraminated/chlorinated tap water were detected and proposed with structures, of which 3-iodo-4-hydroxybenzaldehyde, 3-iodo-4-hydroxybenzoic acid, 3-iodo-4-hydroxy-5-methylbenzoic acid, diiodoacetic acid, 3,5-diiodo-4-hydroxybenzaldehyde, 3,5-diiodo-4-hydroxybenzoic acid, 2,6-diiodo-4-nitrophenol, 2,4-diiodo-6-nitrophenol, and 2,4,6-triiodophenol were confirmed with standard compounds. With the aid of ultra fast liquid chromatography/ion trap-time of flight-mass spectrometry, molecular formula identification of five new I-DBPs (C8H5O4I, C7H4NO4I, C8H5O5I, C7H4NO5I, and C8H6O3I2) was achieved. A developmental toxicity with a recently developed sensitive bioassay was conducted for the newly identified I-DBPs, suggesting that phenolic I-DBPs (except for iodinated carboxyphenols) were about 50-200 times more developmentally toxic than aliphatic I-DBPs. The major I-DBPs in a baseline simulated cooking water sample were determined to be from 0.72 to 7.63 μg/L. Polar I-DBPs formed under various disinfection and cooking conditions were compared, and suggestions for controlling their formation were provided.

  10. Effects of sub lethal concentration of Chloramin T on growth, survival, haematocrit and some blood biochemical parameters in common carp fry (Cyprinus carpio

    Directory of Open Access Journals (Sweden)

    Mohamad R. Imanpoor

    2011-07-01

    Full Text Available This study was done in Gorgan University of Agricultural Sciences and Natural Resources, in 2009, during 8 weeks to survey effects of different concentrations of Chloramin T on fry common carp (Cyprinus carpio (Linnaeus, 1758. According to the pre experiment data, lethal concentration, the lowest observed effect concentration, maximum allowable toxicant concentration and No Observed Effect Concentration of Chloramin T (Halamid in common carp (C. carpio fry were respectively 40.9, 27.1, 4.90 and 11.28 mg/L-1. Hence, the range of our experiment was between 0 to 25 mg L-1 which was divided to five treatments (0, 5, 10, 15 and 25 mg/L-1. At the end of experiment we calculated growth factor (special growth rate and food conversion ratio and stress indices (glucose total protein and percent of haematocrit and then they were compared with the controlled group. Our study results showed no significant difference between percentage of increase in body weight (280.4±25.79 - 200.4±10.16, special growth rate (2.34±0.25 - 1.96±0.06 and food conversion ratio (0.84±0.05 - 0.60±0.12 in experimental lots of fishes. There is also no significant difference between glucose (146.82±0.79 - 99.54±1.89 and total protein (3.61±0.45 - 2.82±0.06 in experimental groups (P>.05. However there is a significant difference between the percentages of haematocrit (57.34±4.99 - 40.74±2.17 and cholesterol (362.05±24.38 - 134.92±17.59 in these groups (P<0.05.

  11. Fluorous Analogue of Chloramine-T: Preparation, X-ray Structure Determination, and Use as an Oxidant for Radioiodination and s-Tetrazine Synthesis.

    Science.gov (United States)

    Dzandzi, James P K; Beckford Vera, Denis R; Genady, Afaf R; Albu, Silvia A; Eltringham-Smith, Louise J; Capretta, Alfredo; Sheffield, William P; Valliant, John F

    2015-07-17

    A fluorous oxidant that can be used to introduce radioiodine into small molecules and proteins and generate iodinated tetrazines for bioorthogonal chemistry has been developed. The oxidant was prepared in 87% overall yield by combining a fluorous amine with tosyl chloride, followed by chlorination using aqueous sodium hypochlorite. A crystal structure of the oxidant, which is a fluorous analogue of chloramine-T, was obtained. The compound was shown to be stable for 7 days in EtOH and for longer than three months as a solid. The oxidant was effective at promoting the labeling of arylstannanes using [(125)I]NaI, where products were isolated in high specific activity in yields ranging from 46% to 86%. Similarly, iodinated biologically active proteins (e.g., thrombin) were successfully produced, as well as a radioiodinated tetrazine, through a concomitant oxidation-halodemetalation reaction. Because of its fluorous nature, unreacted oxidant and associated reaction byproducts can be removed quantitatively from reaction mixtures by passing solutions through fluorous solid phase extraction cartridges. This feature enables rapid and facile purification, which is critical when working with radionuclides and is similarly beneficial for general synthetic applications. PMID:26030355

  12. Influence of Natural Organic Matter (NOM) Character on the Distribution of Chlorinated and Chloraminated Disinfection By-Products (DBPs) at Rand Water

    Science.gov (United States)

    Marais, Savia S.; Ncube, Esper J.; Haarhoff, Johannes; Msagati, Titus AM; Mamba, Bhekie B.; Nkambule, Thabo I.

    2016-04-01

    Certain disinfection by-products (DBPs) are likely human carcinogens or present mutagenic effects while many DBPs are unidentified. Considering the possibility of DBPs being harmful to human health and the fact that trihalomethanes (THMs) are the only regulated DBP in the South African National Standard (SANS:241) for drinking water, special interest in the precursors to these DBPs' formation is created. It is essential to understand the reactivity and character of the precursors responsible for the formation of DBPs in order to enhance precursor removal strategies during the treatment of drinking water. In this study the character of NOM within surface water and the subsequent distribution of THMs formed in the drinking water from Rand Waters' full scale treatment plant were investigated. Molecular size distribution (MSD) of NOM within the surface water was determined by high performance size exclusion chromatography (HPSEC). Specific ultraviolet absorbance (SUVA) and UV254 measurements formed part of the NOM character study as they provide an indication of the aromaticity of organic matter. The four THMs; bromoform, chloroform, dibromochloromethane (DBCM) and bromodichloromethane (BDCM)were measured by gas chromatography. The sum of these four THMs was expressed as total trihalomethane (TTHM). On average the chloroform constituted 76.2% of the total TTHM, BDCM 22.5% while DBCM and bromoform measured below the detection limit. THM speciation after chlorination and chloramination concentrations increased in the sequence bromoform water in summer when high temperatures and rainfall occurred. The results displayed are an indication that aromatic NOM were the main precursor to TTHM formation, more prominently during summer. Keywords: disinfection by-products, molecular size distribution, natural organic matter, UV254

  13. Surto de reações hemolíticas associado a residuais de cloro e cloraminas na água de hemodiálise Outbreak of hemolytic reactions associated with chlorine and chloramine residuals in hemodialysis water

    Directory of Open Access Journals (Sweden)

    Rachel VV Calderaro

    2001-10-01

    Full Text Available OBJETIVO: Relatar o processo de investigação da contaminação da água e a conseqüente avaliação do surto ocorrido no serviço de hemodiálise. MÉTODOS: Em setembro de 2000, 16 pacientes sob terapia de hemodiálise de um hospital em Minas Gerais apresentaram reações hemolíticas compatíveis a sintomas de intoxicação por cloro e cloramina em água. Foi feita a medição das concentrações de cloro e cloramina em amostras coletadas em diversos pontos do sistema de tratamento e distribuição de água do serviço inspecionado. A identificação dos casos ocorridos durante o período de estudo foi feita pela revisão das anotações de prontuários dos pacientes. Foi feita a revisão dos procedimentos da equipe técnica, médica e de enfermagem por meio de entrevistas. RESULTADOS: A taxa de sintomas foi significativamente alta (pOBJECTIVE: To investigate the process of water contamination and to assess the subsequent outbreak in the hemodialysis center. METHODS: In September 2000, sixteen patients undergoing chronic hemodialysis at a dialysis center in Minas Gerais, Brazil, experienced hemolytic reactions compatible with toxic symptoms due to chlorine and chloramine water contamination. Chlorine and chloramine concentrations in samples obtained from various sites of the dialysis center's water treatment and distribution system were measured. Case-patients were identified by reviewing medical records and nursing notes for all dialysis sessions carried out during the study period. Interviews with technicians, nursing and medical staff members were conducted. RESULTS: Reaction rate was significantly higher (p£0.5 mg/L for chlorine and £ 0.1 mg/L for chloramine. Individuals exposed to high chlorine and chloramine concentrations presented a relative risk of 2.58 (1.0-6.28 of having hemolytic reactions. CONCLUSION: There is a need to observe surveillance procedures to secure that the maximum allowable concentrations of regulated substances

  14. 氯胺消毒过程中碘代三卤甲烷生成的影响因素%Factors Affecting Iodo-trihalomethane Formation during Chloramination of Micro-polluted Raw Water

    Institute of Scientific and Technical Information of China (English)

    孙仲昊; 徐斌; 胡晨燕; 夏圣骥; 高乃云; 叶涛

    2013-01-01

    碘代消毒副产物的“三致”特性远高于氯代和溴代消毒副产物,是近年来饮用水领域颇受关注的一类新兴消毒副产物.以微污染原水为研究对象,系统研究了其在氯胺消毒条件下碘代三卤甲烷类消毒副产物生成的影响因素.研究发现,在原水中存在一定浓度碘离子的条件下,采用氯胺消毒可产生较高浓度的碘代三卤甲烷类消毒副产物,其中以三碘甲烷为主;碘代三卤甲烷的生成总量随着反应时间的增加而增加;碘代三卤甲烷的生成量和组成受氯胺投加量的影响较大,在氯胺投加量较低的情况下主要生成三碘甲烷和一溴二碘甲烷,在氯胺投加量较高的情况下生成一氯二碘甲烷、二氯一碘甲烷、一溴二碘甲烷和三碘甲烷四种碘代三卤甲烷;碘代三卤甲烷的生成总量以及三碘甲烷在总碘代三卤甲烷中的比例随着碘离子浓度的增加而提高;总体上,氯胺化过程中碘代三卤甲烷的生成总量随着pH值的升高而增加.%Iodinated disinfection byproducts contain higher mutagenesis, carcinogenesis and terat-ogenesis than chlorinated and brominated disinfection byproducts. Increasing attention is focused on these emerging byproducts in the drinking water field recently. The factors affecting iodo-trihalomethane formation during chloramination of micro-polluted raw water were investigated. The results showed that higher concentrations of iodo-trihalomethanes would be produced during chloramination in the presence of iodide in raw water, in which iodoform was predominant. The total amount of iodo-trihalomethanes increased with reaction time, and the total amount and species of iodo-trihalomethanes were influenced by chlora- mine dosage. Iodoform and bromodiiodomethane were generated by a relatively low chloramine dosage. With high chloramine dosage, four kinds of iodo-trihalomethanes including chlorodiiodomethane, di-chloroiodomethane, bromodiiodomethane

  15. 粉末炭-超滤工艺出水氯和氯胺消毒安全性评价%Safety evaluation of chlorine and chloramine disinfection with treated water of PAC-UF treatment process

    Institute of Scientific and Technical Information of China (English)

    杨艳玲; 奚璐翊; 李星; 黄静

    2011-01-01

    考察了粉末炭-超滤工艺(PAC-UF)除污染效果,以及膜后出水氯和氯胺消毒对微生物再生长的控制与消毒副产物的生成情况,对水质安全性进行综合评价.结果表明:PAC-UF工艺能够高效截留水中胶体及致病微生物;对氨氮、高锰酸盐指数(CODMn)、254nm处的紫外吸光度(UV254)和溶解性有机碳(DOC)的平均去除率分别为36.04%,44.28%,44.94%和30.65%;在不消毒情况下,膜后出水在24h后均出现微生物再生长;氯胺对微生物持续抑制能力强于氯;所生成的THMs与HAAs分别比氯消毒降低63.42%和44.13%,并有效减少了溴代消毒副产物的生成量;PAC-UF工艺出水采用氯胺消毒可使水质的安全性均得到提高.%Pollutants removal effects of powdered activated carbon-ultrafiltration(PAC-UF) treatment process was examined.Disinfection effect of chlorine and chloramines were compared on control of microbe regrowth and disinfection by-products formation.The safety of treated water of the PAC-UF treatment process was comprehensively evaluated.The results show that colloids and pathogenic microbes can be removed efficiently by the PAC-UF treatment process.Average removal rates of ammonium,CODMn(chemical oxygen demand),UV254(ultraviolet in 254 nm) and DOC(disolved organic carbon) are 36.04%,44.28%,44.94% and 30.65% respectively.The bacteria and coliform index of the water samples appears significantly regrowth after 24 h without disinfection.Chloramine has better continuous disinfection effects than chlorine′s effects on inactivation of microbe and maintenance of residual chlorine.The THMs(trihalomethanes) and HAAs(haloacetic acids) produced by chloramine disinfection are lowered 63.42% and 44.13% than by chlorine disinfection respectively,and formation of brominated disinfection by-products is decreased effectively too.Safeties of treated water by PAC-UF treatment process can be enhanced by chloramines.

  16. Effect of Chloramine Auxiliary Disinfection and Organic Halide Content Change in Drinking Water%饮用水氯胺辅助消毒的效果及有机卤化物含量变化

    Institute of Scientific and Technical Information of China (English)

    李为兵; 陈雪芳; 袁哲; 陈卫

    2011-01-01

    Compared with chlorine disinfection, chloramine disinfection can effectively reduce the formation of disinfection byproducts.After chlorination in clear water tank, chloramine is used as auxiliary disinfectant to maintain the water quality in water distribution network in Kunshan City.The qualified rate of water quality at monitoring points rises from 92.8% to 99.5%, and the disinfection effect in water distribution network is distinctly improved.When the organic content is high, using chloramine auxiliary disinfection can reduce adsorbable organic halogens in drinking water by 48% comparing with the chlorine disinfection.Under the premise of ensuring the disinfection effect of treated water and water in clear water tank, the chlorine dosage in clear water tank should be reduced as far as possible to control the chlorine disinfection byproduct at a low level.Through the analysis of content of disinfection byproducts,such as trihalomethanes, chlorobenzene and haloacetic acids, it is confirmed that the chloramine disinfection may largely reduce the organic halide content in drinking water, which is consistent with the determination result of adsorbable organic halogen compounds.%与氯消毒相比,氯胺消毒能有效降低消毒副产物的生成量.昆山市在水厂清水池加氯消毒后,将氯胺用作维持管网水质的辅助消毒剂,使管网水质监测点的消毒剂余量和细菌总数合格率从92.8%上升到99.5%,管网消毒效果得到明显改善.在有机物含量较高的情况下,与氯消毒相比,采用氯胺辅助消毒可降低饮用水中可吸附有机卤素(AOX)含量达48%,因而在保证清水池和出厂水消毒效果的前提下,应尽量降低清水池的投氯量,以使氯消毒副产物含量控制在较低水平.通过对三卤甲烷、氯苯和卤乙酸等氯化消毒副产物含量的测定分析,证实氯胺消毒可大幅降低饮用水中的有机卤化物含量,这与对可吸附有机卤素的测定结果是一致的.

  17. 南水北调丹江口水库水氯(胺)化消毒副产物产生特性与消毒工艺对比%Formation of Disinfection By-Products During Chlor(am)ination of Danjiangkou Reservoir Water and Comparison of Disinfection Processes

    Institute of Scientific and Technical Information of China (English)

    张民盛; 徐斌; 张天阳; 程拓; 夏圣骥; 楚文海

    2015-01-01

    This study discussed the formation of volatile carbonaceous disinfection by-products (DBPs) and nitrogenous DBPs during chlor(am)ination of Danjingkou Reservoir water which was the source of the middle Route Project of South-to-North Water Diversion Project. The effects of disinfection methods, disinfectant dosage, reaction time, pH values and bromide ion concentration were investigated. And the disinfection parameters were optimized. Four DBPs, including chloroform ( CF), bromodichloromethane (BDCm), dichloroacetonitrile(DCAN) and trichloronitromethane(TCNm) , were observed during the chlorination. But only CF and TCNm were detected during the chloramination of water. The disinfection by-product (DBP) concentration from chlorination is 7. 5 times higher than that from chloramination, and the yield of DBPs from short time chlorination then chloramination is in between the first two methods. All kinds of DBPs detected increased with the dosage of increasing chlorine, but the increases slowed down when the dosage was higher than 2 mg·L - 1 . The formation of CF varied a little as the dosage of chloramine increasing. TCNm was detected when the chloramine dosage was greater than 2 mg·L - 1 . As reaction time going on, chlorine decayed much faster than chloramine, while DBP formation under chlorination was faster than that of chloramination. THm produced by chlorine increased with the increasing pH, while chloramination showed no obvious changes. As the bromide ion increasing, the species of DBPs transformed from chlorinated DBPs to brominated ones, and the total yield of DBPs increased during both chlorination and chloramination, but the former one was obviously more than that of the latter one. In order to reduce the risk of DBP formation, the chloramination is suggested in the treatment of water from Danjiangkou Reservoir. And if chlorination is applied, the disinfectant dosage should be controlled seriously.%系统研究了南水北调中线工程水源---丹江

  18. 顺序投加联合消毒剂二氧化氯氯胺对饮用水中消毒副产物的控制%Control of Disinfection Byproducts (DBPs)in Drinking Water by Sequential Dosing of Joint Disinfection with Chlorine Dioxide and Chloramine

    Institute of Scientific and Technical Information of China (English)

    易芳; 吴立波; 杨林锋; 叶竹兰; 万芬

    2015-01-01

    Traditional chlorine disinfection process has attracted wide attention because of its harmful disinfection byproducts. The control of disinfection byproducts in drinking water by sequential dosing of joint disinfectants with dioxide and chloramine was investigated in this study. The raw water was taken from filtration water in a waterworks in Tianjin,which was disinfected by the different doses combination of chlorine dioxide and chloramine. The results show that when dosage of chlorine dioxide is 0. 10 ~0. 50 mg / L and chloramine is 0. 50 ~ 1. 50 mg / L,the generation of disinfection byproducts can be effectively controlled,which meets the requirements of relevant standards.%传统氯消毒工艺因易生成对人体有害的消毒副产物被广泛关注,采用替代氯消毒工艺控制消毒副产物是目前的研究重点。该文以天津市某自来水厂滤后水为试验对象,采用二氧化氯氯胺顺序投加联合消毒工艺,分析了不同投加量组合对消毒副产物( THMs,HAAs和亚氯酸盐)产量的控制情况。结果表明当二氧化氯投加量为0.10~0.50 mg / L、氯胺投加量为0.50~1.50 mg / L时,消毒副产物的生成量均能得到有效控制,符合相关标准的要求。

  19. Use of chloramine-T and two dyes in the sensitive determination of stavudine in pharmaceuticals Uso de cloramina-T e de dois corantes na determinação sensível de estavudina em medicamentos

    Directory of Open Access Journals (Sweden)

    Kanakapura Basavaiah

    2007-09-01

    Full Text Available Three new methods are described for the assay of stavudine (STV in bulk drug and in dosage forms using chloramine-T (CAT and two dyes, methyl orange and indigocarmine, as reagents. Titrimetry involves treating STV with a measured excess of CAT in hydrochloric acid medium, and after the oxidation of STV is judged to be complete, the unreacted oxidant is determined iodometrically. Spectrophotometric methods entail the addition of a known excess of CAT to STV in hydrochloric acid medium followed by determination of residual oxidant by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A or indigo carmine and measuring the absorbance at 610 nm (Method B. In all the methods, the amount of CAT reacted corresponds to the amount of STV. In titrimetric method, the reaction follows 1:1 stoichiometry (STV: CAT, and is applicable over the range 1.5-10 mg of STV. In spectrophotometric methods, the absorbance is found to increase linearly with concentration of STV. The systems obey Beer's law for 0.2-2.0 and 1.0-10.0 mg/mL for method A and method B, respectively. The apparent molar absorptivities are calculated to be 5.7x10(4 and 1.5x10(4 L/mol/cm for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.004 and 0.015 µg/cm². The limits of detection and quantification are reported for both methods. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the assay of STV in tablet and capsule formulations and the results were compared with those of a reference method by applying Student's t-test and F-test. No interference was observed from common tablet adjuvants. The accuracy and reliability of the methods were further ascertained by performing recovery experiments via standard-addition method.Descrevem-se três novos métodos para o ensaio de estavudina (STV na mat

  20. Distribution of disinfection by-product formation potential by chlor(am)ination in three megalopolis along Yangtze river%长江沿线城市水源氯(胺)化消毒副产物生成潜能研究

    Institute of Scientific and Technical Information of China (English)

    黄河; 徐斌; 朱文倩; 秦朗; 马玉英

    2014-01-01

    Dissolved organic matter (DOM) in raw water from upper Yangtze River in Chongqing, middle Yangtze River in Wuhan, lower Yangtze River in Shanghai was isolated into fractions with different hydrophobicity and molecular weight (MW) by resin adsorption and ultra-filtration, respectively, to investigate and regulate emerging disinfection byproducts formation potential during chlorination and chloramination for each fraction. Research showted that DOM from Chongqing, Wuhan and Shanghai was mainly constituted of MW<1kDa organic compounds, hydrophilic and hydrophobic fractions. Trihalometheanes, haloketones, haloacetic acids, haloacetonitriles and chloropicrin were formed after chlorination and chloramination. Among three cities, MW<1kDa fractions gave the highest yield of carbonaceous disinfection byproducts (C-DBPs) and nitrogenous disinfection byproducts (N-DBPs), and the proportion of MW<1kDa formation potential tended to ascend from the upper Yangtze River to lower Yangtze River;Among all three megalopolis, hydrophobic fraction and hydrophilic fraction produced more C-DBPs and N-DBPs, the proportion of hydrophilic fraction C-DBPs and N-DBPs formation potential tended to ascend during chloramination.%以长江上游重庆、中游武汉、下游上海等大城市的长江饮用水源为研究对象,在对溶解性有机物分子量和亲疏水性分离的基础上,分别采用氯和氯胺两种方式消毒,对比分析了相同时期沿江这些城市原水中氯(胺)化常规和新兴含氮消毒副产物生成潜能的分子组成规律。研究表明,重庆、武汉、上海三地的溶解性有机物均以小分子前体物为主,主要分布在<1kDa 的区间内,且以强疏水性成分和亲水性成分为主,原水经氯(胺)化可产生三卤甲烷、卤乙酸、卤乙腈、三氯硝基甲烷等类型的消毒副产物;三地的氯(胺)化主要的含碳消毒副产物(C-DBPs)和含氮消毒副产物(N-DBPs)生成潜能均在<1kDa的区间内

  1. Effect of pH and Temperature on Nitrification in a Bench-Scale Drinking Water Distribution System During Chloramination%pH和温度对氯胺消毒给水管网硝化作用的影响

    Institute of Scientific and Technical Information of China (English)

    周玲玲; 张永吉; 宋正国; 曾果; 叶河秀; 高乃云; 李圭白

    2011-01-01

    采用生物膜培养反应器(RAB)模拟给水管网系统,研究了pH和温度对硝化作用的影响.结果表明,较低水温(15℃)对硝化作用的影响不明显,而在较高水温(30℃)下模拟管网中明显地发生了硝化作用.较低水温(15℃)下,提高水的pH对硝化作用的影响较小,而在较高水温(30℃)情况下提高水的pH对硝化作用具有明显的控制效果.在较高水温时,pH由7.5±0.22提高到9.3±0.24,反应器中余氯胺浓度平均升高0.76 mg/L,生物膜和出水中的氨氧化细菌(AOB)浓度分别降低0.6 lgMPN/cm和1.4 lg MPN/mL,水中异养细菌降低98 CFU/mL.2种pH条件下反应器出水亚硝酸氮浓度较进水分别提高4倍和3倍.而在较低水温(15℃)条件下,pH由7.4±0.15提高到9.3±0.26时,反应器出水氯胺浓度、亚硝酸氮和氨氮浓度变化都不大,水中异养细菌浓度稳定.%The effect of pH and temperature on the controlling of nitrification was evaluated using rotating annular bioreactors (RABs),which were applied to simulate the drinking water distribution system. The results showed that elevated pH had little effect on nitrification occurrence at low temperature ( 15℃ ), however the pH controlling effect on nitrification was obvious at high temperature (30℃). With pH increasing from 7.5 ± 0. 22 to 9.3 ± 0. 24 at high temperature (30℃), the residual chloramines concentration increased to 0. 76 mg/L, and the AOB concentration in the biofilm and bulk water reduced 0. 6 lg MPN/cm2 and 1.4 lg MPN/mL respectively, the heterotrophic bacteria concentration in bulk water reduced 98 CFU/mL. With pH increasing from 7.4 ± 0. 15 to 9.3 ±0. 26, compared with the influent nitrite concentration, the effluent nitrite concentration increased four and three times respectively at different pH levels. The effluent residual chloramines, nitrite nitrogen, ammonia nitrogen concentrations varied slightly compared with influent at low temperature ( 15℃ ), and the effluent

  2. Chlorine, Chloramine, Chlorine Dioxide, and Ozone Susceptibility of Mycobacterium avium

    OpenAIRE

    Taylor, Robert H.; Joseph O. Falkinham; Norton, Cheryl D.; LeChevallier, Mark W.

    2000-01-01

    Environmental and patient isolates of Mycobacterium avium were resistant to chlorine, monochloramine, chlorine dioxide, and ozone. For chlorine, the product of the disinfectant concentration (in parts per million) and the time (in minutes) to 99.9% inactivation for five M. avium strains ranged from 51 to 204. Chlorine susceptibility of cells was the same in washed cultures containing aggregates and in reduced aggregate fractions lacking aggregates. Cells of the more slowly growing strains wer...

  3. EFFECT OF CHLORAMINATION AND SEASONAL WATER CHANGES ON NANOFILTRATION FOULING

    Science.gov (United States)

    Nanofiltraton membrane studies conducted with Little Miami Aquifer water from the Indian Hill Water Works (OH) showed tht flux loss was highly seasonal in nature with the greatest fouling occurring during the highest water temperatures during drought conditions. The reason for th...

  4. Preparation of iodine - 125 - labeled insulin for radioimmunoassay: comparison of chloramine T and iodogen iodination

    International Nuclear Information System (INIS)

    Stoichiometric iodination of porcine insulin was performed to the general method of Hunter and Greenwood with modifications recommended by Roth. These method was compared with radioidination using Iodogen. Films of Iodogen react rapidly in the solid phase with aqueous mixtures of I -and proteins. For two methods satisfactory activity of the labeled porcine insulin was obtained and characteristics of the radioimmunoassay were studied. (author)

  5. Reconsidering Lead Corrosion in Drinking Water: Product Testing, Direct Chloramine Attack and Galvanic Corrosion

    OpenAIRE

    Dudi, Abhijeet

    2004-01-01

    The ban on lead plumbing materials in the Safe Drinking Water Act (1986) and the EPA Lead and Copper Rule (1991) have successfully reduced lead contamination of potable water supplies. The success of these regulations gave rise to a belief that serious lead contamination was an important past problem that had been solved, and that additional fundamental research was therefore unnecessary. This work carefully re-examined the lead contamination issue from the perspective of 1) new regulation...

  6. Biofilm Community Dynamics in Bench-Scale Annular Reactors Simulating Arrestment of Chloraminated Drinking Water Nitrification

    Science.gov (United States)

    Annular reactors (ARs) were used to study biofilm community succession and provide an ecological insight during nitrification arrestment through simultaneously increasing monochloramine (NH2Cl) and chlorine to nitrogen mass ratios, resulting in four operational periods (I to IV)....

  7. Changes in physicochemical and transport properties of a reverse osmosis membrane exposed to chloraminated seawater.

    Science.gov (United States)

    Valentino, Lauren; Renkens, Tennie; Maugin, Thomas; Croué, Jean-Philippe; Mariñas, Benito J

    2015-02-17

    This study contributed to improving our understanding of how disinfectants, applied to control biofouling of reverse osmosis (RO) membranes, result in membrane performance degradation. We investigated changes in physicochemical properties and permeation performance of a RO membrane with fully aromatic polyamide (PA) active layer. Membrane samples were exposed to varying concentrations of monochloramine, bromide, and iodide in both synthetic and natural seawater. Elemental analysis of the membrane active layer by Rutherford backscattering spectrometry (RBS) revealed the incorporation of bromine and iodine into the polyamide. The kinetics of polyamide bromination were first order with respect to the concentration of the secondary oxidizing agent Br2 for the conditions investigated. Halogenated membranes were characterized after treatment with a reducing agent and heavy ion probes to reveal the occurrence of irreversible ring halogenation and an increase in carboxylic groups, the latter produced as a result of amide bond cleavage. Finally, permeation experiments revealed increases in both water permeability and salt passage as a result of oxidative damage.

  8. Changes in physicochemical and transport properties of a reverse osmosis membrane exposed to chloraminated seawater

    KAUST Repository

    Valentino, Lauren

    2015-02-17

    This study contributed to improving our understanding of how disinfectants, applied to control biofouling of reverse osmosis (RO) membranes, result in membrane performance degradation. We investigated changes in physicochemical properties and permeation performance of a RO membrane with fully aromatic polyamide (PA) active layer. Membrane samples were exposed to varying concentrations of monochloramine, bromide, and iodide in both synthetic and natural seawater. Elemental analysis of the membrane active layer by Rutherford backscattering spectrometry (RBS) revealed the incorporation of bromine and iodine into the polyamide. The kinetics of polyamide bromination were first order with respect to the concentration of the secondary oxidizing agent Br2 for the conditions investigated. Halogenated membranes were characterized after treatment with a reducing agent and heavy ion probes to reveal the occurrence of irreversible ring halogenation and an increase in carboxylic groups, the latter produced as a result of amide bond cleavage. Finally, permeation experiments revealed increases in both water permeability and salt passage as a result of oxidative damage.

  9. The effect of taurine chloramine on human osteosarcoma cell-lines

    International Nuclear Information System (INIS)

    Osteosarcoma is the most frequent nonhaematogenic primary malignant tumor of the bone. The rather rare tumour occurs mainly in children and adolescents. This osteogenic tumour is a high-aggressive mesenchymal neoplasm typically producing osteoid. The surgical resection of the complete tumour must be carried out with wide or radical margins to prevent recurrence. Even though the combination of surgery with chemotherapy has noticeably improved the survival rate of osteosarcoma patients, the application of anticancer drugs is still associated with significant adverse reactions, for example the common acquisition of drug-resistant phenotypes, indicating the need of new chemotherapeutical substances. Taurine is a sulfur-containing β-amino acid, which is present in high concentrations in mammalian cells and plasma, in granulocytes and lymphocytes. Large quantities of taurine are released by stimulated neutrophiles and rapidly chlorinated by the reaction with hypochlorous acid (HOCl) generating taurine monochloramine (NCT). NCT is noted to play quite a few roles in the modulation of the immune response and sizeably decreases the production of plenty proinflammatory mediators from adherent as well as non-adherent leucocytes. NCT inhibits the intracellular transcription of nitric-oxide synthase and the production of nitric oxide and switches cell death from the less advantageous necrosis to the more physiologically beneficial apoptosis. Aim of this study was to research, if different concentrations of NCT are capable to induce apoptosis in the human osteosarcoma cell lines HOS, MG-63 and SAOS-2. Therefore the cell proliferation assay EZ4U, a fluorescence staining with acridine-orange, an ELISA for the detection of DNA-fragments and a JC-1 mitochondrial FACS-analysis were performed. The results of these four independent experiments show, that NCT has a pro-apoptotic effect on these osteosarcoma cell lines. (author)

  10. Integrated Chemical and Toxicological Investigation of UV-Chlorine/Chloramine Drinking Water Treatment

    Science.gov (United States)

    As the use of alternative drinking water treatment increases, it is important to understand potential public health•implications associated with these processes. The objective of this study was to evaluate the formation of disinfection byproducts (DBPs) and cytotoxicity of ...

  11. [First results on the use of chloramines to reduce disinfection byproducts in drinking water].

    Science.gov (United States)

    Azara, Antonio; Muresu, Elena; Dettori, Marco; Ciappeddu, Pierluigi; Deidda, Antonio; Maida, Alessandro

    2010-01-01

    The presence of disinfection byproducts (DBP) in drinking water raises concerns about the safety of chlorination and is one of the problems inherent the use of surface water as a source of drinking water. In order to reduce the presence of DBP (in particular of chlorites), we evaluated the combined use of chlorine dioxide for primary disinfection and monochloramine for residual disinfection in a water purification plant and distribution system in Sardinia (Italy). The results are very encouraging. Disinfection byproducts were reduced and other parameters were found to be within the recommended standards, indicating further improvements of the purification process.

  12. Characterization of chlorinated and chloraminated drinking water microbial communities in a distribution system simulator using pyrosequencing data analysis

    Science.gov (United States)

    The molecular analysis of drinking water microbial communities has focused primarily on 16S rRNA gene sequence analysis. Since this approach provides limited information on function potential of microbial communities, analysis of whole-metagenome pyrosequencing data was used to...

  13. KINETICS OF OXIDATION OF SALBUTAMOL BY CHLORAMINE-B IN NaOH MEDIUM: A MECHANISTIC APPROACH

    Directory of Open Access Journals (Sweden)

    Iyengar Pushpa

    2012-04-01

    Full Text Available The kinetics of oxidation of salbutamol (SBL by N-chlorobenzenesulphonamide (CAB in NaOH medium has been investigated at 303K. The reaction rate shows a first order dependence on [CAB]0 , fractional order with respect to [SBL]0 and a negative fractional order with respect to [OH-] . The addition of the reduction product, benzenesulphonamide , retards the reaction rate. The effect of dielectric constant of the medium by varying [MeOH] shows an inverse effect. The addition of chloride ions and variation of ionic strength of the medium have no significant effect on the rate of the reaction. The reaction fails to initiate polymerization of acrylamide. The oxidation products were identified. The Michaelis – Menten type of kinetics has been proposed. The reaction was studied at different temperatures and the values of thermodynamic parameters were computed. A mechanism consistent with the observed kinetics is proposed.

  14. CHARACTERIZING THE EFFECT OF CHLORINE AND CHLORAMINES ON THE FORMATION OF BIOFILM IN A SIMULATED DRINKING WATER DISTRIBUTION SYSTEM

    Science.gov (United States)

    Drinking wate treatment in the US has played a major role in protecting public health through the reduction of wateborne disease. However, carcinogenic and toxic contaminants continue to threaten the quality of surface and ground water in the US. The passage of the Safe Drinking ...

  15. SENSITIVITY OF THREE ENCEPHALITOZOON SPECIES TO CHLORINE AND CHLORAMINE TREATMENT AS DETECTED BY AN IN-VITRO MICROWELL PLATE ASSAY (POSTER PRESENTATION)

    Science.gov (United States)

    Microsporidia are obligate intracellular parasites that form environmentally resistant, infectious spores. These parasites are ubiquitous in the environment, infecting members of almost every class of verebrates and invertebrates. At least 14 microsporidian species that infect th...

  16. Secondary radicals derived from chloramines of apolipoprotein B-100 contribute to HOCl-induced lipid peroxidation of low-density lipoproteins

    DEFF Research Database (Denmark)

    Hazell, L J; Davies, Michael Jonathan; Stocker, R

    1999-01-01

    component to be the major site of attack, whereas others describe extensive lipid peroxidation. The present study addresses this controversy. The results obtained are consistent with the hypothesis that radical-induced oxidation of LDL's lipids by HOCl is a secondary reaction, with most HOCl consumed via...... rapid, non-radical reaction with apolipoprotein B-100. Subsequent incubation of HOCl-treated LDL gives rise to lipid peroxidation and antioxidant consumption in a time-dependent manner. Similarly, with myeloperoxidase/H2O2/Cl- (the source of HOCl in vivo), protein oxidation is rapid and followed...... by an extended period of lipid peroxidation during which further protein oxidation does not occur. The secondary lipid peroxidation process involves EPR-detectable radicals, is attenuated by a radical trap or treatment of HOCl-oxidized LDL with methionine, and occurs less rapidly when the lipoprotein...

  17. Resilience of microbial communities in a simulated drinking water distribution system subjected to disturbances: role of conditionally rare taxa and potential implications for antibiotic-resistant bacteria

    Science.gov (United States)

    Many US water utilities using chloramine as their secondary disinfectant have experienced nitrification episodes that detrimentally impact water quality in their distribution systems. A semi-closed pipe-loop chloraminated drinking water distribution system (DWDS) simulator was u...

  18. Monochloramine Cometabolism by Nitrosomonas europaea under Drinking Water Conditions

    Science.gov (United States)

    Chloramine use is widespread in United States drinking water systems as a secondary disinfectant. While beneficial from the perspective of controlling disinfectant by-product formation, chloramination may promote the growth of nitrifying bacteria because ammonia is present. At ...

  19. 氯胺消毒对铜和不锈钢管壁生物膜的控制作用%Effect of Chloramines Disinfection for Biofilm Formation Control on Copper and Stainless Steel Pipe Materials

    Institute of Scientific and Technical Information of China (English)

    周玲玲; 张永吉; 李星; 李圭白

    2008-01-01

    以松花江为水源的哈尔滨某水厂出厂水为研究对象,采用生物膜培养反应器(rotating annular bioreaetor,RAB)模拟给水管网系统,考察了氯胺对铜和不锈钢2种管材上生物膜的控制情况.结果表明,在无氯胺情况下运行时,铜和不锈钢挂片上的生物膜在第18d和21 d达到最大值,其生物量分别为5.5×103CFU/cm2和2.5×105CFU/cm2,生物膜达到稳定时生物量分别为1.0×3CFU/cm2和1.3×105CFU/cm2,铜挂片上的生物量明显低于不锈钢.反应器在有氯胺状态下运行时,铜和不锈钢挂片上最大生物量为5.0×102CFU/cm2和5.0×104CFU/cm2,分别低于无氯胺情况下1个数量级,达到稳定状态时,其生物量分别为10CFU/cm2以下和3.5×4CFU/cm2,说明氯胺对处于稳定状态的生物膜具有一定的控制作用,对铜挂片上的生物膜具有更明显的控制效果.对消毒剂投量、管材和管肇生物膜HPC进行分析可知,生物膜HPC与余氯胺具有良好的指数相关关系,增加氯胺投量可以降低生物膜HPC数量,氯胺和铜挂片对管壁上的生物膜具有协同灭菌作用.

  20. Hypochlorite-induced oxidation of proteins in plasma

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    1999-01-01

    cases chloramine formation accounts for approx. 20-30% of the added HOCl. These chloramines decompose in a time-dependent manner when incubated at 20 or 37 degrees C but not at 4 degrees C. Ascorbate and urate remove these chloramines in a time- and concentration-dependent manner, with the former being......, the detection of further radical species believed to be intermediates in protein degradation and the loss of the parent protein bands on SDS/PAGE. Fragmentation can be inhibited by methionine and other agents (ascorbate, urate, Trolox C or GSH) capable of removing chloramines and reactive radicals...

  1. LJFO00000000, LJFQ00000000, LJFT00000000, LJFU00000000, LJFX00000000, LJFY00000000

    Data.gov (United States)

    U.S. Environmental Protection Agency — Draft genome sequences of six Mycobacterium immunogenum strains isolated from a chloraminated drinking water distribution system simulator subjected to changes in...

  2. Formation of trichloronitromethane and dichloroacetonitrile in natural waters: Precursor characterization, kinetics and interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Yi-Hsueh; Tung, Hsin-hsin, E-mail: htung@ntu.edu.tw

    2015-02-11

    Graphical abstract: - Highlights: • Aromatic NOM is the important precursor for TCNM and DCAN in chloramination. • TCNM and DCAN originated from DON followed 2nd order reaction kinetics. • TCNM and DCAN formation was faster when precursors were originated from DON than from chloramine. • DCAN formation kinetics equations were confirmed by tyrosine {sup 15}N-chloramination study. • 4-Hydroxybenzaldehyde is an important DCAN precursor during chloramination of natural water. - Abstract: During the chloramination of natural waters, both chloramines and dissolved organic nitrogen (DON) can serve as nitrogen sources for the formation of trichloronitromethane (TCNM) and dichloroacetonitrile (DCAN). The present study investigated the formation kinetics and precursor characteristics of TCNM and DCAN. {sup 15}N-Isotopic monochloramination of the organic fractions produced both {sup 15}N- and {sup 14}N-DCAN and TCNM. Nitrogenous disinfection byproduct (N-DBP) formation, in which the nitrogen precursor originated from DON ({sup 14}N-DCAN and {sup 14}N-TCNM), followed a second-order reaction kinetics (k = 3.2 × 10{sup −5} to 9.4 × 10{sup −5} μM{sup −1} h{sup −1}). The formation of N-DBP where the nitrogen atoms originated from chloramines (e.g. {sup 15}N-DCAN and {sup 15}N-TCNM) correlated linearly with chloramine exposure. The discrepancy in formation kinetics results in that the {sup 14}N-DCAN concentrations were two to ten times higher than {sup 15}N-DCAN in the beginning of the reaction (<12 h). Possible rate equations are proposed in this study. The results of a model compound study support the results of the chloramination of natural waters. In addition, 4-hydroxybenzaldehyde, an oxidative product commonly found during chlorination/chloramination of natural organic matters, gave a 10-fold greater yield of DCAN than that produced from tyrosine; 4-hydroxybenzaldehyde is thus an important precursor in DCAN formation by chloramine incorporation during the

  3. 氯胺T氧化孔雀绿动力学光度法测定食品中痕量碘%Kinetic-Spectrophotometric Determination of Trace Iodine in Food with the Oxidation Reaction of Malachite Green by Chloramine T

    Institute of Scientific and Technical Information of China (English)

    李建国; 乔艳; 魏永前

    1999-01-01

    基于在稀盐酸介质中,碘催化氯胺T氧化孔雀绿而使其褪色的反应,建立了测定痕量碘的新方法.测定碘的线性范围为0~80 μg/L;检出限为1.6μg/L.方法灵敏、简便、选择性好,用于食品中痕量碘的测定,结果满意.

  4. 氯胺消毒对饮用水消毒副产物形成和致突变性的影响%Effect of Chloramine Disinfection on the Formation of Drinking Water Disinfection By-Products and Their Mutagenicity

    Institute of Scientific and Technical Information of China (English)

    衡正昌; 李朝晖; 姜维华; 谢海英

    2003-01-01

    目的评价氯胺消毒对饮用水消毒副产物形成和致突变性的影响.方法分别于2001年8月(丰水期)和2002年3月(枯水期)对成都市某水厂氯胺消毒和液氯消毒饮用水的细菌学指标以及氯仿、四氯化碳含量进行了检测,对其水样的有机浓集物进行了Ames试验,然后比较两种消毒饮用水的消毒副产物含量和致突变性.结果用氯胺消毒的饮用水中余氯量约1 mg/L时均未检出细菌总数和大肠菌群,且氯仿含量较用液氯消毒减少了81%~84%,两种消毒方式的饮水中四氯化碳含量均小于0.2μg/L.对于TA98菌株,液氯消毒的出厂水1.5 L检出阳性反应,而氯胺消毒检出阳性反应的水样量≥6.0 L.结论采用氯胺消毒可以明显降低饮用水氯化副产物的含量和致突变性,其消毒效果不亚于氯化消毒,因此,氯胺是较好的替代消毒剂.

  5. Carbon-Fiber Nitrite Microsensor for In Situ Biofilm Monitoring

    Science.gov (United States)

    During nitrification, nitrite is produced as an intermediate when ammonia is oxidized to nitrate. It is well established that nitrifying biofilm are involved in nitrification episodes in chloraminated drinking water distribution systems with nitrite accumulation occurring during ...

  6. Chemistry, Toxicity and Health Risk Assessment of Drinking Water Disinfection ByProducts

    Science.gov (United States)

    Disinfection byproducts (DBPs) are formed by the reaction of oxidizing chemicals (such as chlorine, ozone and chloramines) used to control waterborne pathogens with natural organic material and other substances in water. DBP mixture composition varies as a function of geographic ...

  7. Formation and Occurrence of Disinfection By-Products

    Science.gov (United States)

    Disinfection by-products (DBPs) are formed when disinfectants such as chlorine, ozone, chlorine dioxide, or chloramines react with naturally occurring organic matter, anthropogenic contaminants, bromide, and iodide during the production of drinking water. There is concern about D...

  8. ALTERNATIVE DISINFECTANTS FOR DRINKING WATER TREATMENT

    Science.gov (United States)

    During a one-year study at Jefferson Parish, Louisiana the chemical, microbiological, and mutagenic effects of using the major drinking water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. ests were performed on samples collected from various treatm...

  9. ALTERNATIVE DISINFECTION FOR DRINKING WATER TREATMENT

    Science.gov (United States)

    During a one-yr study at Jefferson Parish, La., the chemical, microbiological, and mutagenic effects os using the major drinkgin water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. Tests were performed on samples collected from various treatment s...

  10. Draft Genome Sequence of Two Sphingopyxis sp. Strains, Dominant Members of the Bacterial Community Associated with a Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome of two Sphingopyxis spp. strains isolated from a chloraminated drinking water distribution system simulator. Both strains are ubiquitous residents and early colonizers of water distribution systems. Genomic annotation identified a class 1 integron (in...

  11. Nitrification in premise plumbing and its effect on corrosion and water quality degradation

    OpenAIRE

    Zhang, Yan

    2008-01-01

    Nitrification is increasingly of concern in US potable water systems, due to changes from chlorine to chloramine as a secondary disinfectant in order to comply with new regulations for disinfectant by-products. The ammonia that is released from the chloramine decay supports nitrification. A comprehensive literature review systematically examined the complex inter-relationships between nitrification, materials corrosion and metals release. That analysis suggested that nitrification ...

  12. Radio-labeling of polyethylene glycol modification of recombinant human interleukin-6

    International Nuclear Information System (INIS)

    Iodine-125 was used as labeling nuclide, and the PEG-rhIL-6 was labeled by the common used chloramines-T and the two-phase chloramines-T, respectively. The labeled compound was purified by both methods of gel filtration and ultrafiltration respectively. The purity of the labeled PEG-rhIL-6 was determined by both trichloroacetic acid (TCA) and SDS-PAGE, and the biological activity was determined by MTT method. The results demonstrated that the labeling rate and specific radioactivity were 74.5% and 5.513 x 105 Bq/μg for PEG-rhIL-6 by the two-phase chloramines-T method, higher than that by the common used chloramines-T method, which was 62.3% and 4.610 x 105 Bq/μg respectively. The purity of labeled PEG-rhIL-6, purified by both gel filtration and ultrafiltration methods, was over 99% with TCA method. The labeled PEG-rhIL-6 by two-phase chloramines-T method showed two bands, which was identical to that of standard PEG-rhIL-6 though SDS-PAGE, but the labeled PEG-rhIL-6 by common used chloramines-T method had one more band compared with standard PEG-rhIL-6. When determined by MTT, it shown that the biological activity of PEG-rhIL-6 iodinated by common used chloramines-T method was lower than that by two-phase chloramines-T method. (authors)

  13. FATE OF REVERSE OSMOSIS (RO) MEMBRANES DURING OXIDATION BY DISINFECTANTS USED IN WATER TREATMENT: IMPACT ON MEMBRANE STRUCTURE AND PERFORMANCES

    KAUST Repository

    Maugin, Thomas

    2013-12-01

    Providing pretreatment prior RO filtration is essential to avoid biofouling and subsequent loss of membrane performances. Chlorine is known to degrade polymeric membrane, improving or reducing membrane efficiency depending on oxidation conditions. This study aimed to assess the impact of alternative disinfectant, NH2Cl, as well as secondary oxidants formed during chloramination of seawater, e.g. HOBr, HOI, or used in water treatment e.g. ClO2, O3, on membrane structure and performances. Permeability, total and specific rejection (Cl-, SO4 2-, Br-, Boron), FTIR profile, elemental composition were analyzed. Results showed that each oxidant seems to react differently with the membrane. HOCl, HOBr, ClO2 and O3 improved membrane permeability but decreased rejection in different extent. In comparison, chloramines resulted in identical trends but oxidized membrane very slowly. On the contrary, iodine improved membrane rejection e.g. boron, but decreased permeability. Reaction conducted with chlorine, bromine, iodine and chloramines resulted in the incorporation of halogen in the membrane structure. All oxidant except iodine were able to break amide bonds of the membrane structure in our condition. In addition, chloramine seemed to react with membrane differently, involving a potential addition of nitrogen. Chloramination of seawater amplified membrane performances evolutions due to generation of bromochloramine. Moreover, chloramines reacted both with NOM and membrane during oxidation in natural seawater, leading to additional rejection drop.

  14. A picture of polar iodinated disinfection byproducts in drinking water by (UPLC/)ESI-tqMS.

    Science.gov (United States)

    Ding, Guoyu; Zhang, Xiangru

    2009-12-15

    Iodinated disinfection byproducts (DBPs) are generally more toxic than their chlorinated and brominated analogues. Up to date, only a few iodinated DBPs in drinking water have been identified by gas chromatography/mass spectrometry. In this work, a method for fast selective detection of polar iodinated DBPs was developed using an electrospray ionization-triple quadrupole mass spectrometer (ESI-tqMS) by conducting precursor ion scan of iodide at m/z 126.9. With such a method, pictures of polar iodinated DBPs in chlorinated, chloraminated, and chlorine-ammonia treated water samples were achieved. By coupling state-of-the-art ultra performance liquid chromatography (UPLC) to the ESI-tqMS, structures of 17 iodinated DBPs were tentatively proposed. The results fully demonstrate that, with respect to the DBP number/levels among the three disinfection processes, chloramination generally generated the most/highest iodinated DBPs, chlorination generally produced the fewest/lowest iodinated DBPs, and chlorine-ammonia sequential treatment formed iodinated DBPs lying in between; the numbers of iodinated DBPs in chloraminated Suwannee River Fulvic Acid (SRFA) and Humic Acid (SRHA) were nearly the same, but the levels of aliphatic iodinated DBPs were higher in the chloraminated SRFA while the levels of aromatic iodinated DBPs were higher in the chloraminated SRHA; a couple of nitrogenous iodinated DBPs were found in chloramination and chlorine-ammonia treatment. The ratio of total organic iodine levels in chlorine-ammonia sequential treatment and chloramination could be expressed as a function of the lag time of ammonia addition.

  15. Effect of pipe material and low level disinfectants on biofilm development in a simulated drinking water distribution system

    Institute of Scientific and Technical Information of China (English)

    Ling-ling ZHOU; Yong-ji ZHANG; Gui-bai LI

    2009-01-01

    The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique.The experiments were carried out with four annular reactors(ARs)with stainless steel(SS)or copper(Cu)material slides.The results showed that there were fewer bacteria attached to Cu slides without a disinfectant compared with those attached to SS slides.When the water was disinfected with chloramines,the heterotrophic plate counts(HPCs)on the biofilm attached to the Cu slides were significantly lower(by 3.46 log CFU/cm2)than those attached to the SS slides.Likewise,the biofilm HPC numbers on the Cu slides were slightly lower(by 1.19log CFU/cm2) than those on the SS slides disinfected with chlorine.In a quasi-steady state.the HPC levels on Cu slides can be reduced to 3.0 log CFU/cm2 with chlorine and to about 0.9 log CFU/cm2 with chloramines.The addition of chloramines resulted in a more efficient reduction of biofilm heterotrophic bacteria than did chlorine.We concluded that the chlorine and chloramines levels usually employed in water distribution system were not SUfficient to prevent the growth and development of microbial biofilm.The combination of copper pipe slides and chlorarnincs as the disinfectant was the most efficient combination to bring about diminished bacterial levels.

  16. Redox gradients in distribution systems influence water quality, corrosion, and microbial ecology.

    Science.gov (United States)

    Masters, Sheldon; Wang, Hong; Pruden, Amy; Edwards, Marc A

    2015-01-01

    Simulated distribution systems (SDSs) defined the interplay between disinfectant type (free chlorine and chloramines), water age (1-10.2 days), and pipe material (PVC, iron and cement surfaces) on water chemistry, redox zones and infrastructure degradation. Redox gradients developed as a function of water age and pipe material affected the quality of water consumers would receive. Free chlorine was most stable in the presence of PVC while chloramine was most stable in the presence of cement. At a 3.6 day water age the residual in the chlorinated PVC SDS was more than 3.5 times higher than in the chlorinated iron or cement systems. In contrast, the residual in the chloraminated cement SDS was more than 10 times greater than in the chloraminated iron or PVC systems. Near the point of entry to the SDSs where disinfectant residuals were present, free chlorine tended to cause as much as 4 times more iron corrosion when compared to chloramines. Facultative denitrifying bacteria were ubiquitous, and caused complete loss of nitrogen at distal points in systems with iron, and these bacteria co-occurred with very severe pitting attack (1.6-1.9 mm/year) at high water age. PMID:25462724

  17. Reactivity of selenium-containing compounds with myeloperoxidase-derived chlorinating oxidants

    DEFF Research Database (Denmark)

    Carroll, Luke; Pattison, David I.; Fu, Shanlin;

    2015-01-01

    and N-chloramines, causes damage to host tissue. Low molecular mass thiol compounds, including glutathione (GSH) and methionine (Met), have demonstrated efficacy in scavenging MPO-derived oxidants, which prevents oxidative damage in vitro and ex vivo. Selenium species typically have greater reactivity...... toward oxidants compared to the analogous sulfur compounds, and are known to be efficient scavengers of HOCl and other hypohalous acids produced by MPO. In this study, we examined the efficacy of a number of sulfur and selenium compounds to scavenge a range of biologically relevant N-chloramines and...... oxidants produced by both isolated MPO and activated neutrophils and characterized the resulting selenium-derived oxidation products in each case. A dose-dependent decrease in the concentration of each N-chloramine was observed on addition of the sulfur compounds (cysteine, methionine) and selenium...

  18. Biological stability in drinking water: a regression analysis of influencing factors

    Institute of Scientific and Technical Information of China (English)

    LU Wei; ZHANG Xiao-jian

    2005-01-01

    Some parameters, such as assimilable organic carbon(AOC), chloramine residual, water temperature, and water residence time, were measured in drinking water from distribution systems in a northern city of China. The measurement results illustrate that when chloramine residual is more than 0.3 mg/L or AOC content is below 50 tμg/L, the biological stability of drinking water can be controlled.Both chloramine residual and AOC have a good relationship with Heterotrophic Plate Counts(HPC)(log value), the correlation coefficient was -0.64 and 0.33, respectively. By regression analysis of the survey data, a statistical equation is presented and it is concluded that disinfectant residual exerts the strongest influence on bacterial growth and AOC is a suitable index to assess the biological stability in the drinking water.

  19. Effect of pre-ozonation on the formation and speciation of DBPs.

    Science.gov (United States)

    Hua, Guanghui; Reckhow, David A

    2013-09-01

    The objective of this study was to quantitatively evaluate the effect of pre-ozonation on the formation and speciation of disinfection byproducts (DBPs) from subsequent chlorination and chloramination. Laboratory experiments were conducted on six diverse natural waters with low to medium bromide concentrations. Four groups of DBPs were investigated in this study: trihalomethanes (THMs), trihaloacetic acids (THAAs), dihaloacetic acids (DHAAs), and dihaloacetonitriles (DHANs). The results showed that the relative destructions of chlorination DBP precursors by ozone generally follow the order of DHANs > THMs & THAAs > DHAAs. Pre-ozonation substantially increased the DHAA precursors in the waters with low specific ultraviolet absorbance values. Pre-ozonation shifted the formation of DBPs to more brominated species. The bromine substitution factors (BSF) of different chlorination DBPs typically increased by 1-8 percentage points after ozonation. Pre-ozonation reduced the yields of chloramination DHAAs and THMs and increased the BSFs of chloramination DHAAs by 1-6 percentage points.

  20. Impact of disinfection on drinking water biofilm bacterial community.

    Science.gov (United States)

    Mi, Zilong; Dai, Yu; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-11-01

    Disinfectants are commonly applied to control the growth of microorganisms in drinking water distribution systems. However, the effect of disinfection on drinking water microbial community remains poorly understood. The present study investigated the impacts of different disinfectants (chlorine and chloramine) and dosages on biofilm bacterial community in bench-scale pipe section reactors. Illumina MiSeq sequencing illustrated that disinfection strategy could affect both bacterial diversity and community structure of drinking water biofilm. Proteobacteria tended to predominate in chloraminated drinking water biofilms, while Firmicutes in chlorinated and unchlorinated biofilms. The major proteobacterial groups were influenced by both disinfectant type and dosage. In addition, chloramination had a more profound impact on bacterial community than chlorination.

  1. Hypochlorite-induced damage to DNA, RNA, and polynucleotides

    DEFF Research Database (Denmark)

    Hawkins, Clare L; Davies, Michael Jonathan

    2002-01-01

    HOCl damage to DNA, RNA, and polynucleotides. Reaction of HOCl with these materials is shown to yield multiple semistable chloramines (RNHCl/RR'NCl), which are the major initial products, and account for 50-95% of the added HOCl. These chloramines decay by thermal and metal-ion catalyzed processes......, to give nucleoside-derived, nitrogen-centered, radicals. The latter have been characterized by EPR spin trapping. The propensity for radical formation with polynucleotides is cytidine > adenosine = guanosine > uridine = thymidine. The rates of decay, and yield of radicals formed, are dependent...

  2. Biostability in distribution systems in one city in southern China: characteristics, modeling and control strategy.

    Science.gov (United States)

    Lu, Pinpin; Zhang, Xiaojian; Zhang, Chiqian; Niu, Zhangbin; Xie, Shuguang; Chen, Chao

    2014-02-01

    This study investigated the bacterial regrowth in drinking water distribution systems receiving finished water from an advanced drinking water treatment plant in one city in southern China. Thirteen nodes in two water supply zones with different aged pipelines were selected to monitor water temperature, dissolved oxygen (DO), chloramine residual, assimilable organic carbon (AOC), and heterotrophic plate counts (HPC). Regression and principal component analyses indicated that HPC had a strong correlation with chloramine residual. Based on Chick-Watson's Law and the Monod equation, biostability curves under different conditions were developed to achieve the goal of HPC systems. This work could provide some new insights towards biostability control in real distribution systems.

  3. Preparation and characterization of 125 I labeled bovine serum albumin

    Directory of Open Access Journals (Sweden)

    K S Ashwitha Rai

    2015-01-01

    Full Text Available Bovine serum albumin is a model protein, which has been conventionally used as protein standard and in many areas of biochemistry, pharmacology and medicine. Radioiodination procedure for bovine serum albumin employing chloramine-T as an oxidant with slight modification was evaluated critically to establish the optimal conditions for the preparation of radiolabeled tracer ( 125 I-BSA with required specific activity without impairing the immune reactivity and biological activity. Optimized radioiodination procedure involving 10 µg of chloramine-T along with 20 µg of sodium metabisulphite with 60 seconds incubation at 2° yielded 125 I-BSA with high integrity.

  4. Fragmentation of extracellular matrix by hypochlorous acid

    DEFF Research Database (Denmark)

    Woods, Alan A; Davies, Michael Jonathan

    2003-01-01

    of the MPO-derived oxidant hypochlorous acid (HOCl) with extracellular matrix from vascular smooth muscle cells and healthy pig arteries has been examined. HOCl is rapidly consumed by such matrix samples, with the formation of matrix-derived chloramines or chloramides. The yield of these intermediates...... increases with HOCl dose. These materials undergo a time- and temperature-dependent decay, which parallels the release of sugar and protein components from the treated matrix, consistent with these species being important intermediates. Matrix damage is enhanced by species that increase chloramine...

  5. Superoxide radicals can act synergistically with hypochlorite to induce damage to proteins

    DEFF Research Database (Denmark)

    Hawkins, Clare L; Rees, Martin D; Davies, Michael Jonathan

    2002-01-01

    Activated phagocytes generate both superoxide radicals via a respiratory burst, and HOCl via the concurrent release of the haem enzyme myeloperoxidase. Amine and amide functions on proteins and carbohydrates are major targets for HOCl, generating chloramines (RNHCl) and chloramides (RC(O)NClR'), ...

  6. Using prechloramination to control trihalomethanes formation in River Huang water with high bromide

    Institute of Scientific and Technical Information of China (English)

    TAO Hui; CHEN Wei; LIN Tao; LIU Cheng; CHEN Jie; LI Gui-bai

    2008-01-01

    An effective technology in controlling trihalomethanes (THMs)formation in the case of large amounts of bromide presenting wag proposed,and the water of River Huang seriously polluted by bromide in winter in Tianjin City wag studied.The THMs formation characteristics during prechloramination using preformed chloramines and convened chloramines were studied through jar tests.Results show that,in prechloramination process,the formation of THMs by preformed chloramines is very few,while that by converted chloramines is a little higher.And the formation of THMs,especially Br-substituted THMs,increases with tIle increase of time and Cl2:N ratio as well as the decrease of pH.The result obtained in a pilot plant shows that compared with preehlorination,the prechlommination process can efficiendy control the formation of THMs,especially the Br-substituted species.With equal chlorine dosage.the prechloramination can maintain a hrser chlorine residue which offers a larger CT value than prechlorination.

  7. One-pot synthesis of new series 3,4,5-trisubstituted-dihydroisoxazoline derivatives via 1,3-dipolar cycloaddition of nitrile oxides with chalcones

    Indian Academy of Sciences (India)

    Raad Kasim Yhya; K M Lokanatha Rai; Ebraheem Abdu Musad

    2013-07-01

    We have synthesized a series of novel isoxazolines via 1,3-dipolar cycloaddition reaction. Aromatic aldoximes undergo oxidative-dehydrogenation with chloramine-T to give nitrile oxides, which were reacted with chalcones to afford of 3,4,5-trisubstituted 4,5-dihydroisoxazolines in a good yield.

  8. Microelectrode investigation of the reactions between metallic pipe materials and monochloramine

    Science.gov (United States)

    Water quality parameters (i.e., pH, dissolved oxygen [DO], and phosphate) are known to impact metal reactivity with disinfectants and therefore corrosion and metals release into drinking water supplies. With various water utilities switching from free chlorine to chloramines for ...

  9. IODO-ACID DISINFECTION BY-PRODUCTS IN DRINKING WATER: DOES LC/ESI-MS/MS OFFER AN ADVANTAGE OVER GC/NCI-MS?

    Science.gov (United States)

    As part of a recent Nationwide Disinfection By-Product (DBP) Occurrence Study, iodo-acids were identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid, bromoiodoacetic acid, (E)-3-bromo-3-iodo-prope...

  10. OCCURRENCE OF IODO-ACID AND IODO-THM DISINFECTION BY-PRODUCTS IN DRINKING WATER

    Science.gov (United States)

    As part of a recent Nationwide Disinfection By-product (DBP) Occurrence Study, iodo-acids were identified for the first time as DBPs in drinking water disinfected with chloramines. The iodo-acids identified included iodoacetic acid, bromoiodoacetic acid, (E)-3-bromo-3-iodo- prope...

  11. Improved radioimmunotherapy of hematologic malignancies. Progress report, November 1, 1993--October 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Press, O.W.

    1994-08-04

    This report summaries progress made during the time interval between November 1, 1993 and October 31, 1994 and briefly describes studies on the metabolism of antibodies targeting B cell antigens, retention of labeled antibodies by human B cell lymphocytes, and tissue distribution of Chloramine T and tyramine cellobiose labeled antibodies in mice harboring a human erythroleukemia tumor transplant.

  12. Comparison and evaluation of different methods for α-MSH labelling

    International Nuclear Information System (INIS)

    The authors have studied the behaviour of 125I-labelled α-MSH under different experimental conditions. Until now, the chloramine T method had been used by most investigators with variable results. They have tested three other labelling techniques based on 125I mild oxidation: (1) an enzymatic method with lactoperoxidase, (2) a sparingly soluble chloramine method (T.D.G.U.), and (3) modified chloramine T procedure, 'the iodine volatilization method'. Labelled hormone obtained after each kind of iodination was assayed for immunoreactivity. In addition, time course degradation was measured by classical RIA incubation procedures. Charcoal-dextran was used to separate bound and free antigen. The authors have found chloramine T-iodinated α-MSH to be significantly more damaged than preparations obtained by other methods and to be less stable when stored at -180C. No differences were found between the differently labelled 125I-labelled α-MSH fresh preparations in binding to surface receptors of human melanoma cell lines in culture. (Auth.)

  13. Synthesis of new series of 4, 5-dihydroisoxazole-5-carboxylate derivatives for the study of their liquid crystalline properties

    Indian Academy of Sciences (India)

    SUMANA Y KOTIAN; NARAYANA U KUDVA N; K M LOKANATHA RAI; K BYRAPPA

    2016-07-01

    A new series of 4,5-dihydroisoxazole-5-carboxylate derivatives were synthesized via [3+2] cycloaddition reaction between ethyl acrylate and nitrile oxide generated in situ in presence of Chloramine-T. The synthesized derivatives were characterized by Mass, IR and NMR Spectroscopy and their mesomorphic behavior were studied using DSC and Polarising Optical Microscopy.

  14. TRIBROMOPYRROLE, BROMINATED ACIDS, AND OTHER DISINFECTION BYPRODUCTS PRODUCED BY DISINFECTION OF DRINKING WATER RICH IN BROMIDE

    Science.gov (United States)

    Using gas chromatography/mass spectrometry (GC/MS), we investigated the formation of disinfection byproducts (DBPs) from high bromide waters (2 mg/L) treated with chlorine or chlorine dioxide used in combination with chlorine and chloramines. This study represents the first comp...

  15. 40 CFR 141.133 - Compliance requirements.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Disinfectant Residuals, Disinfection Byproducts, and Disinfection Byproduct Precursors § 141.133 Compliance requirements. (a) General requirements. (1) Where... chlorine or chloramine, the system is out of compliance at the end of that quarter. (b)...

  16. Genotoxicity of Disinfection By-products: Comparison to Carcinogenicity

    Science.gov (United States)

    Disinfection by-products (DBPs) can be formed when water is disinfected by various agents such as chlorine, ozone, or chloramines. Among the >600 DBPs identified in drinking water, 11 are regulated by the U.S. Environmental Protection Agency, and another ~70 DBPs that occur at s...

  17. 40 CFR 141.2 - Definitions.

    Science.gov (United States)

    2010-07-01

    ..., chloramines, and ozone added to water in any part of the treatment or distribution process, that is intended... equivalent demonstration. Disinfection means a process which inactivates pathogenic organisms in water by... disinfection, addition of corrosion control chemicals). First draw sample means a one-liter sample of tap...

  18. OVERVIEW: DISINFECTION OF HELICOBACTER PYLORI AND AEROMONAS SPECIES

    Science.gov (United States)

    Helicobacter pylori and Aeromonas hydrophila are contaminants listed on the USEPA's 1998 Contaminant Candidate List (CCL).The sensitivity of H. pylori to chlorine and of Aeromonas spp. to inactivation by free chlorine, chloramine and ultraviolet (UV) was examined. Selective and...

  19. 40 CFR 141.624 - Additional requirements for consecutive systems.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Stage 2 Disinfection... system that does not add a disinfectant but delivers water that has been treated with a primary or... requirements for chlorine and chloramines in § 141.131 (c) and § 141.132(c)(1) and the compliance...

  20. Whole-Genome Sequences of Four Strains Closely Related to Members of the Mycobacterium chelonae Group, Isolated from Biofilms in a Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome sequences of four Mycobacterium chelonae group strains from biofilms obtained after a ‘chlorine burn’ in a chloraminated drinking water distribution system simulator. These opportunistic pathogens have been detected in drinking and hospital water distr...

  1. Synthesis and radioiodination of analogues of substance P for the building up of a radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Bienert, M.; Schmidt, H.E.; Ehrlich, A.; Forner, K.; Klauschenz, E.; Furkert, J.; Rathsack, R.; Niedrich, H. (Akademie der Wissenschaften der DDR, Berlin. Inst. fuer Wirkstofforschung; Akademie der Wissenschaften der DDR, Berlin-Buch. Zentralinstitut fuer Isotopen- und Strahlenforschung)

    1984-02-01

    The substance P (SP) analogs (Lys(MSOC)/sup 3/)-SP, (Tyr/sup 8/)-SP, (Tyr/sup 8/,Nle/sup 11/)-SP and (p-HPA/sup 1/)-SP have been synthesized by classical methods of peptide synthesis as well as by the liquid phase peptide synthesis (LPPS) to allow conjugation with protein in the N..cap alpha..-position and radioiodination. (Tyr/sup 8/)-SP and (p-HPA-Arg/sup 1/)-SP have been radioiodinated by the chloramine T- and the lactoperoxidase method. A complete S-oxidation of SP was observed, when the chloramine T procedure was used, but this modification does not disturb the assay. The introduction of the (/sup 125/I-pHPA-Arg/sup 1/)-SP-tracer led to considerable improvements of our SP-radioimmunoassay.

  2. Labelling of human serum albumin with iodine-131 for diagnosis in nuclear medicine

    International Nuclear Information System (INIS)

    Labelling of 131I-human serum albumin with I-131 from a solution of 131I-sodium iodide using chloramine T as an oxidant agent is studied. Parameters which can influence on the labelling yield like mass of human serum albumin, and chloramine T, pH of the reaction, reaction time and activity of 131I are also studied. The purification of the labeled product by means of IRA-410 Amberlite ion-exchange resin in chloride form and the sterilization of the 131I-human serum albumin by its passage through a 0,22μ millipore filter are carried out. The radiochemistry control of the final product by paper chromatography and the microbiological control by cultivation of microorganisms in fluid medium: nutrient broth, sodium thioglycollate broth and Sabouraud, are performed. The stability of the radiopharmaceutical until ten days after its preparation is analysed by means of radiochemical control. (Author)

  3. [Sensitivity of Ps. aeruginosa to disinfectant agents].

    Science.gov (United States)

    Korudzhiĭski, N; Tsankova, S; Karadzhov, S

    1986-01-01

    Pseudomonas aeruginosa strains, isolated from semen of bulls as well as from the surrounding milieu at Artificial Insemination Stations, were tested for susceptibility to disinfection agents, such as fesiasept, concentrate C4, and chloramine with 25% active chlorine and sodium hydroxide. The investigation was carried out in vitro under practical conditions too. The analysis of results led to the conclusion that in the case of environmental contamination with Ps. aeruginosa along with semen contamination most effective proved concentrate C4 in the form of 2.5 per cent water solution. The disinfection of lab glassware and equipment, instruments, towels, kerchiefs, cloths, and white overalls and aprons is to be carried out with 1.5 per cent water solution of chloramine. PMID:3101277

  4. Kinetics and Mechanism of Electron Transfer Reaction: Oxidation of Sulfanilic Acid by N-Chloro-p-Toluene Sulfonamide in Acid Perchlorate Medium

    Energy Technology Data Exchange (ETDEWEB)

    Sailani, Riya; Bhasin, Meneka; Khandelwal, C. L.; Sharma, P. D. [Univ. of Rajasthan, Jaipur (India)

    2014-01-15

    The kinetics and mechanism of oxidation of sulfanilic acid by N-chloro-p-toluene sulfonamide (chloramine-T) have been studied in acid medium. The species of chloramine-T were analysed on the basis of experimental observations and predominantly reactive species was taken into account for proposition of most plausible reaction mechanism. The derived rate law (1) conforms to such a mechanism. All kinetic parameters were evaluated. Activation parameters such as energy and entropy of activation were calculated to be (61.67 ± 0.47) kJ mol{sup -1} and (-62.71 ± 2.48) JK{sup -1}mol{sup -1} respectively employing Eyring equation.

  5. The effect of chemical anti-inhibitors on fibrinolytic enzymes and inhibitors

    DEFF Research Database (Denmark)

    Sidelmann, Johannes Jakobsen; Jespersen, J; Kluft, C;

    1997-01-01

    proteases. We studied the influence of chemical anti-inhibitors (chloramine T, flufenamate, sodium lauryl sulfate, and methylamine) on fibrinolytic serine proteases and fibrinolytic enzyme inhibitors using the physiological substrate fibrin as plasmin substrate. Low concentrations of chloramine T (0.01 mmol....../l) prevent the inhibition of plasminogen activators. Higher concentrations (1 mmol/l) reduce the inhibition of plasmin, but simultaneously quench the plasminogen activator activity. Flufenamate eliminates most fibrinolytic enzyme inhibitors, but increases the activity of plasmin (apparent recovery 140......Fibrinolytic enzyme inhibitors hamper the determination of the specific fibrinolytic serine protease activity. Reportedly, chemical anti-inhibitors eliminate the influence of fibrinolytic inhibitors, but it remains unclear to what extent they change the specific activity of fibrinolytic serine...

  6. Preparation and Evaluation of (125I) Daunorubicin as a Potential Agent for Tumor Detection and radiotherapy

    International Nuclear Information System (INIS)

    In this study, the optimization of daunorubicin labeling with iodine-125 and its biological evaluation were described. Daunorubicin was labeled via direct electrophilic substitution using chloramine-T as oxidizing agent. The optimum amounts of reactants were: 40μg daunorubicin, 30μg Chloramine-T and ∼ 19 KBq carrier free Na125I. The labeled daunorubicin was stable for more than 24 hours. Results of the in-vivo evaluation revealed that the tracer, [125I] daunorubicin, tends to localize in tissues with high proliferation rate with preferential accumulation in cancerous tissues. Imaging should be carried at 3 hours post injection. The in-vitro cell growth inhibition assay showed that the effect of [125I] Daunorubicin was stronger than the effect of cold daunorubicin which strongly suggested that its cytotoxicity was mainly due to radiotoxicity rather than chemotherapeutic activity.

  7. Occurrence of by-products of strong oxidants reacting with drinking water contaminants--scope of the problem.

    OpenAIRE

    Rice, R G; Gomez-Taylor, M

    1986-01-01

    This paper describes results of a detailed literature review of the organic and inorganic by-products that have been identified as being formed in aqueous solution with four of the strong oxidizing/disinfecting agents commonly employed in drinking water treatment. These agents are: chlorine, chlorine dioxide, chloramine, and ozone. Significant findings include the production of similar nonchlorinated organic oxidation products from chlorine, chlorine dioxide, and ozone. In addition, all three...

  8. Human growth hormone (HGH), ch. 6

    International Nuclear Information System (INIS)

    A radioimmunoassay method for the human growth hormone (HGH) is described. The requirements are discussed in detail and a scheme for the preparation of incubation mixtures is given. HGH is labelled with 125I by the chloramine T method and purified by gel filtration or electrophoresis. Separation of bound and free-labelled hormones is performed by absorption of the free hormone, using talc or charcoal

  9. Relative importance of N-nitrosodimethylamine compared to total N-nitrosamines in drinking waters.

    Science.gov (United States)

    Dai, Ning; Mitch, William A

    2013-04-16

    A U.S.-wide occurrence survey conducted as part of the Unregulated Contaminant Monitoring Rule 2 found that N-nitrosodimethylamine (NDMA) was present in 34% of chloraminated drinking water samples but was the most prevalent of the six N-nitrosamines evaluated using U.S. Environmental Protection Agency (EPA) Method 521. If the U.S. EPA considers limiting exposures to N-nitrosamines as a group, a critical question is whether NDMA is the most prevalent N-nitrosamine or whether significant concentrations occur for N-nitrosamines other than those captured by EPA Method 521. A total N-nitrosamine assay was developed and applied to 36 drinking water plant effluents or distribution system samples from 11 utilities, including 9 utilities that practiced chloramination for secondary disinfection. Concurrent application of EPA Method 521 indicated that NDMA was the most prevalent of the Method 521 N-nitrosamines yet accounted for ∼5% of the total N-nitrosamine pool on a median basis. Among eight plant influent waters, NDMA was detected once, while total N-nitrosamines were detected in five samples, suggesting the importance of source water protection. Similar to NDMA, total N-nitrosamine concentrations in source waters increased after chloramination. Chloramines were applied to organic precursors serving as models for pristine natural organic matter, algal exudate, wastewater effluent, and polyDADMAC quaternary amine-based coagulation polymers. While high yields of NDMA were restricted to the wastewater effluent and polyDADMAC, high yields of total N-nitrosamines were observed from the algal exudate, the wastewater effluent, and polyDADMAC. The results suggest that N-nitrosamines as a class may be more prevalent than suggested by occurrence surveys conducted using EPA Method 521.

  10. [Some properties of plasmocoagulase of the causative agents of glanders and melioidosis].

    Science.gov (United States)

    Narbutovich, N I; Lomova, L V; Ageeva, N P; Kucheriaeva, V T; Seimova, I K

    2005-01-01

    Criteria for the evaluation of the plasmocoagulase activity of natural isolates and mutant strains of the causative agents of glanders and melioidosis were worked out, which made it possible to subdivide them by this sign into pathogens with high, moderate and low activity. Plasmocoagulase produced by pathogenic Burkholderia was shown to be a thermolabile enzyme, comparatively stable with respect to the action of such chemico-biological agents as hydrogen peroxide and chloramine.

  11. Chlorination of Taurine by Human Neutrophils: EVIDENCE FOR HYPOCHLOROUS ACID GENERATION

    OpenAIRE

    Weiss, Stephen J; Klein, Roger; Slivka, Adam; Wei, Maria

    1982-01-01

    The model hydrogen peroxide-myeloperoxidase-chloride system is capable of generating the powerful oxidant hypochlorous acid, which can be quantitated by trapping the generated species with the β-amino acid, taurine. The resultant stable product, taurine chloramine, can be quantitated by its ability to oxidize the sulfhydryl compound, 5-thio-2-nitro-benzoic acid to the disulfide, 5,5′-dithiobis(2-nitroben-zoic acid) or to oxidize iodide to iodine. Using this system, purified myeloperoxidase in...

  12. New aquaculture drugs under FDA review

    Science.gov (United States)

    Bowker, James D.; Gaikowski, Mark P.

    2012-01-01

    Only eight active pharmaceutical ingredients available in 18 drug products have been approved by the U.S. Food and Drug Administration for use in aquaculture. The approval process can be lengthy and expensive, but several new drugs and label claims are under review. Progress has been made on approvals for Halamid (chloramine-T), Aquaflor (florfenicol) and 35% PeroxAid (hydrogen peroxide) as therapeutic drugs. Data are also being generated for AQUI-S 20E, a fish sedative.

  13. Exhaled nitric oxide and airway hyperresponsiveness in workers: a preliminary study in lifeguards

    OpenAIRE

    Massin Nicole; Bohadana Abraham; Demange Valérie; Wild Pascal

    2009-01-01

    Abstract Background Airway inflammation and airway hyperresponsiveness (AHR) are two characteristic features of asthma. Fractional exhaled nitric oxide (FENO) has shown good correlation with AHR in asthmatics. Less information is available about FENO as a marker of inflammation from work exposures. We thus examined the relation between FENO and AHR in lifeguards undergoing exposure to chloramines in indoor pools. Methods 39 lifeguards at six indoor pools were given a respiratory health questi...

  14. Ethyl 4,4''-Difluoro-5'-hydroxy-1,1':3',1''-terphenyl-4'-carboxylate

    Directory of Open Access Journals (Sweden)

    Badiadka Narayana

    2011-11-01

    Full Text Available A simple and novel route for the synthesis of new terphenyl derivative as well as oxidative aromatization of α,β-unsaturated cyclohexenone to the corresponding phenol derivative is developed. The present work involves the condensation of ethylacetoacetate with 4,4'-difluoro chalcone followed by the aromatization using chloramine-T in acetic acid to yield the title compound (3. The synthesized compound (3 is well characterized by IR, NMR, LCMS and elemental analysis.

  15. Ethyl 4,4''-Difluoro-5'-hydroxy-1,1':3',1''-terphenyl-4'-carboxylate

    OpenAIRE

    Badiadka Narayana; Balladka Kunhanna Sarojini; Seranthimata Samshuddin

    2011-01-01

    A simple and novel route for the synthesis of new terphenyl derivative as well as oxidative aromatization of α,β-unsaturated cyclohexenone to the corresponding phenol derivative is developed. The present work involves the condensation of ethylacetoacetate with 4,4'-difluoro chalcone followed by the aromatization using chloramine-T in acetic acid to yield the title compound (3). The synthesized compound (3) is well characterized by IR, NMR, LCMS and elemental analysis.

  16. Combined toxicity effects of chlorine, ammonia, and temperature on marine plankton. Progress report, February 1, 1975--September 15, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J. H.; Goldman, J. C.

    1975-10-01

    Research on the combined effects of chlorine, ammonia, and temperature on marine plankton have been carried out for 7/sup 1///sub 2/ months. Continuous-flow bioassay units have been constructed for larval species, juvenile fish, and phytoplankton. A detailed study on lobster (Homarus americanus) larvae and other studies on killifish (Fundulus heteroclitus) larvae and juveniles, and juvenile scup (Stenotomus versicolor) and winter flounder (Pseudopleuronectes americanus) have been performed. Results to date indicate that there is an apparent and, as yet undetermined, chlorine demand of seawater; there is a differential toxic effect of chlorine and chloramines--lobsters were more sensitive to chloramines, whereas the fish species were more affected by free chlorine; respiration results indicate that significant stress occurs at toxicant levels below the onset of mortality, thus raising questions regarding the applicability of standard bioassay data; temperature elevation exerts a strong synergistic effect on chlorine-chloramine toxicity; and effects of exposure to halogen toxicity appear irreversible as revealed by persistent reductions in metabolic activity. It appears that chlorine toxicity to marine biota can occur even though chlorine residuals cannot be detected by current analytical techniques. These results support the findings of others that chlorine toxicity is a serious environmental pollutant. (auth)

  17. Impact of Nitrification on the Formation of N-Nitrosamines and Halogenated Disinfection Byproducts within Distribution System Storage Facilities.

    Science.gov (United States)

    Zeng, Teng; Mitch, William A

    2016-03-15

    Distribution system storage facilities are a critical, yet often overlooked, component of the urban water infrastructure. This study showed elevated concentrations of N-nitrosodimethylamine (NDMA), total N-nitrosamines (TONO), regulated trihalomethanes (THMs) and haloacetic acids (HAAs), 1,1-dichloropropanone (1,1-DCP), trichloroacetaldehyde (TCAL), haloacetonitriles (HANs), and haloacetamides (HAMs) in waters with ongoing nitrification as compared to non-nitrifying waters in storage facilities within five different chloraminated drinking water distribution systems. The concentrations of NDMA, TONO, HANs, and HAMs in the nitrifying waters further increased upon application of simulated distribution system chloramination. The addition of a nitrifying biofilm sample collected from a nitrifying facility to its non-nitrifying influent water led to increases in N-nitrosamine and halogenated DBP formation, suggesting the release of precursors from nitrifying biofilms. Periodic treatment of two nitrifying facilities with breakpoint chlorination (BPC) temporarily suppressed nitrification and reduced precursor levels for N-nitrosamines, HANs, and HAMs, as reflected by lower concentrations of these DBPs measured after re-establishment of a chloramine residual within the facilities than prior to the BPC treatment. However, BPC promoted the formation of halogenated DBPs while a free chlorine residual was maintained. Strategies that minimize application of free chlorine while preventing nitrification are needed to control DBP precursor release in storage facilities.

  18. Detection of Legionella, L. pneumophila and Mycobacterium Avium Complex (MAC along Potable Water Distribution Pipelines

    Directory of Open Access Journals (Sweden)

    Harriet Whiley

    2014-07-01

    Full Text Available Inhalation of potable water presents a potential route of exposure to opportunistic pathogens and hence warrants significant public health concern. This study used qPCR to detect opportunistic pathogens Legionella spp., L. pneumophila and MAC at multiple points along two potable water distribution pipelines. One used chlorine disinfection and the other chloramine disinfection. Samples were collected four times over the year to provide seasonal variation and the chlorine or chloramine residual was measured during collection. Legionella spp., L. pneumophila and MAC were detected in both distribution systems throughout the year and were all detected at a maximum concentration of 103 copies/mL in the chlorine disinfected system and 106, 103 and 104 copies/mL respectively in the chloramine disinfected system. The concentrations of these opportunistic pathogens were primarily controlled throughout the distribution network through the maintenance of disinfection residuals. At a dead-end and when the disinfection residual was not maintained significant (p < 0.05 increases in concentration were observed when compared to the concentration measured closest to the processing plant in the same pipeline and sampling period. Total coliforms were not present in any water sample collected. This study demonstrates the ability of Legionella spp., L. pneumophila and MAC to survive the potable water disinfection process and highlights the need for greater measures to control these organisms along the distribution pipeline and at point of use.

  19. Occurrence and formation of chloro- and bromo-benzoquinones during drinking water disinfection.

    Science.gov (United States)

    Zhao, Yuli; Anichina, Janna; Lu, Xiufen; Bull, Richard J; Krasner, Stuart W; Hrudey, Steve E; Li, Xing-Fang

    2012-09-15

    Consumption of chlorinated drinking water has shown somewhat consistent association with increased risk of bladder cancer in a series of epidemiological studies, but plausible causative agents have not been identified. Halobenzoquinones (HBQs) have been recently predicted as putative disinfection byproducts (DBPs) that might be of toxicological relevance. This study reports the occurrence frequencies and concentrations of HBQs in plant effluents from nine drinking water treatment plants in the USA and Canada, where four common disinfection methods, chlorination, chloramination, chlorination with chloramination, and ozonation with chloramination, are used. In total, 16 water samples were collected and analyzed for eight HBQs: 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ), 2,6-dibromo-1,4-benzoquinone (2,6-DBBQ), 2,6-dichloro-3-methyl-1,4-benzoquinone (2,6-DC-3-MBQ), 2,3,6-trichloro-1,4-benzoquinone (2,3,6-TriCBQ), 2,5-dibromo-1,4-benzoquinone (2,5-DBBQ), 2,3-dibromo-5,6-dimethyl-1,4-benzoquinone (2,3-DB-5,6-DM-BQ), tetrabromo-1,4-benzoquinone (TetraB-1,4-BQ), and tetrabromo-1,2-benzoquinone (TetraB-1,2-BQ). Of these, 2,6-DCBQ, 2,6-DBBQ, 2,6-DC-3-MBQ and 2,3,6-TriCBQ were detected in 16, 11, 6, and 3 of the 16 samples with the method detection limit (DL) of 1.0, 0.5, 0.9 and 1.5 ng/L, respectively, using a solid phase extraction and high performance liquid chromatography-tandem mass spectrometry method. The concentrations were in the ranges of 4.5-274.5 ng/L for 2,6-DCBQ, below DL to 37.9 ng/L for 2,6-DBBQ, below DL to 6.5 ng/L for 2,6-DC-3-MBQ, and below DL to 9.1 ng/L for 2,3,6-TriCBQ. These authentic samples show DCBQ and DBBQ as the most abundant and frequently detectable HBQs. In addition, laboratory controlled experiments were performed to examine the formation of HBQs and their subsequent stability toward hydrolysis when the disinfectants, chlorine, chloramine, or ozone followed by chloramines, reacted with phenol (a known precursor) under various conditions

  20. Trade-offs in disinfection byproduct formation associated with precursor preoxidation for control of N-nitrosodimethylamine formation.

    Science.gov (United States)

    Shah, Amisha D; Krasner, Stuart W; Lee, Chih Fen Tiffany; von Gunten, Urs; Mitch, William A

    2012-05-01

    Chloramines in drinking water may form N-nitrosodimethylamine (NDMA). Various primary disinfectants can deactivate NDMA precursors prior to chloramination. However, they promote the formation of other byproducts. This study compared the reduction in NDMA formation due to chlorine, ozone, chlorine dioxide, and UV over oxidant exposures relevant to Giardia control coupled with postchloramination under conditions relevant to drinking water practice. Ten waters impacted by treated wastewater, poly(diallyldimethylammonium chloride) (polyDADMAC) polymer, or anion exchange resin were examined. Ozone reduced NDMA formation by 50% at exposures as low as 0.4 mg×min/L. A similar reduction in NDMA formation by chlorination required ∼60 mg×min/L exposure. However, for some waters, chlorination actually increased NDMA formation at lower exposures. Chlorine dioxide typically had limited efficacy regarding NDMA precursor destruction; moreover, it increased NDMA formation in some cases. UV decreased NDMA formation by ∼30% at fluences >500 mJ/cm(2), levels relevant to advanced oxidation. For the selected pretreatment oxidant exposures, concentrations of regulated trihalomethanes, haloacetic acids, bromate, and chlorite typically remained below current regulatory levels. Chloropicrin and trichloroacetaldehyde formation were increased by preozonation or medium pressure UV followed by postchloramination. Among preoxidants, ozone achieved the greatest reduction in NDMA formation at the lowest oxidant exposure associated with each disinfectant. Accordingly, preozonation may inhibit NDMA formation with minimal risk of promotion of other byproducts. Bromide >500 μg/L generally increased NDMA formation during chloramination. Higher temperatures increased NDMA precursor destruction by preoxidants but also increased NDMA formation during postchloramination. The net effect of these opposing trends on NDMA formation was water-specific.

  1. Formation and occurrence of new polar iodinated disinfection byproducts in drinking water.

    Science.gov (United States)

    Pan, Yang; Li, Wenbin; An, Hao; Cui, Hao; Wang, Ying

    2016-02-01

    During drinking water disinfection, iodinated disinfection byproducts (I-DBPs) can be generated through reactions between iodide, disinfectants, and natural organic matter. Drinking water I-DBPs have been increasingly attracting attention as emerging organic pollutants as a result of their significantly higher toxicity and growth inhibition than their chloro- and bromo-analogues. In this study, by adopting ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry precursor ion scan, multiple reaction monitoring, and product ion scan analyses, 11 new polar I-DBPs with confirmed structures and eight new polar I-DBPs with proposed structures were detected in simulated drinking water samples. Chloramination of simulated raw waters containing natural organic matter with higher aromaticity produced higher levels of new phenolic I-DBPs. Formation of new polar I-DBPs and total organic iodine (TOI) was most favored in chloramination, followed by chlorine dioxide treatment, and relatively minor in chlorination. Lower pH in chloramination substantially enhanced the formation of new polar I-DBPs and TOI. NH2Cl and dissolved organic nitrogen could be important nitrogen sources and precursors for formation of the two new nitrogenous phenolic I-DBPs. Notably, in tap water samples collected from nine major cities located in the Yangtze River Delta region of China, seven of the 11 new polar I-DBPs with confirmed structures were detected at levels from 0.11 to 28 ng/L, and the two new nitrogenous phenolic I-DBPs were ubiquitous with concentrations from 0.12 to 24 ng/L, likely due to the relatively high dissolved organic nitrogen levels in regional source waters.

  2. Characteristics of C-, N-DBPs formation from algal organic matter: role of molecular weight fractions and impacts of pre-ozonation.

    Science.gov (United States)

    Zhou, Shiqing; Zhu, Shumin; Shao, Yisheng; Gao, Naiyun

    2015-04-01

    Extracellular organic matter (EOM) and intracellular organic matter (IOM) of Microcystis aeruginosa have been reported to contribute to the formation of carbonaceous disinfection by-products (C-DBPs) and nitrogenous disinfection by-products (N-DBPs). Little is known about DBPs formation from different molecular weight (MW) fractions, especially for N-nitrosodimethylamine (NDMA). This study fractionated EOM and IOM into several MW fractions using a series of ultrafiltration membranes and is the first to report on the C-DBPs and N-DBPs formation from chlorination and chloramination of different MW fractions. Results showed that EOM and IOM were mainly distributed in low-MW (100 KDa) fractions. Additionally, the low-MW and high-MW fractions of EOM and IOM generally took an important part in forming C-DBPs and N-DBPs, either in chlorination or in chloramination. Furthermore, the effects of pre-ozonation on the formation of DBPs in subsequent chlorination and chloramination were also investigated. It was found that ozone shifted the high-MW fractions of EOM and IOM into lower MW fractions and increased the C-DBPs and N-DBPs yields to different degrees. As low-MW fractions are more difficult to remove than high-MW fractions by conventional treatment processes, therefore, activated carbon adsorption, nanofiltration (NF) and biological treatment processes can be ideal to remove the low-MW fractions and minimize the formation potential of C-DBPs and N-DBPs. Moreover, the use of ozone should be carefully considered in the treatment of algal-rich water.

  3. Preparation of iodine-123 labeled AM251: a potential SPECT radioligand for the brain cannabinoid CB1 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Ruoxi; Makriyannis, Alexandros [Connecticut Univ., Molecular and Cell Biology Dept., Storrs, CT (United States); Gatley, S.J. [Brookhaven National Lab., Medical Dept., Upton, NY (United States)

    1996-10-01

    We report the synthesis and labeling with iodine-123 of N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251). This compound is an analog of the recently described cannabinoid receptor antagonist, SR141716A, in which a 4-chlorophenyl group is replaced by 4-iodophenyl. Labeling in good yield (62%) and radiochemical purity (> 95%), and high specific activity (> 2500 Ci/mmol) was achieved by an iododestannylation reaction using the tributyltin precursor, no carrier added I-123 iodide, and chloramine-T. (author).

  4. Chemical Modification of Amino Acid Residues in Human Plasminogen

    Institute of Scientific and Technical Information of China (English)

    LIANG Fang; SUN Hong; ZHAO Cheng-guang; CUI Ting; HONG Shui-sheng; CHEN Jia; LIU Lan-ying

    2003-01-01

    The chemical modification of human plasminogen(HPg) was studied with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide(EDC), N-acetylimidazole(NAI), 1,2-cyclohexanedione(CHD), chloramine T(Ch-T) and N-bromosuccinimide(NBS) as modifying reagents at its carboxyl group, tyrosine, arginine, methionine and tryptophan residues, respectively. The results indicate that tyrosine and arginine residues are not essential for HPg activity, while carboxyl groups, methionine and tryptophan residues are important for the activity of HPg. The Keech and Farrant′s kinetic analysis reveals that one tryptophan residue, one methionine residue and two carboxyl groups are essential for HPg activity.

  5. Tissue culture of horse-radish (Cochlearia armoracia L. meristems: sterilization of buds and comparison of media

    Directory of Open Access Journals (Sweden)

    K. Górecka

    2015-06-01

    Full Text Available The attempt was made to cultivate horse-radish meristems taken from buds removed from roots. The lowest per cent of contamination was found after the buds had been soaiked in 80% ethanol for 6 minutes and then in 5%, 7.5% or 10% chloramine for 30, 30 or 15 minutes, respectively. Both agar media: Murashige-Skoog and Linsmaier-Skoog, were equally good, providing a moderate number of developing plants. The Linsmaier-Skoog medium was more satisfactory when solidified with agar; the results with liquid medium and filter-paper bridges were not as good.

  6. The tritium kinetic isotope effect for the iodination of L-(5-3H) -3-iodotyrosine

    International Nuclear Information System (INIS)

    The kinetic tritium isotope effect k(subH)/k(subT) for the iodination of L-(5-3H)-3-iodotyrosine at pH 7.5 was found to be 4.29 +-0.25 with molecular iodine and 4.50 +- 0.26 with chloramine-T/potassium iodide. This effect establishes that the rate-limiting step is proton removal by the general base. A novel method for measuring the fraction of tritiated water by high performance liquid chromatography is described

  7. Labelling of ochratoxins with sup 3 H or sup 125 I

    Energy Technology Data Exchange (ETDEWEB)

    Schmiedova, D.; Veres, K.; Cerny, B. (Ceskoslovenska Akademie Ved, Prague (Czechoslovakia). Ustav Nuklearni Biologie a Radiochemie); Ruprich, J. (Institut Hygieny a Epidemiologie, Prague (Czechoslovakia)); Nemecek, J. (Slovak Academy of Sciences, Prague (Czechoslovakia). Inst. of Microbiology)

    1989-01-01

    Catalytic hydrogenation of ochratoxin A by carrier-free tritium was used to prepare {sup 3}H-ochratoxin B with a high specific activity. Iodination of ochratoxin B by carrier-free Na {sup 125}I using the chloramine method yielded {sup 125}I-ochratoxin with a high specific activity. Another {sup 125}I-derivative of ochratoxin A was prepared by iodination of an ochratoxin A - L-tyrosine-methylester conjugate. All three radioactive preparations were found to be useful for radioimmunoassay. (author).

  8. Studies on the Radioimmunoassay of Human Growth Hormone - 1. Evaluation of the method of determination

    International Nuclear Information System (INIS)

    Utilizing the commercial radioimmunoassay kit, the author assayed HGH and evaluated the problems of the method. The method had the sensitivity of 0.5 mug/ml degree and could determine the plasma HGH concentration directly without the help of plasma extraction. Also it was specific for the HGH, when tested by a dilution method using test utilizing the plasma of the acromegalic patient. The author also obtained the 125I labelled HGH of specific activity of 156. 3 μCi/μg, performing the chloramine-T method.

  9. Isolation of a somatomedin binding protein from human preterm amniotic fluid: development of a radioimmunoassay

    International Nuclear Information System (INIS)

    This thesis investigates the nature and biological behaviour of a somatomedin binding protein, identified in preterm amniotic fluid (AF). For that purpose a double antibody radioimmunoassay was developed. Purified AF binding protein (AFBP) was iodinated by the chloramine-T method, and dilutions of partially purified AFBP were designated as the standard, with the results expressed in μg equivalent protein/ml. The sensitivity of the assay was improved by adoption of the nonequilibrium procedure. AFBP values were twice as high in preterm AF as in term AF. (Auth.)

  10. Qualitative and quantitative evaluation of donkeys responses to immunization by rabbits' IgG

    International Nuclear Information System (INIS)

    In this study two apparently healthy donkeys were immunized with highly pure rabbit's 1gG using a revised protocol. Qualitative test using the same immuno gen was done as a primary test to eva lute the immune system response. However, the same 1gG was iodinated with 125I using chloramine T method and the labeled 1gG was used to quantitatively study the immune response. The two donkeys showed good response with the younger one having the best response. The obtained donkey anti rabbit sera was used as separating agent for RIA assay for human PRL. (Author)

  11. optimization of insulin radioreceptor assay in human erythrocytes in normal and some disease status

    International Nuclear Information System (INIS)

    This study is concerned with the evaluation of a new optimized technique for the principle of chloramine-T method used for insulin iodination by 125I-radioisotope with some modifications. The modified procedure can be carried out under normal condition of room temperature, employed longer reaction times and omitted the addition of inorganic reducing salts, maintaining efficient iodination and avoiding denaturations to obtain labels of exceedingly high specific activity on a small quantities of insulin for in vitro usage in the investigation of human erythrocytes 125 I-insulin binding capacity in normal and some disease status

  12. Preparation of iodine-123 labeled AM251: a potential SPECT radioligand for the brain cannabinoid CB1 receptor

    International Nuclear Information System (INIS)

    We report the synthesis and labeling with iodine-123 of N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251). This compound is an analog of the recently described cannabinoid receptor antagonist, SR141716A, in which a 4-chlorophenyl group is replaced by 4-iodophenyl. Labeling in good yield (62%) and radiochemical purity (> 95%), and high specific activity (> 2500 Ci/mmol) was achieved by an iododestannylation reaction using the tributyltin precursor, no carrier added I-123 iodide, and chloramine-T. (author)

  13. Comparison of 131I-TYR3-octreotate and 131I-DOTA-TYR3-octreotate: The effect of DOTA on pharmacokinetics and stability

    International Nuclear Information System (INIS)

    The authors compared the biodistribution, and in vivo and in vitro stabilities of 131I-Tyr3-octreotate and 131I-DOTA-Tyr3-octreotate. The peptides were radioiodinated by the chloramine T method and high radiochemical yields were obtained (greater than 97%). Both labelled compounds showed high stability when incubated in human plasma at 37 deg C. The 131I-Tyr3-octreotate showed significant hepatic uptake and biliary excretion. The biodistribution of 131I-DOTA-Tyr3-octreotate, however, can be compared with the distribution of radiometal labelled octreotide analogues. (author)

  14. Comparison of specific radioactivities of human alpha-lactalbumin iodinated by three different methods

    Energy Technology Data Exchange (ETDEWEB)

    Thean, E.T. ( Monash Medical School, Prahran, Victoria (Australia))

    1990-08-01

    Radioiodination provides an extremely sensitive method for the detection of low levels of proteins. In the development of a sensitive radioimmunoassay for human alpha-lactalbumin (alpha-LA), the protein was labeled to high specific activity (approaching 2000 Ci/mmol) with lactoperoxidase, chloramine-T, and Iodogen. Despite high specific activities of the labeled protein by each method, there was a considerable difference in their binding affinity with monoclonal anti-human alpha-LA antibodies due to varying degrees of protein damage. Iodination of human alpha-LA with Iodogen resulted in labels of the highest specific activity and immunoreactivity with the monoclonal antibodies used.

  15. Die Auswirkung der Applikationszeit und Applikationsart eines selbst-ätzenden Adhäsivsystems auf die Randständigkeit von Klasse-V-Füllungen im Schmelz und Dentin

    OpenAIRE

    Lübke, Fabian Alexander

    2010-01-01

    The purpose of this study was to evaluate the effect of different application procedures, such as time and method of application, or number of the application layers, using a self-etching all-in-one adhesive on the marginal integrity of Class V cavities in enamel and dentin. Therefore standardized Class V cavities were labially prepared into 136 extracted human caries-free maxillary-middle incisors, stored in a 0.5 % chloramine solution. The extension of each cavity was 4.0 mm in coronal-a...

  16. The experience with setting-up radioimmunoassay for alpha-1 fetoprotein

    International Nuclear Information System (INIS)

    The decisive factor in the preparation of radioimmunological alpha-1-fetoprotein determination, provided sufficient commercial or own antisera and standards are available for calibration, is the quality of the preparation for labelling. Alpha-1-fetoprotein was separated by affinity chromatography using Sepharose with alpha-1-fetoprotein-bound antibodies. The isolates thus obtained were labelled with 125I using enzyme and chloramine T and Iodogen techniques. The labelled alpha-1-fetoprotein can be used for RIA. In view of reduced immunoreactivity of the preparation, however, the performance of the radioimmunological determination has so far not matched the quality of imported kits. The technique is currently being optimized. (author)

  17. Free radical reactions of monochloramine and hydroxylamine in aqueous solution

    International Nuclear Information System (INIS)

    The use of Advanced Oxidation Technologies to destroy organic contaminants in drinking water may be impacted by the presence of disinfection chemicals such as monochloramine (NH2Cl). To allow a quantitative evaluation of the effect of NH2Cl on the destruction of organics in water rate constants for its reaction with the hydrated electron, the hydroxyl radical and the hydrogen atom were determined in this study. The corresponding values of (2.2±0.2)x1010, (2.8±0.2)x109, and (1.2±0.1)x109 M-1 s-1, respectively, were incorporated into a kinetic computer model whose predictions were in good agreement with experimental chloramine removal under large scale, steady-state electron-beam irradiation conditions. Rate constants were also determined for the reaction of the hydroxyl radical and hydrogen atom with the chloramine hydration product hydroxylamine to supplement established literature data. Hydroxyl radical rate constants for the basic (NH2OH) and acidic (NH3OH+) forms were determined as (8.5±0.4)x109 and ≤5x107 M-1 s-1, respectively, while for hydrogen atom reaction, corresponding rate constants of (4.5±0.1)x107 and (3.6±1.5)x105 M-1 s-1 were found

  18. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Postigo, Cristina [Institute for Environmental Assessment and Water Research (IDAEA)—Spanish National Research Council (CID-CSIC), Barcelona (Spain); Richardson, Susan D., E-mail: richardson.susan@sc.edu [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC (United States)

    2014-08-30

    Graphical abstract: - Highlights: • Review of transformation pathways of pharmaceuticals during disinfection processes. • DBPs are formed with chlorine, chloramine, ozone, chlorine dioxide, UV, or UV/H{sub 2}O{sub 2}. • Chlorine reacts with amine and reduced sulfur groups and activated aromatic systems. • Chlorine dioxide and ozone react with electron-rich functional groups. • Potential health effects are noted for some pharmacuetical DBPs when available. - Abstract: Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment.

  19. Halonitromethanes formation in wastewater treatment plant effluents.

    Science.gov (United States)

    Song, Hocheol; Addison, Jesse W; Hu, Jia; Karanfil, Tanju

    2010-03-01

    Halonitromethanes (HNMs) constitute one class of emerging disinfection by-products with high potential health risks. This study investigated the formation and occurrence of HNMs under different disinfection scenarios and the presence of their precursors in municipal wastewater treatment plant (WWTPs) effluents. Formation potential tests performed on WWTP effluents revealed that HNM formation occurred in the order of ozonation-chlorination > ozonation-chloramination > chlorination > chloramination. Ozonation alone did not produce any HNM. Municipal WWTP effluents contained some reactive HNM precursors, possibly the by-products of biological treatment processes and/or some moiety of industry or household origin. No effects of nitrate on the formation of HNMs were observed in this study, and nitrification in WWTPs appears to remove appreciable portion of HNM precursors, especially those reactive to chlorine. UV disinfection using low pressure lamps in municipal WWTPs had negligible impact on HNM formation potential. HNM concentrations in the effluents of selected WWTPs were either non-detectable or less than minimum reporting level, except for one WWTP that gave trichloronitromethane concentrations in the range of 0.9-1.5 microg L(-1). No HNMs were observed in the effluents disinfected with UV radiation. Therefore, it appears the typical wastewater disinfection processes involving chlorination or UV treatment in WWTPs do not produce significant amounts of HNMs.

  20. Radioiodination and biological evaluation of levalbuterol as a new selective radiotracer. A β{sub 2}-adrenoceptor agonist

    Energy Technology Data Exchange (ETDEWEB)

    Sanad, Mahmoud Hamdi; Abelrahman, Mohamed Abdelmotelb; Marzook, Fawzy Mohamed Abdelmaged [Atomic Energy Authority, Cairo (Egypt). Radioisotopes Production and Radioactive Sources Div.

    2016-08-01

    Levalbuterol was successfully radiolabeled with iodine using chloramine-T as an oxidizing agent via an electrophilic substitution reaction. The reaction parameters that affecting the labeling yield such as levalbuterol concentration, chloramine-T concentration, pH of the reaction medium and reaction time were studied in details. The radiochemical yield was 97.5 ± 0.5% and the radioiodinated compound was separated by HPLC. In vitro studies showed that the iodinated levalbuterol was stable for up to 24 h. The biodistribution in experimental animals showed that the lung uptake was 68.18 ± 0.17% at 5 min post injection which decreased with time until reached to 18.7 ± 0.12% at 2 h which was higher than other recent developed radiopharmaceuticals for lung imaging. The clearance pathways from the mice appear to proceed via both hepatobiliary and renal pathways. Predosing the mice with cold levalbuterol reduced the lung uptake to 20 ± 1.3% and further confirms the high specificity and selectivity of {sup 125}I-levalbuterol for the lung.

  1. Rapid and efficient radiosynthesis of [{sup 123}I]I-PK11195, a single photon emission computed tomography tracer for peripheral benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Pimlott, Sally L. [Department of Clinical Physics, West of Scotland Radionuclide Dispensary, Western Infirmary, G11 6NT Glasgow (United Kingdom)], E-mail: s.pimlott@clinmed.gla.ac.uk; Stevenson, Louise [Department of Chemistry, WestCHEM, University of Glasgow, G12 8QQ Glasgow (United Kingdom); Wyper, David J. [Institute of Neurological Sciences, Southern General Hospital, G51 4TF Glasgow (United Kingdom); Sutherland, Andrew [Department of Chemistry, WestCHEM, University of Glasgow, G12 8QQ Glasgow (United Kingdom)

    2008-07-15

    Introduction: [{sup 123}I]I-PK11195 is a high-affinity single photon emission computed tomography radiotracer for peripheral benzodiazepine receptors that has previously been used to measure activated microglia and to assess neuroinflammation in the living human brain. This study investigates the radiosynthesis of [{sup 123}I]I-PK11195 in order to develop a rapid and efficient method that obtains [{sup 123}I]I-PK11195 with a high specific activity for in vivo animal and human imaging studies. Methods: The synthesis of [{sup 123}I]I-PK11195 was evaluated using a solid-state interhalogen exchange method and an electrophilic iododestannylation method, where bromine and trimethylstannyl derivatives were used as precursors, respectively. In the electrophilic iododestannylation method, the oxidants peracetic acid and chloramine-T were both investigated. Results: Electrophilic iododestannylation produced [{sup 123}I]I-PK11195 with a higher isolated radiochemical yield and a higher specific activity than achievable using the halogen exchange method investigated. Using chloramine-T as oxidant provided a rapid and efficient method of choice for the synthesis of [{sup 123}I]I-PK11195. Conclusions: [{sup 123}I]I-PK11195 has been successfully synthesized via a rapid and efficient electrophilic iododestannylation method, producing [{sup 123}I]I-PK11195 with a higher isolated radiochemical yield and a higher specific activity than previously achieved.

  2. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Review of transformation pathways of pharmaceuticals during disinfection processes. • DBPs are formed with chlorine, chloramine, ozone, chlorine dioxide, UV, or UV/H2O2. • Chlorine reacts with amine and reduced sulfur groups and activated aromatic systems. • Chlorine dioxide and ozone react with electron-rich functional groups. • Potential health effects are noted for some pharmacuetical DBPs when available. - Abstract: Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment

  3. Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors

    Science.gov (United States)

    Jolley, Katherine E

    2015-01-01

    Summary The continuous flow synthesis of a range of organic solutions of N,N-dialkyl-N-chloramines is described using either a bespoke meso-scale tubular reactor with static mixers or a continuous stirred tank reactor. Both reactors promote the efficient mixing of a biphasic solution of N,N-dialkylamine in organic solvent, and aqueous sodium hypochlorite to achieve near quantitative conversions, in 72–100% in situ yields, and useful productivities of around 0.05 mol/h with residence times from 3 to 20 minutes. Initial calorimetric studies have been carried out to inform on reaction exotherms, rates and safe operation. Amines which partition mainly in the organic phase require longer reaction times, provided by the CSTR, to compensate for low mass transfer rates in the biphasic system. The green metrics of the reaction have been assessed and compared to existing procedures and have shown the continuous process is improved over previous procedures. The organic solutions of N,N-dialkyl-N-chloramines produced continuously will enable their use in tandem flow reactions with a range of nucleophilic substrates. PMID:26734089

  4. Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors

    Directory of Open Access Journals (Sweden)

    A. John Blacker

    2015-12-01

    Full Text Available The continuous flow synthesis of a range of organic solutions of N,N-dialkyl-N-chloramines is described using either a bespoke meso-scale tubular reactor with static mixers or a continuous stirred tank reactor. Both reactors promote the efficient mixing of a biphasic solution of N,N-dialkylamine in organic solvent, and aqueous sodium hypochlorite to achieve near quantitative conversions, in 72–100% in situ yields, and useful productivities of around 0.05 mol/h with residence times from 3 to 20 minutes. Initial calorimetric studies have been carried out to inform on reaction exotherms, rates and safe operation. Amines which partition mainly in the organic phase require longer reaction times, provided by the CSTR, to compensate for low mass transfer rates in the biphasic system. The green metrics of the reaction have been assessed and compared to existing procedures and have shown the continuous process is improved over previous procedures. The organic solutions of N,N-dialkyl-N-chloramines produced continuously will enable their use in tandem flow reactions with a range of nucleophilic substrates.

  5. Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors.

    Science.gov (United States)

    Blacker, A John; Jolley, Katherine E

    2015-01-01

    The continuous flow synthesis of a range of organic solutions of N,N-dialkyl-N-chloramines is described using either a bespoke meso-scale tubular reactor with static mixers or a continuous stirred tank reactor. Both reactors promote the efficient mixing of a biphasic solution of N,N-dialkylamine in organic solvent, and aqueous sodium hypochlorite to achieve near quantitative conversions, in 72-100% in situ yields, and useful productivities of around 0.05 mol/h with residence times from 3 to 20 minutes. Initial calorimetric studies have been carried out to inform on reaction exotherms, rates and safe operation. Amines which partition mainly in the organic phase require longer reaction times, provided by the CSTR, to compensate for low mass transfer rates in the biphasic system. The green metrics of the reaction have been assessed and compared to existing procedures and have shown the continuous process is improved over previous procedures. The organic solutions of N,N-dialkyl-N-chloramines produced continuously will enable their use in tandem flow reactions with a range of nucleophilic substrates.

  6. Breakpoint chlorination curves of greywater.

    Science.gov (United States)

    March, J G; Gual, M

    2007-08-01

    A study on chlorination of raw greywater with hypochlorite is reported in this paper. Samples were chlorinated in a variety of conditions, and residual chlorine (Cl2) was measured spectrophotometrically. For each sample, the chlorination curve (chlorine residuals versus chlorine dose) was obtained. Curves showed the typical hump-and-dip profile attributable to the formation and destruction of chloramines. It was observed that, after reactions with strong reductants and chloramines-forming compounds, the remaining organic matter exerted a certain demand of chlorine. The evolution of chlorination curves with addition of ammonia and dodecylbencene sulfonate sodium salt and with dilution of the greywater sample were studied. In addition, chlorination curves at several contact times have been obtained, resulting in slower chlorine decay in the hump zone than in the dip zone. In addition, the decay of coliforms in chlorinated samples was also investigated. It was found that, for a chlorination dosage corresponding to the maximum of the hump zone (average 8.9 mg Cl2/ L), samples were negative in coliforms after 10 to 30 minutes of contact time. After-growth was not observed within 3 days after chlorination. Implications in chlorination treatments of raw greywater can be derived from these results. PMID:17824528

  7. Effect of Taurine on Acinar Cell Apoptosis and Pancreatic Fibrosis in Dibutyltin Dichloride-induced Chronic Pancreatitis

    Directory of Open Access Journals (Sweden)

    Sawa,Kiminari

    2012-08-01

    Full Text Available The relationship between pancreatic fibrosis and apoptosis of pancreatic acinar cells has not been fully elucidated. We reported that taurine had an anti-fibrotic effect in a dibutyltin dichloride (DBTC-chronic pancreatitis model. However, the effect of taurine on apoptosis of pancreatic acinar cells is still unclear. Therefore, we examined apoptosis in DBTC-chronic pancreatitis and in the AR42J pancreatic acinar cell line with/without taurine. Pancreatic fibrosis was induced by a single administration of DBTC. Rats were fed a taurine-containing diet or a normal diet and were sacrificed at day 5. The AR42J pancreatic acinar cell line was incubated with/without DBTC with taurine chloramines. Apoptosis was determined by using terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL assay. The expression of Bad and Bcl-2 proteins in the AR42J cells lysates was detected by Western blot analysis. The apoptotic index of pancreatic acinar cells in DBTC-administered rats was significantly increased. Taurine treatment inhibited pancreatic fibrosis and apoptosis of acinar cells induced by DBTC. The number of TUNEL-positive cells in the AR42J pancreatic acinar cell lines was significantly increased by the addition of DBTC. Incubation with taurine chloramines ameliorated these changes. In conclusion, taurine inhibits apoptosis of pancreatic acinar cells and pancreatitis in experimental chronic pancreatitis.

  8. Studies on human proinsulin.C-peptide radioimmunoassay method

    International Nuclear Information System (INIS)

    125I-labelled human.C-peptide was prepared by the chloramin T method, the enzymic method and the active ester method, respectively. Using respective 125I-labelled human.C-peptides in human proinsulin.C-peptide RIA, we compared the binding (B0/T %) to antibody, displacement by standard human.C-peptide, recovery, and stability. The usable 125I-labelled antigen for human proinsulin.C-peptide RIA could be prepared by the chloramin T method and the enzymic method which labelled 125I to tyrosyl human proinsulin connecting peptide, and by an active ester method which conjugates 125I-labelled active ester to human proinsulin connecting peptide. No differences among those 125I-labelled antigens were observed in displacement (B/B0 %) by standard human.C-peptide or the recovery test. In the case of constant preparation of 125I-labelled antigen for RIA, the enzymic method was the best from the viewpoint that reaction ratio is stable and the stability of B0/T % was good. (auth.)

  9. Preparation of 131I-epidepride and biodistribution study in SD rats

    International Nuclear Information System (INIS)

    The purpose is to study the preparation and biodistribution in animals of dopamine D2 receptor ligand 131I-epidepride. Epidepride was 131I radioiodinated with hydroperoxide or chloramine-T method. The purity and stability of 131I-epidepride were studied by HPLC and TLC, the dynamic distribution in brain and critical organs of SD rats were studied. The radiolabelling yields of 131I-epidepride were 97.4% and 52.9% respectively. With no more purification, the hydroperoxide method is better than the chloramine-T method. After 4 hours in room temperature, the radiochemical purity of 131I-epidepride was still over 90%. The striatum uptake was good, the striatum/cerebellum ratio reached 237:1 at 320 min. Among the critical organs, lung had the first and the highest uptake. All organs had quick clearance (T1/2131I-epidepride has a high striatum uptake and a high striatum/cerebellum ratio. 131I-epidepride is a good dopamine D2 receptor agent

  10. Optimization of the preparation conditions of radioiodoepidepride. A dopamine D2receptor antagonist radioligand

    International Nuclear Information System (INIS)

    [125I]iodepidepride, (s)-(-)-[(1-ethyl-2-pyrrolidinyl)methyl]-5-[125I]-iodo-2,3- dimethoxybenzamide is the iodine substituted analogue of isoremoxipride, both of which are very potent dopamine D2-antagonists. Epidepride was radioiodinated using different oxidizing agents such as chloramine-T, iodogen, iodogen glass frit and hydrogen peroxide. Chloramine-T is a powerful oxidizing agent compared to both iodogen and hydrogen peroxide so that the side products, especially the chlorinated epidepride, decreases the radiochemical yield. This chlorinated epidepride is minimized in the case of iodogen and iodogen glass frit and are not observed in case of the non-chlorinated oxidizing agent hydrogen peroxide. TLC and HPLC were used to analyze the reaction components and to estimate both the radiochemical yield and purity. The reaction parameters such as reaction time, pH, epidepride and oxidizing agent concentrations and the stabilty of the final product were studied to optimize the radiochemical yield and purity. The optimized radiochemical yield was about 90% and the radiochemical purity of the final product was 99.9%. (author)

  11. [Chlorination byproducts formation potentials of typical nitrogenous organic compounds in water].

    Science.gov (United States)

    Xu, Qian; Xu, Bin; Qin, Cao; Xia, Sheng-Ji; Gao, Nai-Yun; Tian, Fu-Xiang; Li, Da-Peng

    2011-07-01

    Twelve typical nitrogenous organic compounds including herbicides, pesticides, amino acids, industrial products etc in polluted raw water were selected to investigate formation of typical carbonaceous and nitrogenous DBPs during chlorination and chloramination. To indentify the formation mechanism of carbonaceous and nitrogenous disinfection byproducts from nitrogenous chemicals, chlorination and chloroamination of urea herbicides, triazine herbicides, amino acid, and other compounds were investigated. As a result, the potential precursors for different DBPs were defined as well. It has been identified that widely used urea herbicides could produce as many as 9 specific DBPs. The chlorotoluron shows highest reactivity and yields chloroform (CF), monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), 1,1-dichloro-acetone (1,1-DCP), 1,1,1-trichloro-acetone (1,1,1-TCP), chloropicrin (NTCM), dichloro-acetonitrile (DCAN), dimethylnitrosamine (NDMA). The results indicated that aldicarb and dinoseb are important precursors of CF, DCAA, MCAA, NTCM as well. High concentrations of CF and DCAA were found during L-tryptophan chlorination. Furthermore, DBPs formation pathways and mechanisms were suggested during chlorination and chloramination of chlorotoluron, ametryn, dinoseb L-tryptophan.

  12. 基于大型工程实例评价两种常用的消毒方式%Evaluation of Two Disinfection Processes on the Basis of Large-scale Engineering Application

    Institute of Scientific and Technical Information of China (English)

    吴仲斯; 阳宇恒; 靳小虎; 周勤; 蔡展航

    2015-01-01

    In order to evaluate the effectiveness of two different types of disinfection processes, the production of disinfection byproducts and relevant capital costs for a water treatment plant, named A Water Treatment Plant, located in the south part of China, water quality analysis and determination of chlorine usage for the treated water by the two processes are conducted. It has been concluded that chloramine and chlorine are both effective. The concentration of chloroform and free chlorine in the water are rapidly increased after chlorine treatment. Additionally, the costs of chlorine are 70% of chloramine costs, which are relatively lower.%以某南方大都市A水厂为研究对象,通过对实际运行中消毒工艺变更前后的出厂水和管网水的水质和耗氯量进行分析,评价两种消毒工艺的消毒效果、副产物产生情况以及运营成本。结果表明:氯胺和液氯两种消毒剂均有良好的消毒效果;使用液氯后水中的三氯甲烷和游离氯的含量骤增;液氯消毒成本较低,约为氯胺消毒的70%。

  13. Disinfection byproduct formation from lignin precursors.

    Science.gov (United States)

    Hua, Guanghui; Kim, Junsung; Reckhow, David A

    2014-10-15

    Lignin is the most abundant aromatic plant component in terrestrial ecosystems. This study was conducted to determine the contribution of lignin residues in natural water to the formation of disinfection byproducts (DBPs) in drinking water. We investigated the formation of different classes of DBPs from lignin model compounds, lignin polymers, and humic substances using two common disinfection techniques, chlorination and chloramination. The contributions of lignin to the overall formation of DBPs from these organic products were determined based on the observed abundances of individual lignin phenols and their DBP yields. Model lignin phenols generally produced higher trichloroacetic acid (TCAA) yields than chloroform and dichloroacetic acid (DCAA) during chlorination. Lignin phenols generally produced higher DBP yields but lower percentages of unknown total organic halogen compared to bulk humic substances and lignin polymers. The relative significance of lignin phenols as chlorination DBP precursors generally follows the order of TCAA > DCAA&chloroform. The relative significance of lignin phenols to DBP formation by chloramination follows the order: TCAA > DCAA&DCAN > chloroform. Overall, lignin phenols are more important as TCAA precursors than as chloroform and DCAA precursors.

  14. The drinking water treatment process as a potential source of affecting the bacterial antibiotic resistance.

    Science.gov (United States)

    Bai, Xiaohui; Ma, Xiaolin; Xu, Fengming; Li, Jing; Zhang, Hang; Xiao, Xiang

    2015-11-15

    Two waterworks, with source water derived from the Huangpu or Yangtze River in Shanghai, were investigated, and the effluents were plate-screened for antibiotic-resistant bacteria (ARB) using five antibiotics: ampicillin (AMP), kanamycin (KAN), rifampicin (RFP), chloramphenicol (CM) and streptomycin (STR). The influence of water treatment procedures on the bacterial antibiotic resistance rate and the changes that bacteria underwent when exposed to the five antibiotics at concentration levels ranging from 1 to 100 μg/mL were studied. Multi-drug resistance was also analyzed using drug sensitivity tests. The results indicated that bacteria derived from water treatment plant effluent that used the Huangpu River rather than the Yangtze River as source water exhibited higher antibiotic resistance rates against AMP, STR, RFP and CM but lower antibiotic resistance rates against KAN. When the antibiotic concentration levels ranged from 1 to 10 μg/mL, the antibiotic resistance rates of the bacteria in the water increased as water treatment progressed. Biological activated carbon (BAC) filtration played a key role in increasing the antibiotic resistance rate of bacteria. Chloramine disinfection can enhance antibiotic resistance. Among the isolated ARB, 75% were resistant to multiple antibiotics. Ozone oxidation, BAC filtration and chloramine disinfection can greatly affect the relative abundance of bacteria in the community.

  15. Contribution of N-Nitrosamines and Their Precursors to Domestic Sewage by Greywaters and Blackwaters.

    Science.gov (United States)

    Zeng, Teng; Mitch, William A

    2015-11-17

    N-nitrosamines and their precursors are significant concerns for water utilities exploiting wastewater-impacted water supplies, particularly those practicing potable reuse of wastewater. Previous efforts to identify specific precursors in municipal wastewater accounting for N-nitrosamine formation have met with limited success. As an alternative, we quantified the relative importance of greywater (i.e., shower, kitchen sink, bathroom washbasin, and laundry) and blackwater (i.e., urine and feces) streams in terms of their loadings of ambient specific and total N-nitrosamines and chloramine-reactive and ozone-reactive N-nitrosamine precursors to domestic sewage. Accounting for the volume fractions of individual greywater and blackwater streams, laundry water represented the most significant source of N-nitrosamines and their precursors, followed by shower water and urine. Laundry water was particularly important for ozone-reactive N-nitrosamine precursors, accounting for ∼99% of N-nitrosodimethylamine (NDMA) precursors and ∼69% of precursors for other uncharacterized N-nitrosamines. For the other greywater streams, consumer products contributed additional N-nitrosamines and precursors, but the remarkable uniformity across different products suggested the importance of common macroconstituents. The consumption of a standard dose of the antacid ranitidine substantially increased NDMA and its chloramine-reactive precursors in urine. Nevertheless, nearly 40% of the American population would need to consume ranitidine daily to match the NDMA loadings from laundry water. PMID:26496512

  16. Nitrogenous disinfection byproducts in English drinking water supply systems: Occurrence, bromine substitution and correlation analysis.

    Science.gov (United States)

    Bond, Tom; Templeton, Michael R; Mokhtar Kamal, Nurul Hana; Graham, Nigel; Kanda, Rakesh

    2015-11-15

    Despite the recent focus on nitrogenous disinfection byproducts in drinking water, there is limited occurrence data available for many species. This paper analyses the occurrence of seven haloacetonitriles, three haloacetamides, eight halonitromethanes and cyanogen chloride in 20 English drinking water supply systems. It is the first survey of its type to compare bromine substitution factors (BSFs) between the haloacetamides and haloacetonitriles. Concentrations of the dihalogenated haloacetonitriles and haloacetamides were well correlated. Although median concentrations of these two groups were lower in chloraminated than chlorinated surface waters, median BSFs for both in chloraminated samples were approximately double those in chlorinated samples, which is significant because of the higher reported toxicity of the brominated species. Furthermore, median BSFs were moderately higher for the dihalogenated haloacetamides than for the haloacetonitriles. This indicates that, while the dihalogenated haloacetamides were primarily generated from hydrolysis of the corresponding haloacetonitriles, secondary formation pathways also contributed. Median halonitromethane concentrations were remarkably unchanging for the different types of disinfectants and source waters: 0.1 μg · mgTOC(-1) in all cases. Cyanogen chloride only occurred in a limited number of samples, yet when present its concentrations were higher than the other N-DBPs. Concentrations of cyanogen chloride and the sum of the halonitromethanes were not correlated with any other DBPs.

  17. Monochloramine Cometabolism by Mixed-Culture Nitrifiers under Drinking Water Conditions.

    Science.gov (United States)

    Maestre, Juan P; Wahman, David G; Speitel, Gerald E

    2016-06-21

    Chloramines are the second most used secondary disinfectant by United States water utilities. However, chloramination may promote nitrifying bacteria. Recently, monochloramine cometabolism by the pure culture ammonia-oxidizing bacteria, Nitrosomonas europaea, was shown to increase monochloramine demand. The current research investigated monochloramine cometabolism by nitrifying mixed cultures grown under more relevant drinking water conditions and harvested from sand-packed reactors before conducting suspended growth batch kinetic experiments. Four types of batch kinetic experiments were conducted: (1) positive controls to estimate ammonia kinetic parameters, (2) negative controls to account for biomass reactivity, (3) utilization associated product (UAP) controls to account for UAP reactivity, and (4) cometabolism experiments to estimate cometabolism kinetic parameters. Kinetic parameters were estimated in AQUASIM with a simultaneous fit to the experimental data. Cometabolism kinetics were best described by a first-order model. Monochloramine cometabolism kinetics were similar to those of ammonia metabolism, and monochloramine cometabolism accounted for 30% of the observed monochloramine loss. These results demonstrated that monochloramine cometabolism occurred in mixed cultures similar to those found in drinking water distribution systems; therefore, monochloramine cometabolism may be a significant contribution to monochloramine loss during nitrification episodes in drinking water distribution systems. PMID:27196729

  18. Labeling Lanreotide with 125I and 188Re

    International Nuclear Information System (INIS)

    Lanreotide is a new somatostatin analogue. It can bind to human somatostatin receptor (hSSTR) subtype 2 through 5 with high affinity and to hSSTR subtype I with low affinity. We investigate labeling condition, quality control and stability in vitro of 125I-Lanreotide and 188Re-lanreotide respectively. (A) Lanreotide is labeled with 125I using Chloramine T. The effect of reaction condition (such as reaction time, pH value, Lanreotide amount, quantity of Chloramine T and reaction volume) on labeling yield is investigated in detail. (B) The labeling yield and radiochemical purity (RP) is measured with paper chromatography (PC) and Sep-Pak C18 Cartridge. (C) The stability of 125I-Lanreotide in vitro is investigated by labeling compound incubating for 48 hours at 37 deg C in the 0.9% sodium chloride solution and RP is tested by PC at specific time intervals. (D) Lanreotide is labeled directly with 188Re via the mixture of citrate and tartate using stannous chloride as reduced agent. The influence of reaction conditions such as pH, temperature, amount of stannous chloride, amount of Lanreotide and reaction time on labeling yield is investigated in detail. At the time, the stability in vitro quality control and animal test are evaluated

  19. Simultaneous Control of Microorganisms and Disinfection By-products by Sequential Chlorination

    Institute of Scientific and Technical Information of China (English)

    CHAO CHEN; XIAO-JIAN ZHANG; WEN-JIE HE; HONG-DA HAN

    2007-01-01

    Objective To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. Methods Pilot tests of this sequential chlorination were carried out in a drinking water plant. Results The sequential chlorination disinfection process had the same or better efficiency on microbe (including virus)inactivation compared with the free chlorine disinfection process. There seemed to be some synergetic disinfection effect between free chlorine and monochloramine because they attacked different targets. The sequential chlorination disinfection process resulted in 35.7%-77.0% TTHM formation and 36.6%-54.8% THAA5 formation less than the free chlorination process.The poorer the water quality was, the more advantage the sequential chlorination disinfection had over the free chlorination.Conclusion This process takes advantages of free chlorine's quick inactivation of microorganisms and chloramine's low disinfection by-product (DBP) yield and long-term residual effect, allowing simultaneous control of microbes and DBPs in an effective and economic way.

  20. Enhanced formation of disinfection byproducts in shale gas wastewater-impacted drinking water supplies.

    Science.gov (United States)

    Parker, Kimberly M; Zeng, Teng; Harkness, Jennifer; Vengosh, Avner; Mitch, William A

    2014-10-01

    The disposal and leaks of hydraulic fracturing wastewater (HFW) to the environment pose human health risks. Since HFW is typically characterized by elevated salinity, concerns have been raised whether the high bromide and iodide in HFW may promote the formation of disinfection byproducts (DBPs) and alter their speciation to more toxic brominated and iodinated analogues. This study evaluated the minimum volume percentage of two Marcellus Shale and one Fayetteville Shale HFWs diluted by fresh water collected from the Ohio and Allegheny Rivers that would generate and/or alter the formation and speciation of DBPs following chlorination, chloramination, and ozonation treatments of the blended solutions. During chlorination, dilutions as low as 0.01% HFW altered the speciation toward formation of brominated and iodinated trihalomethanes (THMs) and brominated haloacetonitriles (HANs), and dilutions as low as 0.03% increased the overall formation of both compound classes. The increase in bromide concentration associated with 0.01-0.03% contribution of Marcellus HFW (a range of 70-200 μg/L for HFW with bromide = 600 mg/L) mimics the increased bromide levels observed in western Pennsylvanian surface waters following the Marcellus Shale gas production boom. Chloramination reduced HAN and regulated THM formation; however, iodinated trihalomethane formation was observed at lower pH. For municipal wastewater-impacted river water, the presence of 0.1% HFW increased the formation of N-nitrosodimethylamine (NDMA) during chloramination, particularly for the high iodide (54 ppm) Fayetteville Shale HFW. Finally, ozonation of 0.01-0.03% HFW-impacted river water resulted in significant increases in bromate formation. The results suggest that total elimination of HFW discharge and/or installation of halide-specific removal techniques in centralized brine treatment facilities may be a better strategy to mitigate impacts on downstream drinking water treatment plants than altering

  1. Clinical scale preparation and evaluation of 131I-Rituximab for Non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Radioimmunotherapy (RIT) with anti CD20 MoAb conjugated to a β- emitting radioisotope like 131I or 90Y has the added advantage of delivering radiation not only to tumor cells that bind the antibody but also due to a crossfire effect, to neighboring tumor cells inaccessible to the antibody. In order to make available an indigenous radioimmunotherapeutic agent for Non Hodgkin's Lymphoma (NHL), radioiodinated Rituximab has been prepared and evaluated at a clinical scale. Radioiodination of Rituximab was performed by the conventional Chloramine T method using 7.4 GBq Na131I in a lead shielded plant. Six batches of radioiodination were prepared and characterized by electrophoresis and HPLC to evaluate the reproducibility of the product. The product remained stable retaining the radiochemical purity > 95% upto 5 days after radioiodination. In vitro cell binding studies and biodistribution studies in normal Swiss mice have indicated the potential of this molecule as a radioimmunotherapeutic agent for NHL. (orig.)

  2. Recent advances in drinking water disinfection: successes and challenges.

    Science.gov (United States)

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    , it is recommended that water disinfection should never be compromised by attempting to control DBPs. The reason for this is that the risks of human illness and death from pathogens in drinking water are much greater than the risks from exposure to disinfectants and disinfection by-products. Nevertheless, if DBP levels exceed regulatory limits, strategies should focus on eliminating organic impurities that foster their formation, without compromising disinfection. As alternatives to chlorine, disinfectants such as chloramines, ozone, chlorine dioxide, and UV disinfection are gaining popularity. Chlorine and each of these disinfectants have individual advantage and disadvantage in terms of cost, efficacy-stability, ease of application, and nature of disinfectant by-products (DBPs). Based on efficiency, ozone is the most efficient disinfectant for inactivating bacteria, viruses, and protozoa. In contrast, chloramines are the least efficient and are not recommended for use as primary disinfectants. Chloramines are favored for secondary water disinfection, because they react more slowly than chlorine and are more persistent in distribution systems. In addition, chloramines produce lower DBP levels than does chlorine, although microbial activity in the distribution system may produce nitrate from monochloramine, when it is used as a residual disinfectant, Achieving the required levels of water quality, particularly microbial inactivation levels, while minimizing DBP formation requires the application of proper risk and disinfection management protocols. In addition, the failure of conventional treatment processes to eliminate critical waterborne pathogens in drinking water demand that improved and/or new disinfection technologies be developed. Recent research has disclosed that nanotechnology may offer solutions in this area, through the use of nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes, and nanoparticle-enhanced filtration.

  3. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht; Zortea, R.; Piketty, A.;

    2013-01-01

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported...... to be found in swimming pool water: chloroform, bromodichloromethane, dibromochloromethane, bromoform, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetronitrile, trichloroacetonitrile, trichloronitromethane, dichloropropanone, trichloropropanone, and chloral hydrate. First order photolysis constants...... in a swimming pool. In an investigated public pool the UV dose was equivalent to an applied electrical energy of 1.34 kWh m− 3 d− 1 and the UV dose required to removed 90% of trichloronitromethane was 0.4 kWh m− 3 d− 1, while 2.6 kWh m− 3 d− 1 was required for chloral hydrate and the bromine containing...

  4. Standardization of human thyrotropin radioimmunoassay and its application to the purification of this hormone to the preparation of the assay reagents

    International Nuclear Information System (INIS)

    The various steps that are necessary for setting up the thyrotropin radioimmunoassay are presented below. Radioiodination was carried out through the Chloramine T method and the labeled purification performed on Sephadex G-100. Purification of human thyrotropin from side fractions obtained during the purification of growth hormone was carried out in order to obtain a pure reagent for use in the radioimmunoassay. The employment of the hormone obtained was evaluated as the radioimmunoassay tracer in comparison with that prepared from the hormone received from the NIDDKD, U.S.A. The results indicated that although it was not possible to obtain a hormone with a purity degree adequate to be used as the tracer, enough experience was acquired for the isolation of thyrotropin. (author)

  5. Study and development of a radioimmunoassay of antidiuretic hormone sensitive at 10/sup -12/M

    Energy Technology Data Exchange (ETDEWEB)

    Caillens, H.; Rousselet, F. (Faculte des Sciences Pharmaceutiques, (France)); Paillard, F. (Hopital Tenon, Paris (France))

    1982-07-01

    A radioimmunoassay of antidiuretic hormone is described. The antiserum was obtained by immunization of rabbits with lysine vasopressin conjugated to hemocyanine. The specificity of the antibody was selective and directed against the pentapeptide ring of the vasopressin molecule: oxytocin showed no cross-reactivity at 10/sup -9/M. The labelled hormone (/sup 125/I-AVP) prepared using the chloramine-T method had a high specific activity (1860 Ci/mmol). Incubation was performed in an equilibrium system. Comparative studies of different separation methods of bounds and free /sup 125/I-AVP showed that the sensitivity and the precision of the standard curve were better using charcoal dextran. The limit of detection of the assay was 1,6 pg per ml.

  6. Homologous radioimmunoassay of human prolactin

    International Nuclear Information System (INIS)

    Gelfiltration on Sephadex G-75 showed a heterogenity of prolactin in serum of patients with prolactinoma and in culture medium of a prolactinoma. Serum of patients with prolactinoma and culture medium of a prolactinoma were examined as possible sources of prolactin by gel filtration and ion exchange chromatography. Polyacrylamide electrophoresis revealed both preparations as contaminated by other proteins. Nevertheless prolactin isolated form culture medium of a prolactinoma is good enough as a tracer in our radioimmunoassay because contaminating proteins in this preparation do not inferfere in our system. An hPRL antiserum created in a rabbit against a crude fraction of human serum of a patient with prolactinoma was tested by titration, saturation studies, and ion exchange chromatography. In comparison with lactoperoxidase-iodinated prolactin Chloramine T iodinated prolactin showed higher loss of immunochemical properity, however higher specific activity. Specifity and precision in our radioimmunoassay system were described and the conditions of optimal sensitivity in our assay were evaluated. (orig.)

  7. Rapid method for the preparation of 125I-labelled human growth hormone for receptor studies, using reverse-phase high performance liquid chromatography

    International Nuclear Information System (INIS)

    Human growth hormone was labelled with 125 Iodine by the stoichiometric modification of the chloramine-T method to a specific activity of 50-80 microCi/microgram, and the iodinated mixture was purified by reverse-phase high performance liquid chromatography using a C18 column (SynChropak RP-P) and a linear gradient. Compared with the usual Sephadex G-100 chromatography, HPLC gave a much better separation, with a higher yield and a considerably reduced analysis time (30 min vs 5 h). The [125I]-labelled preparation had normal binding to IM-9 lymphocyte receptors. The maximum bindability of the HPLC-purified preparation approximated 90%, which is the best value so far reported for human growth hormone. It is concluded that HPLC is a fast, convenient and reproducible method for obtaining an improved [125I]-labelled human growth hormone for receptor studies

  8. Development of the kits for RIA simultaneous determination of polypeptide hormones

    International Nuclear Information System (INIS)

    A simple and universal modification of chloramine T technique has been developed for the radioactive iodination of several polypeptide hormones such as insulin, human growth hormone (HGH), human TSH, synthetic human gastrin and beta-endorphine. The prepared products proved to have good immunoreactivity suitable for RIA purposes. The technique is inexpensive and quick. A new procedure has also been worked out utilizing horse myeloperoxidase in solid state as catalyser. The hormones iodinated with this technique show better parameters (e.g. longer stability, better binding to antibody, more favourable adsorption on dextran-coated charcoal); however the specific activities achieved were lower. The possibilities of simultaneous measurement of insulin and HGH have been studied. In this connection, a comparatively simple method for the determination of the endogenous anti-insulin antibodies was developed and used for the control of patients with diabetes and for the checking of new insulin preparations. However, the technique requires relatively sophisticated equipment and computerized calculations

  9. Spectrophotometric determination of azathioprine in pharmaceutical formulations.

    Science.gov (United States)

    Lakshmi, C S; Reddy, M N

    1998-12-01

    Four simple and sensitive visible spectrophotometric methods (A-D) have been described for the assay of azathioprine (ATP) either in pure form or in pharmaceutical formulations. Methods A and B are based on the oxidation of ATP with excess N-bromosuccinimide (NBS) or chloramine-T (CAT) and determining the consumed NBS or CAT with a decrease in colour intensity of celestine blue (CB) (method A) or gallocyanine (GC) (method B), respectively. Methods C and D are based on the diazotisation of reduced azathioprine (RATP) with excess nitrous acid and estimating either the consumed nitrous acid (HNO(2)) with cresyl fast violet acetate (CFVA) (method C) or by coupling reaction of the diazonium salt formed with N-1-naphthyl ethylene diamine dihydrochloride (NED) (method D). All of the variables have been optimized and the reactions presented. The concentration measurements are reproducible within a relative standard deviation of 1.0%. Recoveries are 99.2-100.3%. PMID:18967434

  10. Invertase immobilization by adsorption on polymer microspheres studied by radioiodination technique

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Alvaro A.A. de [Universidade Federal de Itajuba, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Fisica e Quimica]. E-mail: alencar@unifei.edu.br; Pontin, Luiz F. [Universidade Federal de Itajuba, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Matematica e Computacao]. E-mail: pontin@unifei.edu.br; Higa, Olga Z.; Ribela, Maria Tereza C.P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Biologia Molecular]. E-mail: ozahiga@ipen.br; Tomotani, Ester J.; Vitolo, Michele [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Tecnologia Bioquimico-Farmaceutica]. E-mail: michenzi@usp.br

    2005-07-01

    In this paper, we report the study of the diffusion behavior of invertase onto polystyrene-divinylbenzene (PS-DVB) microspheres. To detect the surface concentration of protein adsorbed on the microspheres, the chloramine-T method was used to label invertase and has been applied to the study of protein sorption properties on the microspheres. The sorption isotherms and the diffusion coefficient (D{sub f}) were computed from experimental results and the concentration of bound invertase was determined in terms of the Fick's law. The Hill equation was applied to the data and the binding capacity of the microspheres were estimated. The results of adsorption show that the radiolabelling invertase method are efficacious at the protein surface concentration detection and can be used to investigate the enzyme immobilization by sorption properties of polymer microspheres. (author)

  11. Development of glycoside-bound radiopharmaceuticals; Novel radioiodination method for digoxin

    Energy Technology Data Exchange (ETDEWEB)

    Takemura, Yasutaka; Dote, Nobuhito; Taniuchi, Hideyuki; Iijima, Naoko; Yokoyama, Akira (Kyoto Univ. (Japan). Faculty of Pharmaceutical Science); Fujibayashi, Yasuhisa; Konishi, Junji

    1994-01-01

    We combined 2-hydroxy-3-methylbenzoylhydrazide (HMBH) with glycosides as a novel method for the radioiodination of physiologically active glycosides. This method was tested using digoxin, which is one of the cardiac glycosides. A digoxin-HMBH conjugate was synthesized by periodate cleavage of the third sugar ring, and was readily radiolabelled with Na[[sup 125]I] by the chloramine-T method. [sup 125]I labelled digoxin-HMBH conjugate retained Na[sup +], K[sup +]-ATPase binding in vivo and in vitro, and also retained immunoreactivity to an anti-digoxin antibody. Thus, this [sup 125]I labelled digoxin-HMBH conjugate represents a potential radiopharmaceutical for Na[sup +], K[sup +]-ATPase imaging, as well as for the radioimmunoassay of digoxin. (author).

  12. A radioimmunoassay for chicken avidin

    International Nuclear Information System (INIS)

    A double-antibody solid-phase radioimmunoassay for chicken avidin is reported. Avidin was labelled with 125I by the chloramine-T method. The bound and free avidin were separated with a second antibody bound to a solid matrix. In the logit-log scale the standard curve was linear from 1-2 to 100-200ng of avidin/ml. Cross-reaction of ovalbumin was less than 0.015%. Saturation of biotin-binding sites of avidin with an excess of biotin decreased radioimmunoassay values by about 15%. Recovery studies indicated that avidin can be assayed from all chicken tissues studied with radioimmunoassay, whereas the [14C]biotin/bentonite method gave poor recoveries for avidin in the liver and kidney. Radioimmunoassay and the [14C]biotin/bentonite method gave similar concentrations for oviduct avidin. (author)

  13. Physico-chemical technologies for nitrogen removal from wastewaters: a review

    Directory of Open Access Journals (Sweden)

    Andrea G. Capodaglio

    2015-07-01

    Full Text Available The paper examines the main physico-chemical processes for nitrogen removal from wastewaters, considering both those that have been long known and still widely applied at the industrial scale, and those that are still at the research level. Special attention is paid to the latest technological developments, as well as to operational problems and fields of application. The processes considered are briefly summarized as follows: ammonia air and steam stripping; ammonia vacuum distillation; ammonia precipitation as struvite; ammonia and nitrate removal by selected ion exchange; breakpoint chlorination; chloramine removal by selected activated carbon; ammonia adsorption on charcoal; chemical reduction of nitrate; advanced oxidation processes to convert ammonia and organic-N into nitrogen gas or nitrate. Special attention is given to advanced oxidation processes, as great research efforts are currently addressed to their implementation. These specifically include ozonation, peroxon oxidation, catalytic wet air oxidation, photo-catalytic oxidation and electrochemical oxidation.

  14. Radioimmunoassay determination of decreased amounts of. cap alpha. -L-fucosidase protein in fucosidosis

    Energy Technology Data Exchange (ETDEWEB)

    Andrews-Smith, G.L.; Alhadeff, J.A. (California Univ., San Diego, La Jolla (USA). Dept. of Neurosciences)

    1982-03-15

    Purified human liver ..cap alpha..-L-fucosidase (EC 3.2.1.51) has been radioiodinated by a chloramine-T procedure to a specific activity of 3.7 x 10/sup 6/ dpm/..mu..g protein without altering its apparent Michaelis constant for the 4-methylumbelliferyl substrate. This /sup 125/I-labeled ..cap alpha..-L-fucosidase has been used in development of a competitive binding radioimmunoassay for ..cap alpha..-L-fucosidase which can detect 1-2 ng of enzyme protein and has been employed to quantify the amount of ..cap alpha..-L-fucosidase protein in the liver and spleen from a patient with fucosidosis. Less than 1% of the normal amount of ..cap alpha..-L-fucosidase protein is present suggesting that normal amounts of catalytically inactive ..cap alpha..-L-fucosidase are not found in this disease.

  15. Fungicidal effect of 15 disinfectants against 24 fungal contaminants commonly found in bread and cheese manufacturing

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Kirsten; Nielsen, Per Væggemose

    1996-01-01

    Resistance of 19 mold- and 6 yeast- species against 15 commercial disinfectants was investigated by a suspension-method in which the fungicidal effect and germination time were determined at 20 °C. Disinfectants containing 0.5 % dodecyldiethylentriaminacetic acid, 10 g/l chloramine-T, 2.......0 % formaldehyde, 0.1 % potassium hydroxide, 3.0 % hydrogen peroxide or 0.3 % peracetic acid were ineffective as fungicides. The fungicidal effect of quaternary ammonium compounds and chlorine compounds showed great variance between species and among the 6 tested isolates of Penicillium roqueforti var. roqueforti...... with age. Both P. roqueforti var. roqueforti and E. repens showed great variability of resistance within isolates of each specie....

  16. Synthesis and evaluation of an (125)I-labeled azide prosthetic group for efficient and bioorthogonal radiolabeling of cyclooctyne-group containing molecules using copper-free click reaction.

    Science.gov (United States)

    Choi, Mi Hee; Shim, Ha Eun; Nam, You Ree; Kim, Hye Rim; Kang, Jung Ae; Lee, Dong-Eun; Park, Sang Hyun; Choi, Dae Seong; Jang, Beom-Su; Jeon, Jongho

    2016-02-01

    Herein we report the radiosynthesis of a pyridine derived azide prosthetic group for iodine radioisotope labeling of dibenzocyclooctyne (DBCO) conjugated molecules. The radiolabeling of the stannylated precursor 2 was conducted using [(125)I]NaI and chloramine-T to give (125)I-labeled azide ([(125)I]1) with high radiochemical yield (72±8%, n=4) and radiochemical purity (>99%). Using (125)I-labeled azide ([(125)I]1), cyclic RGD peptide and near infrared fluorescent molecule were efficiently labeled with modest to good radiochemical yields. The biodistribution study and SPECT/CT images showed that [(125)I]1 underwent rapid renal clearance. These results clearly demonstrated that [(125)I]1 could be used as an useful radiotracer for in vivo pre-targeted imaging as well as efficient in vitro radiolabeling of DBCO containing molecules. PMID:26748695

  17. Linking water treatment practices and fish welfare

    DEFF Research Database (Denmark)

    Zubiaurre, Claire; Pedersen, Lars-Flemming

    2016-01-01

    Peracetic acids can be used as sanitizers to control water quality in aquaculture systems. As an alternative to formalin, chloramine-T or copper sulphate, PAA has strong anti-microbial effects, degrades quickly and is relatively safe to use. Its mode of action and associated rapid decay can make....... Supportive enzymatic, biochemical and physiological biomarkers can be used along with gill and epidermal histological measures to evaluate the effects on water treatment regimens. The ultimate goal is to define the therapeutic window where fish welfare is not compromised.PAA is among the few disinfectants...... optimizing treatment protocols a challenge. Continuous low-dose applications seem to be a promising solution. In this preliminary study behavioral response was used to assess potential correlations with PAA dosage. A behavioral change or response is not necessarily an indication of compromised welfare...

  18. Development and Optimization of Sepharose Solid Phase Radioimmunoassay for Estimation of Thyroid Stimulating Hormone

    International Nuclear Information System (INIS)

    The aim of the present study was oriented to develop, optimize and validate solid phase radioimmunoassay, through many studies on Sepharose, for estimation of thyroid stimulating hormone in humane serum. Preparation of polyclonal antibodies was carried out in host rabbit animals against TSH antigen followed by partial purification of 1gG. Linkage of antibody 1gG to activated Sepharose CL-4B was carried out after activation of Sepharose with 1,1- carbonyldiimidazole. Labeling of TSH was carried out using chloramine-T as an oxidizing agent and the labeled tracer was purified through PD-10 column. Extensive studies were carried out to obtain the optimum conditions of using solid phase Sepharose to reach higher separation efficiency. The results of validation tests reveal that the local solid phase system is precise and accurate for evaluation of thyroid disorders

  19. Preparation and Validation of Double Antibody Radioimmunoassay for Thyroglobulin (Tg) using Balb/C Mice as Host Animals

    International Nuclear Information System (INIS)

    The preparation and development of primary reagents of thyroglobulin (Tg) radioimmunoassay technique with low cost is considered to be the main objective of present study. The production of polyclonal antibodies of thyroglobulin was undertaken by immunizing three bulb/C mice intraperitoneal through primary injection and two booster doses. The preparation of 125I-Tg radiotracer was carried out using chloramine-T as oxidizing agent. The preparation of thyroglobulin standards were carried out. Optimization and validation of the assay were studied out. The results obtained provide a highly sensitive, specific and accurate RIA system for thyroglobulin based on liquid phase separation. In conclusion, this assay could be used for diagnosis of thyroid cancer.

  20. Iodination of monoclonal antibodies, proteins and peptide using iodogen

    International Nuclear Information System (INIS)

    The use of the iodinating reagent 1,3,4,6-tetrachloro-3α, 6α-diphenylglycholuril (Iodogen) to label monoclonal antibodies (McAbs). Proteins and peptides was invesrigated with McAbs identified as mouse IgG and IgM, arginine-vasopressin (AVP), glucagon (Glu), human insulin(hI) and albumin(Alb). The labeled products were purified by gel chromatography and their immunoreactivity were detected by RIA or IRMA> Comparison of the Iodogen method with the lactoperoxides and chloramine-T methods showed that the Iodogen method had a number of advantages: 1) technically simpler ; 2) a high labeling efficiency could be obtained; 3) the immunoreactivity of the products was minimally affected; 4) the products were stable for up to 4 months

  1. Standardisation of radioimmunoassay for human insulin employing magnetizable cellulose particles

    International Nuclear Information System (INIS)

    We describe a convenient and flexible solid phase radioimmunoassay for human insulin employing magnetizable cellulose particles. Anti-porcine insulin antibody was covalently linked to magnetizable cellulose particles to form a stable and economical solid phase immunosorbent system. The tracer was prepared by radioiodinating insulin with 125I using Chloramine-T oxidation method. The analytical sensitivity of assay observed was 5.5 μIU/mL. Intra-assay and inter-assay variations were found to be <12 % along with analytical recovery of 93-109 %. The developed assay can be used for the routine analysis of clinical samples. In addition, concentration of the solid phase magnetizable immunosorbent can be easily varied as per the specific requirement for research purposes. (author)

  2. Measurement of plasma canine C peptide by radioimmunoassay

    International Nuclear Information System (INIS)

    A sensitive radioimmunoassay for canine C peptide (CCP) was established using synthetic CCP, a specific antiserum, and rabbit anti-guinea pig serum. Radioiodination was performed according to a modified chloramine T method. Tracer preparations have been used for 6 weeks after iodination. The standard curve ranges from 0.028 to 3.0 nmol/l. The intra-assay coefficient of variation (CV) was 3-5% and the inter-assay CV was 6-9% in the optimal range between 0.3 and 0.8 nmol/l. The average recovery of CCP added to plasma samples was 100.6% (n = 9). Canine insulin, porcine proinsulin, bovine proinsulin, and human C peptide exhibited no cross-reactivity. The mean fasting plasma CCP concentration was 0.089 +- 0.021 nmol/l in normal dogs and -0.005 +- 0.007 nmol/l (mean +- SEM) in diabetic dogs, respectively. (author)

  3. Fetal antigen 2: an amniotic protein identified as the aminopropeptide of the alpha 1 chain of human procollagen type I

    DEFF Research Database (Denmark)

    Teisner, B; Rasmussen, H B; Højrup, P;

    1992-01-01

    -PAGE analysis gave an M(r) = 27 kDa under reducing and non-reducing conditions for both forms, whereas the exact M(r) determined by mass spectrometry was 14,343 +/- 3 Da. FA2 was N-terminally blocked and after tryptic digestion the amino acid composition and sequences of the peptides showed identity...... with the aminopropeptide of the alpha 1 chain of human procollagen type I as determined by nucleotide sequences. After oxidative procedures normally employed for radio-iodination (iodogen and chloramine-T), FA2 lost its immunoreactivity. An antigen which cross-reacted with polyclonal rabbit anti-human FA2 was demonstrated...... in fetal calf serum. Gel filtration with analysis of fractions by inhibition ELISA showed that the bovine homologue was present in the same molecular forms as those in human amniotic fluid, and immunohistochemical analysis with anti-human FA2 showed that its distribution in bovine skin was identical...

  4. UP-REGULATION OF HEPATIC RECEPTOR FOR GROWTH HORMONE IN THE FLOUNDER (PARALICHTHYS OLIVACEUS) AFTER ORAL ADMINISTRATION WITH EXOGENOUS GH

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The iodination efficiency of salmon GH(Sgh) was 38.82%,using a modification of the chloramine-T method. The specific activity of the 125I-Sgh was about 40 μCi/μg protein. The results of binding assay showed a single class of high affinity and low-capacity binding site in flounder liver. Long-term administration with exogenous GH can induce the up-regulation of hepatic GH receptor in total binding capacity though there was no significant difference of association constant among any groups. Considering that there was no significant difference in capacity of free binding sites of livers from control and experimental fish, this result also indicated that the liver from experimental fish, compared to that from control fish, had more occupied binding sites.

  5. Preparation of [123I]- and [125I]epidepride: a dopamine D-2 receptor antagonist radioligand

    International Nuclear Information System (INIS)

    (S)-(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-[123I] iodo-2,3-dimethoxybenzamide (TDP 517) (proposed generic name, [123I]epidepride) is the iodine-123 substituted analogue of isoremoxipride (FLB 457), both of which are very potent dopamine D-2 antagonists (epidepride KD 0.024 nM). [123I] Epidepride was radioiodinated in 60-70% radiochemical yields in 35 min from the corresponding 5-(tributyltin) derivative using Na123I with a specific radioactivity of 3000 Ci/mmol, and oxidized in situ with chloramine-T. The aryltin precursor was prepared from non-labelled epidepride by palladium-catalyzed stannylation using bis(tri-n-butyltin) in triethylamine. Alternatively, using no carrier-added Na125I as the radioisotope, [125I] epidepride at 2000 Ci/mmol specific radioactivity was prepared in 86% radiochemical yield and 99% radiochemical purity after purification by reverse phase HPLC in ethanolic phosphate buffer. (author)

  6. UP-REGULATION OF HEPATIC RECEPTOR FOR GROWTH HORMONE IN THE FLOUNDER (PARALICHTHYS OLIVACEUS) AFTER ORAL ADMINISTRATION WITH EXOGENOUS GH

    Institute of Scientific and Technical Information of China (English)

    刘宗柱; 王金宝; 徐永立; 王勇; 张培军

    2001-01-01

    The iodination efficiency of salmon GH (sGH) was 38.82%,using a modification of the chloramine-T method. The specific activity of the 125I-sGH was about 40 μCi/μg protein. The results of binding assay showed a single class of high affinity and low-capacity binding site in flounder liver. Long-term administration with exogenous GH can induce the up-regulation of hepatic GH receptor in total binding capacity though there was no significant difference of association constant among any groups. Con-sidering that there was no significant difference in capacity of free binding sites of livers from control and experimental fish, this result also indicated that the liver from experimental fish, compared to that from control fish, had more occupied binding sites.

  7. Hypochlorite-induced damage to proteins

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    1998-01-01

    Stimulated monocytes and neutrophils generate hypochlorite (HOCl) via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl damages proteins by reaction with amino acid side-chains or backbone cleavage. Little information is available about the mechanisms and intermediates involved...... in these reactions. EPR spin trapping has been employed to identify radicals on proteins, peptides and amino acids after treatment with HOCl. Reaction with HOCl gives both high- and low-molecular-mass nitrogen-centred, protein-derived radicals; the yield of the latter increases with both higher HOCl:protein ratios...... and enzymic digestion. These radicals, which arise from lysine side-chain amino groups, react with ascorbate, glutathione and Trolox. Reaction of HOCl-treated proteins with excess methionine eliminates radical formation, which is consistent with lysine-derived chloramines (via homolysis of N-Cl bonds) being...

  8. 水处理组合消毒方式分析%Analysis of Combined Disinfectants in Water Treatment

    Institute of Scientific and Technical Information of China (English)

    黄旦光

    2012-01-01

    消毒的主要目的是为了灭活水中的致病微生物。水厂中主要被使用的消毒剂有氯、氯胺、臭氧、二氧化氯和紫外线。综合分析其消毒效巢和优缺点。重点介绍了多种组合消毒方式,以及分析其在水厂消毒中改善消毒效果和控制消毒副产物方面的应用。%The main objective of disinfecting is inactivating microorganism in water. The commonly used disinfectants in water treatment are chlorine, chloramines, chlorine dioxide, ozone, and UV. It is discussed about their advantages and disadvantages. It introduces some combined disinfectants and their special function on disinfecting improving and disinfection byproduct controlling.

  9. Kinetic Model for the Radical Degradation of Tri-Halonitromethane Disinfection Byproducts in Water

    Energy Technology Data Exchange (ETDEWEB)

    Stephen P. Mezyk; Bruce J. Mincher; William J. Cooper; S. Kirkham Cole; Robert V. Fox; Pieror R. Gardinali

    2012-10-01

    The halonitromethanes (HNMs) are byproducts of the ozonation and chlorine/chloramine treatment of drinking waters. Although typically occurring at low concentrations HNMs have high cytotoxicity and mutagenicity, and may therefore represent a significant human health hazard. In this study, we have investigated the radical based mineralization of fully-halogenated HNMs in water using the congeners bromodichloronitromethane and chlorodibromonitromethane. We have combined absolute reaction rate constants for their reactions with the hydroxyl radical and the hydrated electron as measured by electron pulse radiolysis and analytical measurements of stable product concentrations obtained by 60Co steady-state radiolysis with a kinetic computer model that includes water radiolysis reactions and halide/nitrogen oxide radical chemistry to fully elucidate the reaction pathways of these HNMs. These results are compared to our previous similar study of the fully chlorinated HNM chloropicrin. The full optimized computer model, suitable for predicting the behavior of this class of compounds in irradiated drinking water is provided.

  10. Kinetic model for the radical degradation of tri-halonitromethane disinfection byproducts in water

    Science.gov (United States)

    Mezyk, Stephen P.; Mincher, Bruce J.; Cooper, William J.; Kirkham Cole, S.; Fox, Robert V.; Gardinali, Piero R.

    2012-10-01

    The halonitromethanes (HNMs) are byproducts of the ozonation and chlorine/chloramine treatment of drinking waters. Although typically occurring at low concentrations HNMs have high cytotoxicity and mutagenicity, and may therefore represent a significant human health hazard. In this study, we have investigated the radical based mineralization of fully-halogenated HNMs in water using the congeners bromodichloronitromethane and chlorodibromonitromethane. We have combined absolute reaction rate constants for their reactions with the hydroxyl radical and the hydrated electron as measured by electron pulse radiolysis and analytical measurements of stable product concentrations obtained by 60Co steady-state radiolysis with a kinetic computer model that includes water radiolysis reactions and halide/nitrogen oxide radical chemistry to fully elucidate the reaction pathways of these HNMs. These results are compared to our previous similar study of the fully chlorinated HNM chloropicrin. The full optimized computer model, suitable for predicting the behavior of this class of compounds in irradiated drinking water, is provided.

  11. Receptor-purified, Bolton-Hunter radioiodinated, recombinant, human epidermal growth factor: An improved radioligand for receptor studies

    International Nuclear Information System (INIS)

    We report an assessment of the applicability of the Bolton-Hunter method to the radioiodination of epidermal growth factor (EGF). Recombinant human EGF (hEGF) could be radioiodinated successfully by this method, whereas murine EGF could not. Bolton-Hunter 125I-labeled hEGF was compared with commercial 125I-labeled hEGF prepared by the chloramine-T radioiodination method. Neither radioligand was sufficiently pure for a detailed characterization of the purportedly heterogeneous pattern of binding of EGF to its receptors. A procedure based on receptor adsorption was thus developed for repurification of the Bolton-Hunter 125I-labeled hEGF. This provided a much purer radioligand suitable for detailed studies of receptor-binding heterogeneity

  12. Drinking Water Disinfection by In-line Electrolysis: Product and Inorganic By-Product Formation

    Science.gov (United States)

    Bergmann, M. E. Henry

    This section covers peculiarities of so-called in-line electrolysis when drinking water is electrolysed to produce disinfection species killing microorganisms. Mainly mixed oxide electrodes (MIO) based on IrO2 and/or RuO2 coatings and boron-doped diamond electrodes were used in the studies. Artificial and real drinking water systems were electrolysed in continuous and discontinuous operating mode, varying water composition, current density and electrode materials. Results show, besides the ability of producing active chlorine, risks of inorganic disinfection by-products (DBPs) such as chlorate, perchlorate, nitrite, ammonium, chloramines, hydrogen peroxide and others. DBPs are responsible for analysis errors using DPD method for active chlorine measurements. Geometry may influence by-product yield. As a conclusion, the necessity of developing test routines for practical cell applications must be underlined.

  13. Selection and applicability of quenching agents for the analysis of polar iodinated disinfection byproducts.

    Science.gov (United States)

    Gong, Tingting; Tao, Yuxian; Xian, Qiming

    2016-11-01

    Iodide is widely present in drinking water sources as well as wastewater effluents. Chlorination and chloramination are the most commonly used disinfection methods. During chlorination or chloramination of drinking water/wastewater effluents, iodide may be oxidized to hypoiodous acid, which may further react with organic matter to form iodinated disinfection byproducts (DBPs). Recently, several new polar iodinated DBPs have been identified in drinking water as well as chlorinated wastewater effluents, and they have drawn increasing concerns due to their high toxicity. In DBPs studies, the selection of an appropriate quenching agent is critical to prevent further formation or any decomposition of DBPs during the holding time between sample collection and analysis. A previous study reported the applicability of different quenching agents for the analysis of various categories of chlorinated and brominated DBPs. But the applicability of quenching agents for the analysis of polar iodinated DBPs has not been reported. In this study, four different quenching agents (sodium sulfite, sodium thiosulfate, ascorbic acid and sodium borohydride) were tested for their suitability for the analysis of polar iodinated DBPs, and ascorbic acid was selected as the suitable quenching agent. Furthermore, it was found that ascorbic acid was applicable for the analysis of polar iodinated DBPs under the quenching agent doses of 0-0.42 mmol/L (stoichiometric amounts equivalent to 0-30 mg/L Cl2), contact times within 24 h, and pHs in the range of 6-8. Therefore, ascorbic acid was a widely applicable quenching agent for the analysis of polar iodinated DBPs under various conditions. PMID:27557432

  14. High-performance size exclusion chromatography with a multi-wavelength absorbance detector study on dissolved organic matter characterisation along a water distribution system.

    Science.gov (United States)

    Huang, Huiping; Sawade, Emma; Cook, David; Chow, Christopher W K; Drikas, Mary; Jin, Bo

    2016-06-01

    This study examined the associations between dissolved organic matter (DOM) characteristics and potential nitrification occurrence in the presence of chloramine along a drinking water distribution system. High-performance size exclusion chromatography (HPSEC) coupled with a multiple wavelength detector (200-280nm) was employed to characterise DOM by molecular weight distribution, bacterial activity was analysed using flow cytometry, and a package of simple analytical tools, such as dissolved organic carbon, absorbance at 254nm, nitrate, nitrite, ammonia and total disinfectant residual were also applied and their applicability to indicate water quality changes in distribution systems were also evaluated. Results showed that multi-wavelength HPSEC analysis was useful to provide information about DOM character while changes in molecule weight profiles at wavelengths less than 230nm were also able to be related to other water quality parameters. Correct selection of the UV wavelengths can be an important factor for providing appropriate indicators associated with different DOM compositions. DOM molecular weight in the range of 0.2-0.5kDa measured at 210nm correlated positively with oxidised nitrogen concentration (r=0.99), and the concentrations of active bacterial cells in the distribution system (r=0.85). Our study also showed that the changes of DOM character and bacterial cells were significant in those sampling points that had decreases in total disinfectant residual. HPSEC-UV measured at 210nm and flow cytometry can detect the changes of low molecular weight of DOM and bacterial levels, respectively, when nitrification occurred within the chloraminated distribution system. PMID:27266320

  15. Iodination of Fab fragments: Effect of I/Fab molar ratio

    Energy Technology Data Exchange (ETDEWEB)

    Kishore, R.; Eary, J.F.; Beaumier, P.L.; Hellstrom, K.E.; Hellstrom, I.; Nelp, W.B.

    1985-05-01

    Radioisotopes of iodine covalently coupled to antibodies have formed the standard against which other radiolabeled antibody tracers are compared. Since the use of monoclonal antibodies (MoAb) for the diagnosis and therapy of malignant diseases is increasing rapidly the authors wished to investigate radiolabeling variables which affect the immunointegrity of radioiodinated antibodies. The authors studied the electrophilic (chloramine-T) iodination of the Fab fragment of a murine MoAb against the high molecular weight proteoglycan antigen of human melanoma. The immunoreactivity of the iodianted Fab was assessed using a cell binding assay with formaldehyde-fixed cells of a selected cell line (number 2669). The in vitro stability of the labeled fragment was studied electrophoretically. The results indicate that the reaction time and concentrations of chloramine-T were not critical within broad limits. On the other hand immunoreactivity and deiodination over time (shelf-life) were inversely related and very sensitive to I/Fab molar ratio even at concentrations below -0.1 atom of I per Fab molecule. This has important implications for the radiotherapy of malignant tumors using I-131 labeled immunoglobulins which often have higher I/Fab molar ratios (100 mCi I-131/10 mg Fab approx. = 0.5 I atoms/Fab) versus diagnostic preparations (10 mCi I-131/5 mg Fab approx. = 0.1 I atoms/Fab). Thus the authors conclude that to maintain high immunointegrity the I/Fab molar ratio should be kept low, especially for therapeutic preparations, by using correspondingly higher amounts of Fab.

  16. Exercise but not mannitol provocation increases urinary Clara cell protein (CC16) in elite swimmers.

    Science.gov (United States)

    Romberg, Kerstin; Bjermer, Leif; Tufvesson, Ellen

    2011-01-01

    Elite swimmers have an increased risk of developing asthma, and exposure to chloramine is believed to be an important trigger factor. The aim of the present study was to explore pathophysiological mechanisms behind induced bronchoconstriction in swimmers exposed to chloramine, before and after swim exercise provocation as well as mannitol provocation. Urinary Clara cell protein (CC16) was used as a possible marker for epithelial stress. 101 elite aspiring swim athletes were investigated and urinary samples were collected before and 1 h after completed exercise and mannitol challenge. CC16, 11β-prostaglandin (PG)F(2α) and leukotriene E(4) (LTE(4)) were measured. Urinary levels of CC16 were clearly increased after exercise challenge, while no reaction was seen after mannitol challenge. Similar to CC16, the level of 11β-PGF(2α) was increased after exercise challenge, but not after mannitol challenge, while LTE(4) was reduced after exercise. There was no significant difference in urinary response between those with a negative compared to positive challenge, but a tendency of increased baseline levels of 11β-PGF(2α) and LTE(4) in individuals with a positive mannitol challenge. The uniform increase of CC16 after swim exercise indicates that CC16 is of importance in epithelial stress, and may as such be an important pathogenic factor behind asthma development in swimmers. The changes seen in urinary levels of 11β-PGF(2α) and LTE(4) indicate a pathophysiological role in both mannitol and exercise challenge. PMID:20696561

  17. N-Nitrosamines and halogenated disinfection byproducts in U.S. Full Advanced Treatment trains for potable reuse.

    Science.gov (United States)

    Zeng, Teng; Plewa, Michael J; Mitch, William A

    2016-09-15

    Water utilities are increasingly considering indirect and direct potable reuse of municipal wastewater effluents. Disinfection byproducts (DBPs), particularly N-nitrosamines, are key contaminants of potential health concern for potable reuse. This study quantified the concentrations of N-nitrosamines and a suite of regulated and unregulated halogenated DBPs across five U.S. potable reuse Full Advanced Treatment trains incorporating microfiltration, reverse osmosis, and UV-based advanced oxidation. Low μg/L concentrations of trihalomethanes, haloacetic acids, dichloroacetonitrile, and dichloroacetamide were detected in the secondary or tertiary wastewater effluents serving as influents to potable reuse treatment trains, while the concentrations of N-nitrosamines were more variable (e.g., N-nitrosodimethylamine). Ozonation promoted the formation of N-nitrosamines, haloacetaldehydes, and haloacetamides, but biological activated carbon effectively reduced concentrations of these DBPs. Application of chloramines upstream of microfiltration for biofouling control increased DBP concentrations to their highest levels observed along the treatment trains. Reverse osmosis rejected DBPs to varying degrees, ranging from low for some (e.g., N-nitrosamines, trihalomethanes, and haloacetonitriles) to high for other DBPs. UV-based advanced oxidation eliminated N-nitrosamines, but only partially removed halogenated DBPs. Chloramination of the treatment train product waters under simulated distribution system conditions formed additional DBPs, with concentrations often equaling or exceeding those in the treatment train influents. Overall, the concentration profiles of DBPs were fairly consistent within individual treatment trains for sampling campaigns separated by months and across different treatment trains for the same sampling time window. Weighting DBP concentrations by their toxic potencies highlighted the potential significance of haloacetonitriles, which were not effectively

  18. Bioanalytical assessment of the formation of disinfection byproducts in a drinking water treatment plant.

    Science.gov (United States)

    Neale, Peta A; Antony, Alice; Bartkow, Michael E; Farré, Maria José; Heitz, Anna; Kristiana, Ina; Tang, Janet Y M; Escher, Beate I

    2012-09-18

    Disinfection of drinking water is the most successful measure to reduce water-borne diseases and protect health. However, disinfection byproducts (DBPs) formed from the reaction of disinfectants such as chlorine and monochloramine with organic matter may cause bladder cancer and other adverse health effects. In this study the formation of DBPs through a full-scale water treatment plant serving a metropolitan area in Australia was assessed using in vitro bioanalytical tools, as well as through quantification of halogen-specific adsorbable organic halogens (AOXs), characterization of organic matter, and analytical quantification of selected regulated and emerging DBPs. The water treatment train consisted of coagulation, sand filtration, chlorination, addition of lime and fluoride, storage, and chloramination. Nonspecific toxicity peaked midway through the treatment train after the chlorination and storage steps. The dissolved organic matter concentration decreased after the coagulation step and then essentially remained constant during the treatment train. Concentrations of AOXs increased upon initial chlorination and continued to increase through the plant, probably due to increased chlorine contact time. Most of the quantified DBPs followed a trend similar to that of AOXs, with maximum concentrations observed in the final treated water after chloramination. The mostly chlorinated and brominated DBPs formed during treatment also caused reactive toxicity to increase after chlorination. Both genotoxicity with and without metabolic activation and the induction of the oxidative stress response pathway showed the same pattern as the nonspecific toxicity, with a maximum activity midway through the treatment train. Although measured effects cannot be directly translated to adverse health outcomes, this study demonstrates the applicability of bioanalytical tools to investigate DBP formation in a drinking water treatment plant, despite bioassays and sample preparation not

  19. Removal of cyclops in pre-oxidizing cooperation water treatment process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Zooplankton cyclops propagates profusely in waterbody, cannot be effectively inactivated by conventional disinfection process, and becomes a troublesome drinking water treatment problem. In this work, the qualitative and quantitative experimental studies were carried out on inactivation of zooplankton cyclops using oxidants, such as chlorine (Cl2), chlorine dioxide (ClO2), ozone (O3), hydrogen peroxide (H2O2), ozone/hydrogen peroxide (O3/H2O2), chloramines (Cl2-NH3) and potassium permanganate (KMnO4). The influences of various factors include different oxidant dosages, organic substance contents and pH values. The results showed that currently available oxidants used all might inactivate cyclops in some extent. According to the experimental results, chlorine dioxide, ozone, ozone/hydrogen peroxide and chloramines can be selected as effective oxidants for inactivating cyclops because of their strong inactivation abilities. Then the synergic removal effects on cyclops with ozone,ozone/hydrogen peroxide pre-oxidation followed by conventional water treatment processes were investigated. The results showed that ozone and ozone/hydrogen peroxide pre-oxidation can inactivate cyclops effectively, which then can be removed thoroughly by conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.65 mg/L of ozone and 6 mg/L of hydrogen peroxide, with the inactivation rate being 62% before conventional water treatment processes. Cyclops cannot appear in water after filtration with 1.8 mg/L of ozone, with the inactivation rate being 50% before conventional water treatment processes. For different oxidants, when removal rate was the best, the inactivation rate was not the same. These results may provide reference and model for actual waterworks.

  20. Kinetics of the oxidation of cylindrospermopsin and anatoxin-a with chlorine, monochloramine and permanganate.

    Science.gov (United States)

    Rodríguez, Eva; Sordo, Ana; Metcalf, James S; Acero, Juan L

    2007-05-01

    Cyanobacteria produce toxins that may contaminate drinking water sources. Among others, the presence of the alkaloid toxins cylindrospermopsin (CYN) and anatoxin-a (ANTX) constitutes a considerable threat to human health due to the acute and chronic toxicity of these compounds. In the present study, not previously reported second-order rate constants for the reactions of CYN and ANTX with chlorine and monochloramine and of CYN with potassium permanganate were determined and the influence of pH and temperature was established for the most reactive cases. It was found that the reactivity of CYN with chlorine presents a maximum at pH 7 (rate constant of 1265 M(-1)s(-1)). However, the oxidation of CYN with chloramine and permanganate are rather slow processes, with rate constants <1 M(-1)s(-1). The first chlorination product of CYN was found to be 5-chloro-CYN (5-Cl-CYN), which reacts with chlorine 10-20 times slower than the parent compound. The reactivity of ANTX with chlorine and chloramines is also very low (k<1M(-1)s(-1)). The elimination of CYN and ANTX in surface water was also investigated. A chlorine dose of 1.5 mg l(-1) was enough to oxidize CYN almost completely. However, 3 mg l(-1) of chlorine was able to remove only 8% of ANTX, leading to a total formation of trihalomethanes (TTHM) at a concentration of 150 microg l(-1). Therefore, chlorination is a feasible option for CYN degradation during oxidation and disinfection processes but not for ANTX removal. The permanganate dose required for CYN oxidation is very high and not applicable in waterworks.

  1. 组合氯化消毒工艺的卤代消毒副产物生成特性%Disinfection By-products Reduction of Combined Disinfection by Chlorine and Monochloramines in Distribution System

    Institute of Scientific and Technical Information of China (English)

    刘静; 陈超; 张晓健

    2009-01-01

    比较4种单独使用氯或组合氯化消毒工艺在较长管网停留时的卤代消毒副产物生成情况.4种工艺为单独游离氯消毒、氯胺消毒、清水池游离氯消毒后转氯胺的先氯后氨消毒、短时游离氯后转氯胺的顺序氯化消毒工艺.结果表明,游离氯消毒工艺在管网停留时间长时,卤代消毒副产物会持续大量的生成,而一氯胺消毒工艺生成的卤代消毒副产物量很低.目前使用较为普遍的先氯后氨消毒工艺与游离氯消毒相比,可以降低卤代消毒副产物的生成量,管网停留24 h时,三卤甲烷的生成量降低了9.6%,卤乙酸的生成量减低了42%.但是先氯后氨消毒工艺由于游离氯接触时间约为2 h,卤代消毒副产物已经大量生成.短时游离氯后转氯胺的顺序氯化消毒工艺,由于控制了游离氯的接触时间,可以在保障消毒工艺灭活微生物效果的同时更为有效地控制卤代消毒副产物,管网停留24 h时,三卤甲烷的生成量与单独游离氯消毒工艺相比降低了48%,卤乙酸的生成量减低了72%.因此,顺序氯化消毒工艺可以更好地控制卤代消毒副产物的生成,提高水质安全性.%Halogen disinfection by-products of four chlorined disinfection processes with long contact time in distribution system was compared in the work. These four disinfection processes are free chlorine, monochloramines, free chlorine disinfection in clearwelles while chloramines in distribution system, sequential chlorination disinfection with short-term free chlorine plus chloramines. According to the research, free chlorine generates most trihalomethanes(THMs) and haloacetic acids (HAAs) both in clearwells and distribution system, while monochloramines barely yield halogen DBPs. Free chlorine disinfection in clearwelles while chloramines in distribution system could reduce 9.6% of THMs and 42% of HAAs in 24 h contact time of distribution system compared with free chlorine. But free

  2. Generation of a high-valent iron imido corrolazine complex and NR group transfer reactivity.

    Science.gov (United States)

    Leeladee, Pannee; Jameson, Guy N L; Siegler, Maxime A; Kumar, Devesh; de Visser, Sam P; Goldberg, David P

    2013-04-15

    The generation of a new high-valent iron terminal imido complex prepared with a corrolazine macrocycle is reported. The reaction of [Fe(III)(TBP8Cz)] (TBP8Cz = octakis(4-tert-butylphenyl)corrolazinato) with the commercially available chloramine-T (Na(+)TsNCl(-)) leads to oxidative N-tosyl transfer to afford [Fe(IV)(TBP8Cz(+•))(NTs)] in dichloromethane/acetonitrile at room temperature. This complex was characterized by UV-vis, Mössbauer (δ = -0.05 mm s(-1), ΔE(Q) = 2.94 mm s(-1)), and EPR (X-band (15 K), g = 2.10, 2.00) spectroscopies, and together with reactivity patterns and DFT calculations has been established as an iron(IV) species antiferromagnetically coupled with a Cz-π-cation-radical (S(total) = 1/2 ground state). Reactivity studies with triphenylphosphine as substrate show that [Fe(IV)(TBP8Cz(+•))(NTs)] is an efficient NTs transfer agent, affording the phospharane product Ph3P═NTs under both stoichiometric and catalytic conditions. Kinetic analysis of this reaction supports a bimolecular NTs transfer mechanism with rate constant of 70(15) M(-1) s(-1). These data indicate that [Fe(IV)(TBP8Cz(+•))(NTs)] reacts about 100 times faster than analogous Mn terminal arylimido corrole analogues. It was found that two products crystallize from the same reaction mixture of Fe(III)(TBP8Cz) + chloramine-T + PPh3, [Fe(IV)(TBP8Cz)(NPPh3)] and [Fe(III)(TBP8Cz)(OPPh3)], which were definitively characterized by X-ray crystallography. The sequential production of Ph3P═NTs, Ph3P═NH, and Ph3P═O was observed by (31)P NMR spectroscopy and led to a proposed mechanism that accounts for all of the observed products. The latter Fe(III) complex was then rationally synthesized and structurally characterized from Fe(III)(TBP8Cz) and OPPh3, providing an important benchmark compound for spectroscopic studies. A combination of Mössbauer and EPR spectroscopies led to the characterization of both intermediate spin (S = 3/2 and low spin (S = 1/2) Fe(III) corrolazines, as

  3. Labeling of Octreotide With 131Ⅰ and Its Vitro Uptake in Inflammatory Cells for Graves' Ophthalmopathy%Octreotide的131I标记及Graves眼病炎症细胞的体外摄取

    Institute of Scientific and Technical Information of China (English)

    卢霞; 王荣福; 闫平; 周颖明; 张一帆

    2011-01-01

    将octreotide中的苯丙氨酸用酪氨酸替换合成[Tyr3]octreotide,对其进行了131I标记.考察了氯胺T标记法中氯胺T和[Tyr3]octreotide的用量对标记率的影响,观察了Graves眼病相关炎症细胞对131I-[Tyr3]octrotide的体外摄取情况.结果表明,对octreotide进行结构修饰后得到的[Tyr3]octreotide可以用于131I标记;氯胺T法对[Tyr3]octreotide进行131I标记时,氯胺T和[Tyr3]octreotide的最佳用量分别为1.6和1.4 μg,最高标记率为85%;T淋巴细胞、活化的成纤维细胞及血管内皮细胞均能够摄取131-[Tyr3]octreotide,而脂肪细胞的摄取则明显较少.以上结果表明,131I-[Tyr3]octreotide能够被Graves眼病发病过程中的炎症细胞摄取,具有用于Graves眼病发病过程中炎症反应程度评估的应用潜力.但由于摄取量还很小,需要进一步深入研究.%Phenylalanine was displaced by tyrosine in octreotide([Tyr3]octreotide) to study the labeling methods of [Tyr3]octreotide with 131Ⅰ, and the difference uptake ability of 131 Ⅰ-[Tyr3]octreotide in various cell lines of Graves ophthalmopathy were observed. The results showed that [Tyr3]octreotide could be labeled with 131Ⅰ by chloramines-T method and the optimal conditiona was 1.6μg chloramines-T and 1.4μg [Tyr3]octreotide. The labeling efficiency was 85%. T lymphocyte, fibroblast, and HUVEC could accumulate 131 Ⅰ-[Tyr3]octreotide largely compared to lipocyte, which indicated that 131Ⅰ-[Tyr3]octreotide could be combined with inflammatory cells in Graves' ophthalmopathy.

  4. 水中典型含氮有机物氯化生成消毒副产物的潜能研究%Chlorination Byproducts Formation Potentials of Typical Nitrogenous Organic Compounds in Water

    Institute of Scientific and Technical Information of China (English)

    徐倩; 徐斌; 覃操; 夏圣骥; 高乃云; 田富箱; 李大鹏

    2011-01-01

    选取了受污染原水中广泛存在的12种含氮有机物(除草剂、杀虫剂、氨基酸、工业品等),开展了氯化和氯胺化培养生成典型消毒副产物的实验,目的是通过对水中脲类除草剂、嗪类除草剂和其他含氮化合物培养生成不同消毒副产物的生成量,讨论不同种类含氮化合物生成含碳和含氮消毒副产物规律以及考察不同消毒副产物的可能前体物.研究发现,脲类除草剂经过量氯化和氯胺化可产生多达9种消毒副产物,反应活性最高的绿麦隆可生成三氯甲烷(CF)、一氯乙酸(MCAA)、二氯乙酸(DCAA)、1,1-二氯丙酮(1,1-DCP)、1,1,1-三氯丙酮%Twelve typical nitrogenous organic compounds including herbicides,pesticides,amino acids,industrial products etc in polluted raw water were selected to investigate formation of typical carbonaceous and nitrogenous DBPs during chlorination and chloramination.To indentify the formation mechanism of carbonaceous and nitrogenous disinfection byproducts from nitrogenous chemicals,chlorination and chloroamination of urea herbicides,triazine herbicides,amino acid,and other compounds were investigated.As a result,the potential precursors for different DBPs were defined as well.It has been identified that widely used urea herbicides could produce as many as 9 specific DBPs.The chlorotoluron shows highest reactivity and yields chloroform(CF),monochloroacetic acid(MCAA),dichloroacetic acid(DCAA),1,1-dichloro-acetone(1,1-DCP),1,1,1-trichloro-acetone(1,1,1-TCP),chloropicrin(NTCM),dichloro-acetonitrile(DCAN),dimethylnitrosamine(NDMA).The results indicated that aldicarb and dinoseb are important precursors of CF,DCAA,MCAA,NTCM as well.High concentrations of CF and DCAA were found during L-tryptophan chlorination.Furthermore,DBPs formation pathways and mechanisms were suggested during chlorination and chloramination of chlorotoluron,ametryn,dinoseb L-tryptophan.

  5. Labeling Lanreotide with 125I and 188Re. China

    International Nuclear Information System (INIS)

    Lanreotide (D-β-Nal-Cys-Try-D-Trp-Lys-Val-Cys-Thr-NH2) is a new somatostatin analogue. It can bind to human somatostatin receptor (hSSTR) subtype 2 through 5 with high affinity and to hSSTR subtype 1 with low affinity. We investigate labeling condition, quality control and stability in vitro of 125I-Lanreotide and 188Re-lanreotide respectively. (A) Lanreotide is labeled with 125I using Chloramine T. The effect of reaction condition (such as reaction time, pH value, Lanreotide amount, quantity of Chloramine T and reaction volume) on labeling yield is investigated in detail. (B) The labeling yield and radiochemical purity (RP) is measured with paper chromatography (PC) and Sep-Pak C18 Cartridge. For PC method, 125I-Lanreotide is spotted on the Whatman No.1 paper and developed in the mixture of CH3CH2CH2CH2OH and CH3CH2OH and NH4OH (v/v/v=5:2:1), the Rf value of every component in the mobile phase is given in table 1. For Sep-Pak C18 Cartridge methods each cartridge is washed with 10 ml of ethanol followed by 10 ml of iso-CH3CH2CH2OH solution. Aliquots of 0.1 mI sample is loaded onto the cartridge, unbound peptide (sodium iodine-125) is eluted with 5 ml of 0.5mol/L sodium acetate solution, 125I-Lanreotide is eluted with 5 mI of 95% aqueous ethanol solution. (C) The stability of 125I-Lanreotide in vitro is investigated by labeling compound incubating for 48 hours at 37 deg. C in the 0.9% sodium chloride solution and RP is tested by PC at specific time intervals. (D) Lanreotide is labeled directly with 188Re via the mixture of citrate and tartate using stannous chloride as reduced agent. The influence of reaction conditions such as pH, temperature, amount of stannous chloride, amount of Lanreotide and reaction time on labeling yield is investigated in detail. At the time, the stability in vitro quality control and animal test are evaluated

  6. Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment

    Institute of Scientific and Technical Information of China (English)

    Wang Leilei; Chen Wei; Lin Tao

    2008-01-01

    The quantitative change and size distribution of particles in the effluents from a sand filter and a granular activated carbon (GAC) filter in a drinking water treatment plant were investigated. The average total concentration of particles in the sand filter effluent during a filter cycle was 148 particles/mL, 27 of which were larger than 2 μm in size. The concentration in the GAC effluent (561 particles/mL) was significantly greater than that in the sand filter effluent. The concentration of particles larger than 2 μm in the GAC filter effluent reached 201 particles/mL, with the amount of particles with sizes between 2 μm and 15 μm increasing. The most probable number (MPN) of carbon fines reached 43 unit/L after six hours and fines between 0.45 μm and 8.0 μm accounted for more than 50%. The total concentration of outflowing bacteria in the GAC filter effluent, 350 CFU (colony-forming units) /mL, was greater than that in the sand filter effluent, 210 CFU/mL. The desorbed bacteria concentration reached an average of 310 CFU/mg fines. The disinfection efficiency of desorbed bacteria was lower than 40% with 1.5 mg/L of chlorine. The disinfection effect showed that the inactivation rate with 2.0 mg/L of chloramine (90%) was higher than that with chlorine (70%). Experimental results indicated that the high particle concentration in raw water and sedimentation effluent led to high levels of outflowing particles in the sand filter effluent. The activated carbon fines in the effluent accounted for a small proportion of the total particle amount, but the existing bacteria attached to carbon fines may influence the drinking water safety. The disinfection efficiency of desorbed bacteria was lower than that of free bacteria with chlorine, and the disinfection effect on bacteria attached to carbon fines with chloramine was better than that with only chlorine.

  7. Effects of UV irradiation and UV/chlorine co-exposure on natural organic matter in water

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei; Zhang, Zaili; Yang, Xin; Xu, Yiyue; Liang, Yongmei, E-mail: liangym@mail.sysu.edu.cn

    2012-01-01

    The effects of co-exposure to ultraviolet (UV) irradiation (with either low- or medium-pressure UV lamps) and free chlorine (chloramine) at practical relevant conditions on changes in natural organic matter (NOM) properties were investigated using four waters. The changes were characterized using the specific disinfection by-product formation potential (SDBPFP), specific total organic halogen formation potential (STOXFP), differential UV absorbance ( Increment UVA), and size-exclusion chromatography (SEC). The results for exposure to UV irradiation alone and for samples with no exposure were also obtained. The SDBPFPs in all UV-irradiated NOM waters observed were higher than those of non-irradiated samples. UV irradiation led to increases in STOXFPs as a result of chlorination, but no changes, or only small decreases, from chloramination. UV irradiation alone led to positive Increment UVA spectra of the four NOM waters; co-exposure to UV and chlorine gave larger negative Increment UVA spectra than those obtained by chlorine exposure alone. No obvious changes in SEC results were observed for samples only irradiated with UV light; co-exposure gave no detectable changes in the abundances of small fractions for exposure to chlorine only. Both UV photooxidation and photocatalytic oxidation appear to affect the reactivity of the NOM toward subsequent chlorination, and the magnitude of the changes is generally greater for medium-pressure lamps than for low-pressure lamps. These results suggest that applying UV disinfection technology to a particular source may not always be disinfection by-product-problem-free, and the interactions between UV light, chlorine, and NOM may need to be considered. - Highlights: Black-Right-Pointing-Pointer We discussed the effects of co-exposure to UV light and chlorine on properties of natural organic matters in waters. Black-Right-Pointing-Pointer UV irradiation led to increases in SDBPFP and STOXFP of NOM waters from chlorination. Black

  8. Halonitroalkanes, halonitriles, haloamides, and N-nitrosamines: a critical review of nitrogenous disinfection byproduct formation pathways.

    Science.gov (United States)

    Shah, Amisha D; Mitch, William A

    2012-01-01

    Interest in the formation of nitrogenous disinfection byproducts (N-DBPs) has increased because toxicological research has indicated that they are often more genotoxic, cytotoxic, or carcinogenic than many of the carbonaceous disinfection byproducts (C-DBPs) that have been a focus for previous research. Moreover, population growth has forced utilities to exploit source waters impaired by wastewater effluents or algal blooms. Both waters feature higher levels of organic nitrogen, that might serve as N-DBP precursors. Utilities are exploring new disinfectant combinations to reduce the formation of regulated trihalomethanes and haloacetic acids. As some of these new combinations may promote N-DBP formation, characterization of N-DBP formation pathways is needed. Formation pathways for halonitroalkanes, halonitriles, haloamides, and N-nitrosamines associated with chlorine, ozone, chlorine dioxide, UV, and chloramine disinfection are critically reviewed. Several important themes emerge from the review. First, the formation pathways of the N-DBP families are partially linked because most of the pathways involve similar amine precursors. Second, it is unlikely that a disinfection scheme that is free of byproduct formation will be discovered. Disinfectant combinations should be optimized to reduce the overall exposure to toxic byproducts. Third, the understanding of formation pathways should be employed to devise methods of applying disinfectants that minimize byproduct formation while accomplishing pathogen reduction goals. Fourth, the well-characterized nature of the monomers constituting the biopolymers that likely dominate the organic nitrogen precursor pool should be exploited to predict the formation of byproducts likely to form at high yields.

  9. Iodine-125 Chitosan-Vitamin C complex. Preparation, characterization and application

    Energy Technology Data Exchange (ETDEWEB)

    Elbarbary, Ahmed M. [National Center for Radiation Research and Technology, Cairo (Egypt). Polymer Chemistry Dept.; Shafik, H.M.; Ebeid, N.H.; Ayoub, S.M. [Atomic Energy Authority, Cairo (Egypt). Hot Lab. Center; Othman, Sameh H. [Atomic Energy Authority, Cairo (Egypt). Nuclear Research Center

    2015-07-01

    In heterogeneous conditions, water soluble Chitosan-Vitamin C Complex (CSVC) is successfully synthesized via the ionic interaction between γ-degraded CS and VC. Chitosan (CS) of low molecular weight (MW) is prepared using γ-irradiation method. The coupling of CS and vitamin C (VC) is carried out by the chemical treatment of VC with the γ-degraded CS. The formation of CSVC complex instead of physical mixture is confirmed by FT-IR and UV spectrometry. Characterization by transmission electron microscope (TEM) and dynamic light scattering (DLS) shows the formation of a nanostructure in 40 nm range. The preparation of labeled CSVC was performed using chloramines-T oxidation method. The labeling feasibility of CSVC nanostructure by Iodine-125 ({sup 125}I) is investigated. The optimized conditions of labeling are thought to be 50 μg of oxidizing agent, pH 3, and one minute reaction time. The Biodistribution activity of {sup 125}I radiolabeled CSVC nanostructure ({sup 125}I-CSVC) is examined on a group of different ascites tumor bearing mice. Calculation of the biodistribution percentages shows that the tumor, liver, and kidney are the targeting organs of {sup 125}I-CSVC nanostructure.

  10. Differential effects on innate versus adaptive immune responses by WF10.

    Science.gov (United States)

    Giese, Thomas; McGrath, Michael S; Stumm, Susanne; Schempp, Harald; Elstner, Erich; Meuer, Stefan C

    2004-06-01

    Oxidative compounds that are physiologically generated in vivo can induce natural defense mechanisms to enhance the elimination of pathogens and to limit inflammatory tissue damage in the course of inflammation. Here, we have investigated WF10, a chlorite-based non-toxic compound for its functional activities on human PBMC in vitro. WF10 exerts potent immune-modulatory effects through generating endogenous oxidative compounds such as taurine chloramine. Proliferation and IL-2 production of anti-CD3 stimulated PBMC were inhibited by WF10, as was the nuclear translocation of the transcription factor NFATc. In PBMC and monocytes, however, WF10 induced pro-inflammatory cytokines like IL-1beta, IL-8, and TNF-alpha. In the monocytic cell line THP-1, the activation of the transcription factors AP-1 and NFkappaB by WF10 was demonstrated. Inhibition of NFAT regulated genes in activated lymphocytes in concert with the induction of several myeloid cell associated pro-inflammatory genes in monocytes represents a novel mechanism of immune modulation.

  11. Preparation, purification and primary bioevaluation of radioiodinated ofloxacin. An imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Kandil, Shaban; Seddik, Usama; Hussien, Hiba; Shaltot, Mohamed [Atomic Energy Authority, Cairo (Egypt). Cyclotron Project; El-Tabl, Abdou [Monofia Univ. (Egypt). Faculty of Science

    2015-07-01

    The broad-spectrum antibiotic agents have been demonstrated as promising diagnostic tools for early detection of infectious lesions. We set out ofloxacin (Oflo), a second-generation fluoroquinolone, for the radioiodination process. In particular, this was carried out with {sup 125}I via an electrophilic substitution reaction. The radiochemical yield was influenced by different factors; drug concentration, different oxidizing agents, e.g. chloramine-T, iodogen and n-bromosuccinimide, pH of medium, reaction time, temperature and different organic media. These parameters were studied to optimize the best conditions for labeling with ofloxacin. We found that radiolabeling in ethanol medium showed a 70% radiochemical yield of {sup 125}I-ofloxacin. The radioiodination was determined by means of TLC and HPLC. The cold labeled Oflo ({sup 127}I-Oflo) was prepared and controlled by HPLC. The cold labeled Oflo was also confirmed by NMR and MS techniques. Furthermore, biodistribution studies for labeled {sup 125}I-Oflo were examined in two independent groups (3 mice in each one); control and E. Coli-injected (inflamed). The radiotracer showed a good localization in muscle of thigh for inflamed group as compared to control. In conclusion, ofloxacine might be a promising target as an anti-inflammatory imaging agent.

  12. Development of an 'In vitro' system for the caption essay of T3; Desarrollo de un sistema 'In vitro' para el ensayo de captacion de T3

    Energy Technology Data Exchange (ETDEWEB)

    Lavalley, C.; Ferro, G.; Zambrano, F.; Lezama, J

    1990-02-15

    Triiodothyronine uptake (T3U) is a qualitative technique for evaluation of the unsaturation capacity of thyroid binding globulin (TBG). This paper presents results related to a T3 standardized serum and the integration of T3-I-125, and adsorbent for labelled hormone. Labelled hormone were prepared by the chloramine T method and then purified by high performance liquid chromatography. The specific activity was 500 {mu} Ci/ {mu} g. Various adsorbents such as: Norit A Charcoal, calcium silicate, talc, bovine serum albumin macroaggregated (BSAM) were used in different buffers as: Tris-HCl, barbital and Michaelis. Standardized serum was prepared by mixing different euthyroid sera. Best conditions for T3U assays were achieved with 15 mg/ml. BSAM at pH 8.6 in presence of Tris-HCl buffer for hypothyroid and hyperthyroid sera, for which we obtained < 0.9 {+-} 0.04 and > 1.1 {+-} 0.05 respectively as a T3U index with a 3.0 % of coefficient variation. The reagents so prepared can be conveniently used for T3U assays. (Author)

  13. Sample Enrichment for Bioanalytical Assessment of Disinfected Drinking Water: Concentrating the Polar, the Volatiles, and the Unknowns.

    Science.gov (United States)

    Stalter, Daniel; Peters, Leon I; O'Malley, Elissa; Tang, Janet Yat-Man; Revalor, Marion; Farré, Maria José; Watson, Kalinda; von Gunten, Urs; Escher, Beate I

    2016-06-21

    Enrichment methods used in sample preparation for the bioanalytical assessment of disinfected drinking water result in the loss of volatile and hydrophilic disinfection byproducts (DBPs) and hence likely tend to underestimate biological effects. We developed and evaluated methods that are compatible with bioassays, for extracting nonvolatile and volatile DBPs from chlorinated and chloraminated drinking water to minimize the loss of analytes. For nonvolatile DBPs, solid-phase extraction (SPE) with TELOS ENV as solid phase performed superior compared to ten other sorbents. SPE yielded >70% recovery of nonpurgeable adsorbable organic halogens (AOX). For volatile DBPs, cryogenic vacuum distillation performed unsatisfactorily. Purge and cold-trap with crushed ice serving as condensation nuclei achieved recoveries of 50-100% for trihalomethanes and haloacetonitriles and approximately 60-90% for purged AOX from tap water. We compared the purgeable versus the nonpurgeable fraction by combining purge-and-trap extraction with SPE. The purgeable DBP fraction enriched with the purge-and-trap method exerted a lower oxidative stress response in mammalian cells than the nonpurgeable DBPs enriched with SPE after purging, while contributions of both fractions to bacterial cytotoxicity was more variable. 37 quantified DBPs explained almost the entire AOX in the purge-and-trap extracts, but <16% in the SPE extracts demonstrating that the nonpurgeable fraction is dominated by unknown DBPs. PMID:27153244

  14. Removal of the cyanotoxin anatoxin-a by drinking water treatment processes: a review.

    Science.gov (United States)

    Vlad, Silvia; Anderson, William B; Peldszus, Sigrid; Huck, Peter M

    2014-12-01

    Anatoxin-a (ANTX-a) is a potent alkaloid neurotoxin, produced by several species of cyanobacteria and detected throughout the world. The presence of cyanotoxins, including ANTX-a, in drinking water sources is a potential risk to public health. This article presents a thorough examination of the cumulative body of research on the use of drinking water treatment technologies for extracellular ANTX-a removal, focusing on providing an analysis of the specific operating parameters required for effective treatment and on compiling a series of best-practice recommendations for owners and operators of systems impacted by this cyanotoxin. Of the oxidants used in drinking water treatment, chlorine-based processes (chlorine, chloramines and chlorine dioxide) have been shown to be ineffective for ANTX-a treatment, while ozone, advanced oxidation processes and permanganate can be successful. High-pressure membrane filtration (nanofiltration and reverse osmosis) is likely effective, while adsorption and biofiltration may be effective but further investigation into the implementation of these processes is necessary. Given the lack of full-scale verification, a multiple-barrier approach is recommended, employing a combination of chemical and non-chemical processes.

  15. Radioimmunoassay of triiodothyronine in urine

    International Nuclear Information System (INIS)

    In 21 cases of hypothyroidism, in 39 cases of hyperthyroidism, in 54 healthy subjects, in 23 pregnant women, and in certain internal diseases determinations of triiodothyronine were carried out in urine by radioimmunoassay. Anti-T3 antibodies were obtained in rabbits and sheep immunized with a complex of bovine albumin with triiodothyronine ester. Labelled triiodothyronine of high specific activity was obtained by iodinating triodothyronine by the chloramine method. Determinations of triiodothyronine were performed in morning urine and the obtained values were calculated for one-hour excretion. In healthy subjects the excretion of T3 was from 20 to 95 ng/hour, in hyperthyroidism it was significantly raised to from 120 to over 600 ng/hour, while in most cases of hypothyroidism it was decreased. In pregnancy the urinary excretion of T3 was normal amounting to from 34 to 87 ng/hour, although in most cases the serum T3 concentration was raised. In cases of anorexia nervosa and in obese starving subjects the excretion of T3 fell significantly, and similarly low excretion was found in some cases of debilitating diseases and myocardial infarction. (author)

  16. Application of different /sup 125/I tracers in radioimmunoassays of estradiol-17. beta

    Energy Technology Data Exchange (ETDEWEB)

    Bienert, R.; Flentje, H.; Herzmann, H. (Akademie der Wissenschaften der DDR, Berlin-Buch. Zentralinstitut fuer Isotopen- und Strahlenforschung; Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung)

    1984-01-01

    Some different /sup 125/I-labelled estradiol tracers were produced by direct radioiodizing of estradiol and also of the histamine and tyramine conjugates of estradiol-3-carboxymethylether (E/sub 2/-3-CM) by means of the chloramine-T method. The linkage properties of these tracers were investigated in relation to the /sup 3/H-labelled estradiol opposite to the antisera, which were produced against the cow serum albumin (RSA) conjugates of E/sub 2/-3-CM and estradiol-6-carboxymethyloxime (E/sub 2/-6-CMO). As suitable system for the radioimmunological estradiol determination could be revealed 4-/sup 125/I-iodine estradiol in connection with one antiserum in each case of the radioligand antiserum combinations against E/sub 2/-3-CM-RSA- and E/sub 2/-6-CMO-RSA-conjugate. The double antibody method is used for separation in optimized RIA systems. The first and the second antibody reaction take place simultaneously.

  17. Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems.

    Science.gov (United States)

    Scott, Daniel B; Van Dyke, Michele I; Anderson, William B; Huck, Peter M

    2015-12-01

    The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence-absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems.

  18. Preparation of directly iodinated steroid hormones and related directly halogenated compounds

    International Nuclear Information System (INIS)

    The preparation of directly iodinated radioactive steroid hormones is described for use in radioimmunoassays or radiolocalization and treatment of human breast tumours. The radioactive iodinated steroid hormone is prepared by reacting a parent steroid hormone with an alkali metal iodide containing radioactive 123I, 125I, 130I or 131I in the presence of hydrogen peroxide or chloramine-T. The parent steroid hormones include the adrenal corticosteroids, the estrogens, the progestogens, the progestins and the diuretic and antidiuretic agents. The radioactive iodinated steroid hormone is prepared by iodinating the parent steroid hormone directly on the cyclopentanophenanthrene nucleus. The radioactive iodinated steroid hormones have the same antigenicity and receptor site specificity as the parent steroid hormone. The invention is illustrated by 1) the method of iodination of estradiol-17β, 2) results for the percentage labelling of several steroids and steroid hormones, 3) results for the radioimmunoassay of 125I-estradiol and 4) results for the binding of directly iodinated estradiol-17β in an estrogen receptor assay of human breast cancer. (U.K.)

  19. Biodistribution and radioimmunoimage of iodine-125 labeled anti-human ADAM15 polyclonal antibody in nude mice bearing human gastric carcinoma xenografts

    International Nuclear Information System (INIS)

    Objective: To investigate the biodistribution of Iodine-125 labeled anti-human ADAM15 polyclonal antibody in nude mice bearing human gastric carcinoma xenografts. Methods: The anti-human ADAM15 polyclonal antibody was labeled with I-125 using Chloramine-T method. The labeling efficiency and radiochemical purity of 125I-anti-ADAM15 antibody were measured. The SPECT planar imaging of nude mice bearing gastric carcinoma xenografts were performed at 1, 4, 8, 24, and 48 h post-injection and the biodistribution of 125I-anti-ADAM15 antibody was measured at 48 h after injection. Results: The labeling efficiency of 125I-anti-ADAM15 antibody was (75.16±9.43)% and its radiochemical purity was (99.44±0.21)% . Tumors could be cleanly visualized in SPECT planar images, and the radioactivity ratio of tumor to non-tumor tissue was 3.84±0.43 at 48 h post-injection. Conclusion: 125I-anti-ADAM15 antibody can target the gastric carcinoma in vivo, and provide good radioimmunoimages. (authors)

  20. Experimental research for tumor VIP receptor imaging

    International Nuclear Information System (INIS)

    To study the possibility of radioactive labelled vasoactive intestinal peptide (VIP) for tumor VIP receptor imaging. 125I-VIP was prepared by chloramine-T method, and purified by Sephadex G-50 column chromatography. The bioactivity and stability of 125I-VIP were measured by silica 60 F254 TLC and competition test to SGC7901 cell in vitro. The biodistribution of 125I-VIP was studied in the nude mice bearing tumor. The results showed that labelled rate of 125I was 73.8%, the specific activity was 18.2 PBq/mol, the radiochemical purity (RCP) was over 98% and remained 96.3% after 48 days stored at -80 degree C. The specific binding of 125I-VIP to the SGC7901 cell was inhibited by VIP in dose dependence in the competition experiment. The radioactivity of tumor was higher than that of muscles in all phases (P<0.05-0.01), the peak activity of tumor occurred at 30 min (3.58 +- 0.48ID%/g) and the peak ratio of T/N occurred at 60 min after the injection. The activity of lungs was obviously higher than that of blood, the intestine was always in low level. Most of the activity in the body was mainly eliminated from kidney. The present study demonstrated that the radioactive labelled VIP is a promising agent for tumor VIP receptor scintigraphy

  1. Disinfection by-product formation during seawater desalination: A review.

    Science.gov (United States)

    Kim, Daekyun; Amy, Gary L; Karanfil, Tanju

    2015-09-15

    Due to increased freshwater demand across the globe, seawater desalination has become the technology of choice in augmenting water supplies in many parts of the world. The use of chemical disinfection is necessary in desalination plants for pre-treatment to control both biofouling as well as the post-disinfection of desalinated water. Although chlorine is the most commonly used disinfectant in desalination plants, its reaction with organic matter produces various disinfection by-products (DBPs) (e.g., trihalomethanes [THMs], haloacetic acids [HAAs], and haloacetonitriles [HANs]), and some DBPs are regulated in many countries due to their potential risks to public health. To reduce the formation of chlorinated DBPs, alternative oxidants (disinfectants) such as chloramines, chlorine dioxide, and ozone can be considered, but they also produce other types of DBPs. In addition, due to high levels of bromide and iodide concentrations in seawater, highly cytotoxic and genotoxic DBP species (i.e., brominated and iodinated DBPs) may form in distribution systems, especially when desalinated water is blended with other source waters having higher levels of organic matter. This article reviews the knowledge accumulated in the last few decades on DBP formation during seawater desalination, and summarizes in detail, the occurrence of DBPs in various thermal and membrane plants involving different desalination processes. The review also identifies the current challenges and future research needs for controlling DBP formation in seawater desalination plants and to reduce the potential toxicity of desalinated water. PMID:26099832

  2. Production of antibodies against secretin and their use for radioimmunoassay of secretin

    International Nuclear Information System (INIS)

    Synthetic thyroglobulin was bonded to bovine albunia and thyroglobulin according to the principle of the carbodiimide condensation reaction. 16 rabbits were immunized with these conjugates and with unconjugated secretin. Secretin labelling with 125I was carried out by the chloramin-T method. The tracer has a specific activity of 15.45 mCi/mg. A secretin RIA was developed using the double antibody method. The sensitivity of the system could be raised by variation of the specific activity of the tracer and optimisation of the incubation parameters. Antisera were compared. The titers of secretin/bovine albumine conjugate antisera were similar to the antisera against secretin thyroglobulin conjugate. The sensitivity of the standard curves was higher for secretin/bovine albumin conjugate antisera than for thyroglobulin conjugate antisera. Two antisera were tested for specificity. The detection threshold of antiserum S 5 IX was 12,43 pmol/l while the 50% intercept was at 55.45 pmol/l. This antiserum is particularly suitable for a secretin RIA. (orig./MS)

  3. Disinfection byproduct formation from chlorination of pure bacterial cells and pipeline biofilms.

    Science.gov (United States)

    Wang, Jun-Jian; Liu, Xin; Ng, Tsz Wai; Xiao, Jie-Wen; Chow, Alex T; Wong, Po Keung

    2013-05-15

    Disinfection byproduct (DBP) formation is commonly attributed to the reaction between natural organic matters and disinfectants, yet few have considered the contribution from disinfecting bacterial materials - the essential process of water disinfection. Here, we explored the DBP formation from chlorination and chloramination of Escherichia coli and found that most selected DBPs were detectable, including trihalomethanes, haloacetonitriles, chloral hydrate, chloropicrin, and 1,1,1-trichloro-2-propanone. A positive correlation (P = 0.08-0.09) between DBP formation and the log reduction of E. coli implied that breaking down of bacterial cells released precursors for DBP formation. As Pseudomonas aeruginosa is a dominant bacterial species in pipeline biofilms, the DBP formation potentials (DBPFPs) from its planktonic cells and biofilms were characterized. Planktonic cells formed 7-11 times greater trihalomethanes per carbon of those from biofilms but significantly lower (P disinfection of bacterial planktonic cells in source water and ex situ reaction between biofilms and residual chlorine in pipeline networks as hitherto unknown DBP sources in drinking water.

  4. Preparation of 125I-labeled human growth hormone of high quality binding properties endowed with long-term stability

    International Nuclear Information System (INIS)

    125I-labeled human growth hormone (125I-labeled.hGH) was prepared by using two variants of the chloramine T labelling procedure and purified by polyacrylamide gel electrophoresis (PAGE) of the reaction mixture. Variant A produced a tracer with high specific activity (100 +/- 10 microCi/microgram), high maximal binding capacity to antibodies (93%) and long-term stability (at least 150 days at -20/degree/C). No diiodinated tyrosil residues could be detected in this tracer. Variant B was devised to obtain higher yields of labeled hormone. The electrophoresis of the iodination mixture revealed two radioactive components with Rm values of 0.49 and 0.55 which result from the iodination of hGH variants preexisting in the starting material. Both tracers had similar specific activities (70 +/- 10 microCi/microgram), high maximal binding capacity to antibodies or receptors (80-100%, after 80 days of their obtention) and high stability (at least 100 days at -20/degree/C). It is concluded that the iododerivatives of hGH obtained by either method are adequate to perform radioimmunoassay and receptor studies and have long-term stability

  5. Factors Affecting Bacterial Growth in Drinking Water Distribution System

    Institute of Scientific and Technical Information of China (English)

    WEI LU; XIAO-JIAN ZHANG

    2005-01-01

    Objective To define the influence of some parameters, including assimilable organic carbon (AOC), chloramine residual, etc. on the bacterial growth in drinking water distribution systems. Methods Three typical water treatment plants in a northern city (City T) of China and their corresponding distribution systems were investigated. Some parameters of the water samples, such as heterotrophic plate content (HPC), AOC, CODMn, TOC, and phosphate were measured. Results The AOC in most water samples were more than 100 μg/L, or even more than 200 μg/L in some cases. The HPC in distribution systems increased significantly with the decrease of residual chlorine. When the residual chlorine was less than 0.1 mg/L, the magnitude order of HPC was 104 CFU/mL; when it was 0.5-0.7 mg/L, the HPC was about 500 CFU/mL. Conclusion For controlling the biostability of drinking water, the controlling of AOC and residual chlorine should be considered simultaneously. The influence of phosphors on the AOC tests of water is not significant. Phosphors may not be the limiting nutrient in the water distribution systems.

  6. Iodine-123 labeled derivatives of methylphenidate: potential SPECT radiopharmaceuticals for brain dopamine transporters

    International Nuclear Information System (INIS)

    Since dl-threo-[11C]methylphenidate (Ritalin) and especially the more active enantiomer, d-threo-[11C]methylphenidate, have favorable properties for PET studies, we prepared two radioiodinated analogs of methylphenidate, p-[123I]iodomethylphenidate and m-[123I]iodo-p-hydroxymethylphenidate with a view to evaluating them as potential SPECT tracers. To prepare p-[123I]iodomethylphenidate, the p-tributyltin derivative was prepared from the previously reported p-bromomethylphenidate and reacted under acidic conditions with I-123 iodide plus chloramine-T at room temperature for 90 seconds. The predomimant radioactive product was obtained in 85% radiochemical yield and > 10 Ci/μmol specific radioactivity after HPLC purification. It had the same HPLC retention time as a spectroscopically characterized non-radioactive p-iodomethylphenidate standard prepared via nitration of methylphenidate and diazotization, after protection of the secondary amino group by benzoylation. A second radioiodinated methylphenidate derivative, m-[123)I]iodop-hydroxymethylphenidate was prepared in 80% radiochemical yield by direct iodination of the known p-hydroxymethylphenidate. In this case the non-radioactive standard was prepared by iodination of p-hydroxyritalinic acid using I2 and iodic acid, followed by esterification. (author)

  7. Role of taurine in the pathogenesis of obesity.

    Science.gov (United States)

    Murakami, Shigeru

    2015-07-01

    Taurine is a sulfur-containing amino acid that is present in mammalian tissues in millimolar concentrations. Taurine is involved in a diverse array of biological and physiological functions, including bile salt conjugation, osmoregulation, membrane stabilization, calcium modulation, anti-oxidation, and immunomodulation. The prevalence of obesity and being overweight continues to rise worldwide at an alarming rate. Obesity is associated with a higher risk of metabolic and cardiovascular diseases, cancer, and other clinical conditions. Ingestion of taurine has been shown to alleviate metabolic diseases such as hyperlipidemia, diabetes, hypertension, and obesity in animal models. A global epidemiological survey showed that 24-h urinary taurine excretion, as a marker of dietary taurine intake, was inversely associated with BMI, blood pressure, and plasma cholesterol in humans. In addition, taurine chloramine, an endogenous product derived from activated neutrophils, has been reported to suppress obesity-induced oxidative stress and inflammation in adipocytes. Synthetic activity and concentration of taurine in adipose tissues and plasma have been shown to decrease in humans and animals during the development of obesity, suggesting a relationship between taurine deficiency and obesity. In this review, I summarize the effects of taurine on the progression of obesity in animal models and humans. Furthermore, I discuss possible mechanisms underlying the antiobesity effects of taurine.

  8. Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants

    Institute of Scientific and Technical Information of China (English)

    SHAO Jiahui; FANG Xuliang; HE Yiliang; JIN Qiang

    2008-01-01

    Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditionalchlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaksin the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose.Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditionson the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration,liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9%was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically foundto be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammoniaremoval rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plantmembrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatmentplant, also paved the way towards a larger scale application.

  9. Nitrogen origins and the role of ozonation in the formation of haloacetonitriles and halonitromethanes in chlorine water treatment.

    Science.gov (United States)

    Yang, Xin; Shang, Chii; Shen, Qianqian; Chen, Baiyang; Westerhoff, Paul; Peng, Jinfeng; Guo, Wanhong

    2012-12-01

    Nitrogenous disinfection byproducts (N-DBPs) such as haloacetonitriles (HANs) and halonitromethanes (HNMs) are formed during water chlorination. Preozonation is sometimes applied to control trihalomethane (THM) formation, but this may risk promoting the formation of HNMs and HANs. The role of ozone in the formation of HANs and HNMs in natural waters remains unclear. The nitrogen sources involved in HAN and HNM formation during the chloramination of dissolved organic matter (DOM) with and without preozonation were evaluated using (15)N-labeled monochloramine. The origin of the nitrogen involved in HAN formation was found to depend on the ratio of dissolved organic carbon to nitrogen. In nitrogen-rich solutions HAN nitrogen was mainly from DOM constituents. The formation of (15)N-labeled dichloroacetontrile (DCAN) accounted for approximately 30% of the DCAN produced from all hydrophilic acidic and neutral isolates, which have low carbon to nitrogen ratios, while it reached over 50% for the hydrophobic acidic, basic, and neutral isolates with high carbon to nitrogen ratios. Unlabeled trichloronitromethane (TCNM) accounted for over 90% of the total TCNM produced from most of the isolates. The remaining less than 10% of the TCNM was probably generated through an aldehyde pathway. Preozonation reduced DCAN but enhanced the yield of TCNM. The destruction of amino acids and amine structures and subsequent formation of nitro groups by preozonation may help explain the reduced DCAN and increased TCNM formation. PMID:23153098

  10. Comparison of fipronil sources in North Carolina surface water and identification of a novel fipronil transformation product in recycled wastewater.

    Science.gov (United States)

    McMahen, Rebecca L; Strynar, Mark J; McMillan, Larry; DeRose, Eugene; Lindstrom, Andrew B

    2016-11-01

    Fipronil is a phenylpyrazole insecticide that is widely used in residential and agricultural settings to control ants, roaches, termites, and other pests. Fipronil and its transformation products have been found in a variety of environmental matrices, but the source[s] which makes the greatest contribution to fipronil in surface water has yet to be determined. A sampling effort designed to prioritize known fipronil inputs (golf courses, residential areas, biosolids application sites and wastewater facilities) was conducted in North Carolina to learn more about the origins of fipronil in surface water. High resolution mass spectrometry (HRMS) analysis indicated that fipronil and its known derivatives were routinely present in all samples, but concentrations were substantially elevated near wastewater treatment plant outfalls (range 10-500ng/L combined), suggesting that they predominate as environmental sources. Corresponding recycled wastewater samples, which were treated with NaOCl for disinfection, showed disappearance of fipronil and all known degradates. HRMS and nuclear magnetic resonance (NMR) analysis techniques were used to determine that all fipronil-related compounds are oxidized to a previously unidentified fipronil sulfone chloramine species in recycled wastewater. The implications of the presence of a new fipronil-related compound in recycled wastewater need to be considered. PMID:27378152

  11. Iodine-125 Chitosan-Vitamin C complex. Preparation, characterization and application

    International Nuclear Information System (INIS)

    In heterogeneous conditions, water soluble Chitosan-Vitamin C Complex (CSVC) is successfully synthesized via the ionic interaction between γ-degraded CS and VC. Chitosan (CS) of low molecular weight (MW) is prepared using γ-irradiation method. The coupling of CS and vitamin C (VC) is carried out by the chemical treatment of VC with the γ-degraded CS. The formation of CSVC complex instead of physical mixture is confirmed by FT-IR and UV spectrometry. Characterization by transmission electron microscope (TEM) and dynamic light scattering (DLS) shows the formation of a nanostructure in 40 nm range. The preparation of labeled CSVC was performed using chloramines-T oxidation method. The labeling feasibility of CSVC nanostructure by Iodine-125 (125I) is investigated. The optimized conditions of labeling are thought to be 50 μg of oxidizing agent, pH 3, and one minute reaction time. The Biodistribution activity of 125I radiolabeled CSVC nanostructure (125I-CSVC) is examined on a group of different ascites tumor bearing mice. Calculation of the biodistribution percentages shows that the tumor, liver, and kidney are the targeting organs of 125I-CSVC nanostructure.

  12. Identification of nitrosamine precursors from urban drainage during storm events: A case study in southern China.

    Science.gov (United States)

    Bei, Er; Liao, Xiaobin; Meng, Xiangting; Li, Shixiang; Wang, Jun; Sheng, Deyang; Chao, Meng; Chen, Zhuohua; Zhang, Xiaojian; Chen, Chao

    2016-10-01

    The drinking water sources of many cities in southern China are frequently contaminated by upstream urban drainage during storm events, which brings high concentrations of N-nitrosamine (NA) precursors and poses a threat to the safety of drinking water. We conducted two sampling campaigns during the heavy rain season in 2015 in one representative city in southern China. We detected that the concentration of N-nitrosodimethylamine formation potential (NDMA FP) in urban drainage during two storm events was 80-115 ng/L and the total formation potential concentration of nine nitrosamines (TNA9 FP) was 145-165 ng/L. To address the deteriorated water quality, 30 mg/L of powdered activated carbon (PAC) was fed into the water intake. PAC adsorption alone could remove 52% of NDMA FP and 52% of TNA FP, while the subsequent conventional process only removed 8% of TNA FP. We isolated six chemicals (N,N-benzyldimethylamine, 5-[(dimethylamino)methyl]-2-furanmethanol, N,N-dimethyl-3-aminophenol, N,N-dimethylethylamine, Ziram, and N,N-dimethylaniline) and confirmed them to be NA precursors. Among these NA precursors, Ziram was identified for the first time as a NA precursor that is formed via chloramination; its molar yield for NDMA was 6.73 ± 0.40%. PMID:27393968

  13. Effect of bipolar electrode material on the reclamation of urban wastewater by an integrated electrodisinfection/electrocoagulation process.

    Science.gov (United States)

    Llanos, Javier; Cotillas, Salvador; Cañizares, Pablo; Rodrigo, Manuel A

    2014-04-15

    This work presents an integrated electrodisinfection/electrocoagulation (ED-EC) process for urban wastewater reuse that employs iron bipolar electrodes. Boron doped diamond (BDD) was used as the anode and stainless steel (SS) as the cathode. A perforated iron plate was introduced between the anode and cathode to function as a bipolar electrode. This ED-EC combined cell makes it possible to conduct the simultaneous removal of microbiological content and elimination of turbidity from urban wastewater. The results show that current densities greater than or equal to 6.70 A m(-2) enable complete disinfection of the effluent and the removal of more than 90% of its initial turbidity. Hypochlorite and chloramines formed during the ED-EC process were found to be the main compounds responsible for the disinfection process. Furthermore, a cell configuration of cathode (inlet)-anode (outlet) improves the process performance by enhancing turbidity removal. Finally, the influence of the bipolar electrode material (iron or aluminium) was assessed. The results indicate that the efficiency of the electrodisinfection process depends mainly on the anodic material and is not influenced by the material of the bipolar electrode. In contrast, the removal of turbidity is more efficient when using iron as a bipolar electrode, especially at low current densities, due to the formation of a passive layer on the aluminium that hinders the dissolution of the bipolar electrode. PMID:24531029

  14. Development and clinical application of human gastrin radioimmunoassay

    International Nuclear Information System (INIS)

    The determination of human gastrin levels in the blood is very important for diagnosis of gastrointestinal disorders. This work describes the radioimmunoassay of gastrin developed according to Russell et al. and its clinical application measuring fasting levels of this hormone in normal subjects, gastrectomized, chagasics, patients with chronic renal failure (CRF), pernicious anemia (PA) and Zollinger-Ellison syndrome (ZES). Synthetic human gastrin was used for radioiodination and as standard, while the specific antibody was raised in rabbits. Gastrin was radioiodinated by a modification of the chloramine T technique and purified by anion exchange chromatography in QAE-Sephadex A-25 to a specific activity around 200 uCi/ug. The assays were performed by incubation of 125I-gastrin, standard gastrin (zero to 500 pmol/l) or unknown samples with the antiserum for 4 days at 40C. The antibody bound and free 125 I-gastrin was separated by adsorption of the latter to the charcoal. The basal gastrin values of normal subjects ranged from 2 to 74 pmol/l, being these levels higher in the chagasics (from 6 to 261 pmol/l). Higher levels of gastrin were determined in patients with CRF (from 12 to 350 pmol/l), PA (from 160 to 680 pmol/l) and with ZES(1010 pmol/l), while very low levels were confirmed in gastrectomized (from 1 to 8 pmol/l). (author)

  15. Comparison of three radioligands, selenium-75, iodine-125, and tritium, in the radioimmunoassay of methotrexate

    International Nuclear Information System (INIS)

    Radioimmunoassays for methotrexate are described, involving use of a rabbit antiserum to a conjugate of the drug and bovine serum albumin and the drug labeled with tritium, selenium-75, or iodine-125. Of the two gamma emitters, the 75Se-labeled drug was prepared by the Radiochemical Centre, Amersham, England and the 125I-labeled drug in the laboratory, by the Chloramine T iodination technique. The stability of labels with both methods allows use of the faster, cheaper, and simpler gamma-counting techniques, with results available after 3 h. All three methods have acceptable sensitivity, accuracy, precision, and reproducibility, and are specific for methotrexate, with no significant interference from naturally occurring folates or leucovorin. The assays in which the gamma emitters are used have significant practical advantages over the beta emitter and are much better suited to automation and clinical application. The main advantage of 75Se-labeled methotrexate is its longer half-life, 121 days, as compared with 60 days for 125I

  16. Development of Solid Phase Radioimmunoassay for Measuring Methotrexate and 7-Hydroxy Methotrexate in Biological Fluids using Magnetizable Particles

    International Nuclear Information System (INIS)

    The objective of the present study was to prepare a solid phase magnetic particles radioimmunoassay (RIA) reagents. Development as well as optimization and validation of RIA system for the assessment of methotrexate (MTX) and its main metabolite 7-hydroxy methotrexate (7-OH MTX) in human serum were described. Preparation of 125 I-MTX and 125 I -7(OH) MTX were carried out using tyrosine methyl ester (TME) and chloramine-T (Ch-T) as oxidizing agent. HPLC column was used for purification of the prepared tracers. The production of polyclonal anti - bodies was carried out using six rabbits divided to two groups. The first one was immunized intraperitoneal through primary injection and three booster doses using MTX-BSA conjugate while the other group was immunized using 7(OH) MTX-BSA conjugate. Low density magnitizable cellulose iron oxide particles have been used to couple covalently to polyclonal antibody. The results obtained provide a low cost, simple, sensitive, specific, and accurate RIA system based on magnetizable solid phase separation.

  17. Spectrophotometric Determination of Trace Cyanide in Fruit Wines by the Catalytic Reaction of Ninhydrin Following Micro-Distillation

    Directory of Open Access Journals (Sweden)

    Saksit Chanthai

    2014-03-01

    Full Text Available Trace analysis of cyanide (CN based on the absorbance of the catalytic reaction of ninhydrin (NH in the presence of CN- was developed. This reaction was investigated consisting of 0.08 M NH, 0.4 M Na2CO3, 1% (v/v Tween 20 and 2.5 M NaOH in 5-mL final volume. The absorbance of the CN-NH complex was measured against the reagent blank at 598 nm. The calibration curve was widely linear over the range of 40-160 µg/L with r2 >0.99. The method recoveries of free cyanide, bound cyanide and total cyanide for wine samples were found in the range of 76.2-89.2%, 73.2-91.2% and 76.8-94.8%, respectively, at 250 µg/L CN- spiked level. Limit of detection was 6 µg/L. The reproducibility of the proposed method was less than 4.44%. This method was then applied for local Thai fruit wines. No trace amount of cyanide was detected, as if high recovery (88.4% of the micro-distillation was guaranteed. The obtained results were in agreement with those of the chloramine-T/barbituric acid-pyridine method with no statistically significant difference at 95% confidence level.

  18. Solid phase group specific absorbants in assays for glycoproteins

    International Nuclear Information System (INIS)

    The focus of this paper is on several technical advances in the assays for glycoprotein hormones and enzymes that have been achieved by use of the solid phase carbohydrate specific adsorbant concanavalin-A. Puriffication of glycoprotein radioligand after labelling by the chloramine-T method is readily accomplished using a small column of agarose bound concanavalin-A which separates glycoprotein radioligand from radioiodide and radiolabelled unadsorbed contaminants. After concanavalin-A column chromatography, radiolabelled glycoprotein hormone preparations exhibited improved binding to antibodies and tissue receptors. To increase the effective sensitivity of radioimmunoassays for glycoproteins, agarose bound concanavalin-A is used to extract and concentrate the glycoproteins from various biologic samples. For example, the effective sensitivity for the detection of human thyrotropin in serum was improved approximately 5 fold by using concanavalin-A concentrates of 1.5 ml of serum. Partial purification of the glycoprotein dopamine-β-hydroxylase from serum using agarose bound concanavalin-A resulted in separation of the serum factors that interfere with the measurement of enzyme activity. We conclude that in assays for glycoproteins, concanavalin-A is useful for purification of radioligand, for preparation of concentrates of glycoproteins from biologic samples, and for separation of glycoproteins from various interfering factors contained in biologic samples prior to radioligand or radioenzyme assay. (orig.)

  19. Solid-phase group-specific adsorbants in assays for glycoproteins

    International Nuclear Information System (INIS)

    The focus of the paper is on several technical advances in the assays for glycoprotein hormones and enzymes that have been achieved by the use of the solid-phase cabohydrate-specific adsorbant concanavalin-A. Purification of glycoprotein radioligand after labelling by the Chloramine-T method is readily accomplished using a small column of agarose-bound concanavalin-A which separates glycoprotein radioligand from radioiodide and radiolabelled unadsorbed contaminants. After concanavalin-A column chromatography, radiolabelled glycoprotein hormone preparations exhibited improved binding to antibodies and tissue receptors. To increase the effective sensitivity of radioimmunoassays for glycoproteins, agarose-bound concanavalin-A is used to extract and concentrate the glycoproteins from various biological samples. For example, the effective sensitivity for the detection of human thyrotropin in serum was improved approximately 5-fold by using concanavalin-A concentrates of 1.5ml of serum. Partial purification of the glycoprotein dopamine-β-hydroxylase from serum using agarose-bound concanavalin-A resulted in separation of the serum factors that interfere with the measurement of enzyme activity. We conclude that in assays for glycoproteins, concanavalin-A is useful for purification of radioligand, for preparation of concentrates of glycoproteins from biological samples and for separation of glycoproteins from various interfering factors contained in biological samples before radioligand or radioenzyme assay. (author)

  20. 125I Labelling of Protein Using Immobilized Enzyme

    International Nuclear Information System (INIS)

    For an effective solid-phase labelling of protein with 125I, studies on the immobilization of lactoperoxidase (LPO) on the inner wall of polystyrene tubes were carried out. Labelling of bovine serum albumin (BSA) and insulin was also practiced using the LPO immobilized tubes. The immobilized enzyme of about 2.5 μ g/tube was sufficient for small scale labelling since the results of radio-paper chromatography of the labelling mixture of insulin indicated that the yields were sufficiently high (80%) even in the reactions conducted at room temperature for 60 sec. The results of the Sephadex column chromatography indicated that the labelled products were not contaminated with LPO-125I, and the radiochemical purity of the products was more than 90%. In considering the general trend that the 125I labelled protein obtained by using LPO maintains its intactness better than those obtained by using chloramine-T, together with the tendency of yield enhancing with increase of reactants-concentration, the LPO immobilized tube method is estimated to be one of the simple methods of labelling. The product might be applicable without further purification.

  1. Asthma is more prevalent in elite swimming adolescents despite better mental and physical health.

    Science.gov (United States)

    Romberg, K; Tufvesson, E; Bjermer, L

    2012-06-01

    An increased risk of developing asthma has been reported among swimmers exposed to chloramine in pool arenas. The aim of the present study was to compare the prevalence of asthma and respiratory symptoms among elite aspiring swimmers compared with age-matched controls with different degrees of physical activity. We also aimed to relate these findings to mental and psychosocial factors. One hundred and one elite swimmers and 1628 age-matched controls answered a questionnaire containing questions about respiratory symptoms, lifestyle factors, mental and physical well-being. The controls were divided into three different groups according to the degree of physical activity, no physical activity, recreational training and elite training. Swimmers reported significantly more asthma symptoms, with 36.6% having physician-diagnosed asthma, compared with 16.2% among the controls. Use of regular medication was more common (14.9% vs 8.0%) and more swimmers reported an exacerbation of their asthma during the previous 12 months (16.8%) vs (5.8%) for the controls. Despite an increased prevalence of asthma symptoms, the swimmers reported best physical performance and best mental and physical well-being. They also had a healthier lifestyle without smoking and low alcohol consumption. PMID:20807384

  2. Improvement of labeling efficiency of glycoprotein-liposome conjugates with iodine-125 by using Bolton-Hunter Reagent and their distribution in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kawakita, Yasunori; Kojima, Shuji [Science Univ. of Tokyo, Noda, Chiba (Japan). Research Institute for Biological Sciences; Yamazaki, Noboru

    2000-07-01

    We have developed a new type of glycoprotein-liposome conjugates and examined their potential utilities as drug-targeting carriers which exploit cellular functions of carbohydrate-binding proteins, i.e. animal lectins. An extremely low labeling efficiency, however, has been often a big problem in biodistribution study by using radiolabeled glycoprotein-liposome conjugates. In this study, improvement of the labeling efficiency was conducted by using Bolton-Hunter Reagent (BHR). First, tyrosyl groups were introduced into liposome membrane through amines of a constitutive phospholipid, dipalmitoylphosphatidlethanolamine (DPPE). Then, glycoprotein-tyrosyl group introduced liposomes were iodinated with {sup 125}I according to Chloramine-T methods. Labeling efficiency was markedly elevated in comparison with the BHR-untreated liposome conjugates. There was no significant changes in binding activity of BHR-treated glycoprotein-liposome conjugates with lectin. However, biodistribution of glycoprotein-tyrosyl group introduced liposomes in mice was significantly different from the mother conjugates. Thus, another suitable method for radioiodination of the glycoprotein-liposome conjugates should be developed. (author)

  3. [Update of DIN 19.643--treatment and disinfection of swimming pool and bathing tub water].

    Science.gov (United States)

    Hässelbarth, U

    1992-08-01

    German Standards Specification DIN 19,643 is at present under revision for health reasons and because of both negative and positive experiences gathered in practice. To enable adaptation of the standards specification to future developments, a Part I of the specification is being created comprising the demands to be made on the quality of the water and general demands on the construction and operation of swimming pools and tubs and basins in bath houses, e.g. in spas or municipal swimming pools. The subsequent parts of the new specification (Part 2 to Part n) concern the demands to be made on individual combinations of processes; these can be supplemented at any time in accordance with technical progress without requiring revision of the entire standards specification. Essential innovations are the reformulation of the required efficiency of disinfection, the introduction of the parameters Legionella pneumophila, trihalogen methane (THM) and the reduction of the limit value for chloramines. Technically speaking, the new features concern the automatic measurement of the auxiliary parameters of hygiene such as redox potential, pH value and free chlorine, automatic control of disinfectant additions, automatic filter rinsing with fluidization of the filter-bed to a prescribed minimum bed expansion, and the sight-glas at the filter container. The demands made on Jacuzzi and warm water spouted bed besins are integrated into the specification, thus obviating the need for German Standards Specification DIN 19,644. PMID:1392275

  4. Chemiluminescent method for detection of eutrophication sources by estimation of organic amino nitrogen and ammonium in water.

    Science.gov (United States)

    Meseguer-Lloret, S; Molins-Legua, C; Verdú-Andrés, J; Campíns-Falcó, P

    2006-11-01

    An automatic method has been developed for the estimation of organic amino nitrogen (CH2-NH) and ammonium in water samples. We propose a continuous flow system in which nitrogen compounds react with hypochlorite reagent to produce chloramines. Subsequently, the mixture is mixed with luminol, generating a chemiluminescence signal. The signal emission at 425 nm, registered as a function of time, decreases as nitrogen concentration increases, due to the decrease on hypochlorite concentration. A large number of nitrogen compounds have been assayed and their sensitivities compared, in milligrams per liter nitrogen. The ammonium calibration graph, expressed as N, can be used for most of the assayed compounds. The linear interval was 0.24-4 mg L(-1) N, with the detection limit 0.07 mg L(-1) N. The chemiluminescence method was applied to the analysis of several kinds of real water samples, natural, lake, irrigation ditch, fountain, residual, and seawater in order to detect possible sources of eutrophication. The accuracy (% relative error) and precision were satisfactory, with mean values of 5 +/- 4 and 3 +/- 2, respectively. This procedure has been used to estimate nitrogen content in samples before and after Kjeldahl treatment. In the same samples, the N found for the untreated samples provided a good estimation of the N Kjeldahl. Sixty samples per hour can be analyzed, and the procedure can also be used for in situ monitoring.

  5. Factors affecting catalysis of copper corrosion products in NDMA formation from DMA in simulated premise plumbing.

    Science.gov (United States)

    Zhang, Hong; Andrews, Susan A

    2013-11-01

    This study investigated the effects of corrosion products of copper, a metal commonly employed in household plumbing systems, on N-nitrosodimethylamine (NDMA) formation from a known NDMA precursor, dimethylamine (DMA). Copper-catalyzed NDMA formation increased with increasing copper concentrations, DMA concentrations, alkalinity and hardness, but decreased with increasing natural organic matter (NOM) concentration. pH influenced the speciation of chloramine and the interactions of copper with DMA. The transformation of monochloramine (NH2Cl) to dichloramine and complexation of copper with DMA were involved in elevating the formation of NDMA by copper at pH 7.0. The inhibiting effect of NOM on copper catalysis was attributed to the rapid consumption of NH2Cl by NOM and/or the competitive complexation of NOM with copper to limit the formation of DMA-copper complexes. Hardness ions, as represented by Ca(2+), also competed with copper for binding sites on NOM, thereby weakening the inhibitory effect of NOM on NDMA formation. Common copper corrosion products also participated in these reactions but in different ways. Aqueous copper released from malachite [Cu2CO3(OH)2] was shown to promote NDMA formation while NDMA formation decreased in the presence of CuO, most likely due to the adsorption of DMA.

  6. Occurrence of carboxylic acids in different steps of two drinking-water treatment plants using different disinfectants.

    Science.gov (United States)

    Jurado-Sánchez, Beatriz; Ballesteros, Evaristo; Gallego, Mercedes

    2014-03-15

    The occurrence of 35 aliphatic and aromatic carboxylic acids within two full scale drinking-water treatment plants was evaluated for the first time in this research. At the intake of each plant (raw water), the occurrence of carboxylic acids varied according to the quality of the water source although in both cases 13 acids were detected at average concentrations of 6.9 and 4.7 μg/L (in winter). In the following steps in each treatment plant, the concentration patterns of these compounds differed depending on the type of disinfectant applied. Thus, after disinfection by chloramination, the levels of the acids remained almost constant (average concentration, 6.3 μg/L) and four new acids were formed (butyric, 2-methylbutyric, 3-hydroxybenzoic and 2-nitrobenzoic) at low levels (1.1-5 μg/L). When ozonation/chlorination was used, the total concentration of the carboxylic acids in the raw water sample (4.7 μg/L) increased up to 6 times (average concentration, 26.3 μg/L) after disinfection and 6 new acids (mainly aromatic) were produced at high levels (3.5-100 μg/L). Seasonal variations of the carboxylic acids under study showed that in both plants, maximum levels of all the analytes were reached in the coldest months (autumn and winter), aromatic acids only being found in those seasons.

  7. Clinical scale preparation and evaluation of {sup 131}I-Rituximab for Non-Hodgkin's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Kameswaran, Mythili; Vimalnath, K. Viswanathan; Rajeswari, Ardhi; Joshi, Prahlad Vasudeo; Samuel, Grace [Bhabha Atomic Research Centre, Mumbai (India). Radiopharmaceuticals Div.; Sarma, H.D. [Bhabha Atomic Research Centre, Mumbai (India). Radiation Biology and Health Sciences Div.

    2014-09-01

    Radioimmunotherapy (RIT) with anti CD20 MoAb conjugated to a β{sup -} emitting radioisotope like {sup 131}I or {sup 90}Y has the added advantage of delivering radiation not only to tumor cells that bind the antibody but also due to a crossfire effect, to neighboring tumor cells inaccessible to the antibody. In order to make available an indigenous radioimmunotherapeutic agent for Non Hodgkin's Lymphoma (NHL), radioiodinated Rituximab has been prepared and evaluated at a clinical scale. Radioiodination of Rituximab was performed by the conventional Chloramine T method using 7.4 GBq Na{sup 131}I in a lead shielded plant. Six batches of radioiodination were prepared and characterized by electrophoresis and HPLC to evaluate the reproducibility of the product. The product remained stable retaining the radiochemical purity > 95% upto 5 days after radioiodination. In vitro cell binding studies and biodistribution studies in normal Swiss mice have indicated the potential of this molecule as a radioimmunotherapeutic agent for NHL. (orig.)

  8. Powerful colloidal silver nanoparticles for the prevention of gastrointestinal bacterial infections

    Science.gov (United States)

    Le, Anh-Tuan; Tam Le, Thi; Quy Nguyen, Van; Hoang Tran, Huy; Dang, Duc Anh; Tran, Quang Huy; Vu, Dinh Lam

    2012-12-01

    In this work we have demonstrated a powerful disinfectant ability of colloidal silver nanoparticles (NPs) for the prevention of gastrointestinal bacterial infections. The silver NPs colloid was synthesized by a UV-enhanced chemical precipitation. Two gastrointestinal bacterial strains of Escherichia coli (ATCC 43888-O157:k-:H7) and Vibrio cholerae (O1) were used to verify the antibacterial activity of the as-prepared silver NPs colloid by means of surface disinfection assay in agar plates and turbidity assay in liquid media. Transmission electron microscopy was also employed to analyze the ultrastructural changes of bacterial cells caused by silver NPs. Noticeably, our silver NPs colloid displayed a highly effective bactericidal effect against two tested gastrointestinal bacterial strains at a silver concentration as low as ∼3 mg l‑1. More importantly, the silver NPs colloid showed an enhancement of antibacterial activity and long-lasting disinfectant effect as compared to conventional chloramin B (5%) disinfection agent. These advantages of the as-prepared colloidal silver NPs make them very promising for environmental treatments contaminated with gastrointestinal bacteria and other infectious pathogens. Moreover, the powerful disinfectant activity of silver-containing materials can also help in controlling and preventing further outbreak of diseases.

  9. Effect of oxidant exposure on the release of intracellular microcystin, MIB, and geosmin from three cyanobacteria species.

    Science.gov (United States)

    Wert, Eric C; Korak, Julie A; Trenholm, Rebecca A; Rosario-Ortiz, Fernando L

    2014-04-01

    The release of intracellular microcystin-LR (MC-LR), 2-methylisoborneol (MIB), and geosmin was investigated after the oxidation of three cyanobacteria (Microcystis aeruginosa (MA), Oscillatoria sp. (OSC), and Lyngbya sp. (LYN)). During the oxidation of 200,000 cells/mL of MA, release of intracellular MC-LR exceeded the World Health Organization (WHO) guideline of 1 μg/L during the lowest oxidant exposures (CT) tested: ozone (0 mg-min/L, below the ozone demand), chlorine (geosmin exceeded reported threshold odor values after exposure to chlorine, chlorine dioxide, and chloramine, which have low reactivity with these taste and odor compounds. Ozone oxidation of OSC yielded an increase in MIB concentration at lower exposures (≤2.9 mg-min/L), likely due to insufficient oxidation by hydroxyl radicals. The release of intracellular organic matter (IOM) was also measured to determine the potential of bulk measurements to act as a surrogate for cyanotoxins and metabolite release. In all cases, the dissolved organic carbon (DOC) release was less than 0.25 mgC/L, which lacked the sensitivity to indicate the release of MC-LR, MIB, or geosmin. The fluorescence index proved to be a more sensitive indicator of intracellular organic matter release than DOC for MA. These results illustrate that toxic or odorous compounds may be released from cyanobacteria cells during oxidation processes with minimal changes in the DOC concentration.

  10. The transport of humic and fulvic acids through sand

    International Nuclear Information System (INIS)

    The objective of this work was to produce stable iodine-125 labelled humic and fulvic acids for use in field tests at the BGS borehole array at Drigg in Cumbria. The first part of the report describes iodine-125 labelling of humic and fulvic acids by oxidation of iodide-125 by chloramine-T. Although the apparent efficiency of labelling was high, some of the iodinated humic dissociated on standing and during passage through sand columns. The second part of the report describes the production of a more stable iodinated humic and fulvic acid. This was achieved by adding reducing agent to the reaction mixture after iodination of the humic material. The addition of reducing agent decreased the apparent labelling efficiency of the humic materials but increased the stability. The third part of the report describes the preparation of iodinated-fulvic acid for use in a field test. Gel column separation showed that 95% of the activity was bound to fulvic acid on the day of the field experiment. Samples of this material were passed through 55 cm long sand columns. I-125 breakthrough occurred simultaneously with tritium but a proportion remained on the column. This sorbed, or deposited, material then eluted very slowly from the column. (author)

  11. A radioimmunoassay of chicken growth hormone using growth hormone produced by recombinant DNA technology: validation and observations of plasma hormone variations in genetically fat and lean chickens

    International Nuclear Information System (INIS)

    A radioimmunoassay (RIA) of chicken growth hormone (c-GH) has been developed using growth hormone produced by recombinant DNA technology. The best rabbit antiserum was used at 1/300,000 final dilution. Hormone labelling by iodine-125, achieved by chloramine T, allowed a specific activity of 3.7 MBq/μg. The equilibrium curves show that optimal conditions of incubation were reached at room temperature for 24h. This RIA used a second sheep antibody which precipitated the whole c-GH bound to the first antibody in the presence of polyethylene glycol solution (6%) at room temperature for 30 min. In our conditions, sensitivity was about 30 pg of c-GH per tube. Coefficient of variation was around 10%. No cross reaction was found with avian LH and prolactin. Thyrotrophin-releasing hormone (TRH) injection to young chickens induced 20-fold higher plasma c-GH concentrations. Simultaneous injection of somatostatin and TRH slightly reduced these concentrations. Hypoglycemia induced by insulin led to a drop of the plasma c-GH concentration. Conversely, refeeding or glucose load induced slight increases of the c-GH level. Genetically fat chickens tended to exhibit higher plasma c-GH concentrations than lean chickens

  12. Human C-peptide. Pt. 1

    International Nuclear Information System (INIS)

    Synthetic human C-peptide bearing a tyrosine group at its amino end is labelled with 125iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results of the two methods are compared. Antiserum to synthetic human C-peptide (without tyrosine), which was partially coupled to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pips concerning antibody production. The so-called 'hook effect' phenomenon is observed when setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated using the anion exchange resin amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum. (orig.)

  13. Measurement of insulin in human sera using a new RIA kit. 1

    International Nuclear Information System (INIS)

    A sensitive and versatile radioimmunoassay (RIA) for insulin was established using human insulin standard, a specific guinea pig anti-insulin antiserum and rabbit anti-guinea pig serum. Radioiodination was performed according to a modified chloramine T method. Tracer preparations were used for as long as 6 weeks after iodination. The standard curve ranges from 0.044 to 1.2 nmol/l. The intra-assay coefficient of variation (CV) was 3-5% and the inter-assay CV was 6-9% in the optimal range between 0.4 and 0.9 nmol/l. The average recovery of human insulin added to plasma or serum samples was 100.2 ± 2.0% (n = 38) and 100.1 ± 1.9% (n = 42), respectively. In addition to human insulin, procine, canine, rabbit and bovine insulin can also be determined but not rat or mouse insulin. The cross-reactivity of the antiserum with porcine proinsulin was found to be 40 % on the molar basis. The range of mean fasting plasma insulin concentrations in healthy subjects and under various pathological conditions were estimated. (author)

  14. Composition of cross-linked 125I-follitropin-receptor complexes

    International Nuclear Information System (INIS)

    Both of the alpha and beta subunits of intact human follitropin (FSH) were radioiodinated with 125I-sodium iodide and chloramine-T and could be resolved on sodium dodecyl sulfate-polyacrylamide gels. Radioiodinated FSH was affinity-cross-linked with a cleavable (nondisulfide) homobifunctional reagent to its membrane receptor on the porcine granulosa cell surface as well as to a Triton X-100-solubilized form of the receptor. Cross-linked samples revealed three additional bands of slower electrophoretic mobility, corresponding to 65, 83, and 117 kDa, in addition to the hormone bands. The hormone alpha beta dimer band corresponded to 43 kDa. Formation of the three bands requires the 125I-hormone to bind specifically to the receptor with subsequent cross-linking. Binding was prevented by an excess of the native hormone but not by other hormones. A monofunctional analog of the cross-linking reagent failed to produce the three bands. Reagent concentration-dependent cross-linking revealed that their formation was sequential; smaller complexes formed first and then larger ones. When gels of cross-linked complexes were treated to cleave covalent cross-links and then electrophoresed in a second dimension, 18-, 22-, and 34-kDa components were released, in addition to the alpha and beta subunits of the hormone

  15. Oxidative radioiodination damage to human lactoferrin

    International Nuclear Information System (INIS)

    Oxidative iodination of human lactoferrin (Lf) commonly performed by using the chloramine-T, the Iodogen or the lactoperoxidase method produces an unreliable tracer protein because of excessive and heterogeneous polymer formation. Before iodination a minor tetramer fraction may be demonstrable in iron-saturated Lf only. 125I-Lf polymers are mainly covalently linked, as suggested by the lack of substantial dissociation in SDS/polyacrylamide-gel electrophoresis. Damage to the 125I-Lf monomer may be another consequence of oxidative iodination. This is demonstrated in SDS/polyacrylamide-gel electrophoresis where 50% of the radioactivity of apparently normal monomer (Msub(r) 75000) is displaced to a lower-Msub(r) region (30000-67000) after reduction with dithiothreitol. Non-oxidative iodination by the Bolton-Hunter technique produces an antigenetically stable tracer that is not being subjected to polymerization and monomer degradation as judged by high performance gel chromatography and SDS/polyacrylamide-gel electrophoresis with and without dithiothreitol treatment. It is concluded that oxidation in itself leads to covalent non-disulphide cross-linking between human Lf molecules and, possibly, to intramolecular peptide-bond breaking becoming unmasked under reducing conditions. (author)

  16. Selective reactivity of monochloramine with extracellular matrix components affects the disinfection of biofilm and detached clusters.

    Science.gov (United States)

    Xue, Zheng; Lee, Woo Hyoung; Coburn, Kimberly M; Seo, Youngwoo

    2014-04-01

    The efficiency of monochloramine disinfection was dependent on the quantity and composition of extracellular polymeric substances (EPS) in biofilms, as monochloramine has a selective reactivity with proteins over polysaccharides. Biofilms with protein-based (Pseudomonas putida) and polysaccharide based EPS (Pseudomonas aeruginosa), as well as biofilms with varied amount of polysaccharide EPS (wild-type and mutant P. aeruginosa), were compared. The different reactivity of EPS components with monochloramine influenced disinfectant penetration, biofilm inactivation, as well as the viability of detached clusters. Monochloramine transport profiling measured by a chloramine-sensitive microelectrode revealed a broader diffusion boundary layer between bulk and biofilm surface in the P. putida biofilm compared to those of P. aeruginosa biofilms. The reaction with proteins in P. putida EPS multiplied both the time and the monochloramine mass required to achieve a full biofilm penetration. Cell viability in biofilms was also spatially influenced by monochloramine diffusion and reaction within biofilms, showing a lower survival in the surface section and a higher persistence in the middle section of the P. putida biofilm compared to the P. aeruginosa biofilms. While polysaccharide EPS promoted biofilm cell viability by obstructing monochloramine reactive sites on bacterial cells, protein EPS hindered monochloramine penetration by reacting with monochloramine and reduced its concentration within biofilms. Furthermore, the persistence of bacterial cells detached from biofilm (over 70% for P. putida and ∼40% for polysaccharide producing P. aeruginosa) suggested that currently recommended monochloramine residual levels may underestimate the risk of water quality deterioration caused by biofilm detachment.

  17. Antiseptics and microcosm biofilm formation on titanium surfaces

    Directory of Open Access Journals (Sweden)

    Georgia VERARDI

    2016-01-01

    Full Text Available Abstract Oral rehabilitation with osseointegrated implants is a way to restore esthetics and masticatory function in edentulous patients, but bacterial colonization around the implants may lead to mucositis or peri-implantitis and consequent implant loss. Peri-implantitis is the main complication of oral rehabilitation with dental implants and, therefore, it is necessary to take into account the potential effects of antiseptics such as chlorhexidine (CHX, chloramine T (CHT, triclosan (TRI, and essential oils (EO on bacterial adhesion and on biofilm formation. To assess the action of these substances, we used the microcosm technique, in which the oral environment and periodontal conditions are simulated in vitro on titanium discs with different surface treatments (smooth surface - SS, acid-etched smooth surface - AESS, sand-blasted surface - SBS, and sand-blasted and acid-etched surface - SBAES. Roughness measurements yielded the following results: SS: 0.47 µm, AESS: 0.43 µm, SB: 0.79 µm, and SBAES: 0.72 µm. There was statistical difference only between SBS and AESS. There was no statistical difference among antiseptic treatments. However, EO and CHT showed lower bacterial counts compared with the saline solution treatment (control group. Thus, the current gold standard (CHX did not outperform CHT and EO, which were efficient in reducing the biofilm biomass compared with saline solution.

  18. The contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using diamond anodes.

    Science.gov (United States)

    Bensalah, Nasr; Dbira, Sondos; Bedoui, Ahmed

    2016-07-01

    In this work, the contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using boron-doped diamond (BDD) anodes was investigated in different electrolytes. A complete mineralization of cyanuric acid was obtained in NaCl; however lower degrees of mineralization of 70% and 40% were obtained in Na2SO4 and NaClO4, respectively. This can be explained by the nature of the oxidants electrogenerated in each electrolyte. It is clear that the contribution of active chlorine (Cl2, HClO, ClO(-)) electrogenerated from oxidation of chlorides on BDD is much more important in the electrolytic degradation of cyanuric acid than the persulfate and hydroxyl radicals produced by electro-oxidation of sulfate and water on BDD anodes. This could be explained by the high affinity of active chlorine towards nitrogen compounds. No organic intermediates were detected during the electrolytic degradation of cyanuric acid in any the electrolytes, which can be explained by their immediate depletion by hydroxyl radicals produced on the BDD surface. Nitrates and ammonium were the final products of electrolytic degradation of cyanuric acid on BDD anodes in all electrolytes. In addition, small amounts of chloramines were formed in the chloride medium. Low current density (≤10mA/cm(2)) and neutral medium (pH in the range 6-9) should be used for high efficiency electrolytic degradation and negligible formation of hazardous chlorate and perchlorate. PMID:27372125

  19. Luminal oxidants selectively modulate electrogenic ion transport in rat colon

    Institute of Scientific and Technical Information of China (English)

    Julio M Mayol; Yolanda Adame-Navarrete; Pilar Alarma-Estrany; Elena Molina-Roldan; Fernando Huete-Toral; Jesus A Fernandez-Represa

    2006-01-01

    AIM: To investigate the effects of luminal exposure to H2O2 and two related thiol oxidizing agents on basal and stimulated chloride secretion in native colon using electrophysiological and pharmacological approaches.METHODS: Unstripped rat distal colon segments were mounted in Ussing chambers. Potential difference, cal culated resistance and short-circuit current across unstripped colon segments were monitored with a dual voltage/current clamp. Paracellular permeability was assessed by measuring the mucosa-to-serosa flux of a fluorescent probe (FITC).RESULTS: Luminal exposure to hydrogen peroxide transitorily stimulated chloride secretion without altering barrier function. This stimulatory effect could be blocked by basolateral atropine but not indomethacin. The cysteine and methionine oxidizing compounds, phenylarsine oxide and chloramine T respectively, mimicked the effect of H2O2, except for a drop in transcolonic resistance after 30 min. In contrast to the observed stimulatory effect on basal secretion, cAMP-stimulated electrogenic ion trans port was blunted by luminal H2O2. However, the Ca2+-activated response remained unchanged.CONCLUSION: H2O2 may be an important selective modulator of intestinal ion and water secretion in certain pathologic conditions such as inflammation or ischemiareperfusion by multiple mechanisms.

  20. Synthesis of 125 I - Salicyl Hydroxamic Acid for Urinary Bladder Imaging

    International Nuclear Information System (INIS)

    Salicylhydroxamic acid is a salicylate derivative. Radiolabeling of Salicyl hydroxamic acid ( SHA ) with iodine-125 may have considerable interest for imaging of urinary bladder. This study is aimed to optimize the radiolabeling yield of Salicyl hydroxamic with radio iodine (125-123) using chloramine - T (CAT) as an oxidizing agent with respect to factors that affect the reaction conditions such as SHA amount, CAT amount, reaction time and ph of the reaction mixture. In - vitro stability of the radiolabeled complex was checked and it was found to be stable for up to 24 h. 125 I-SHA was injected via intravenous administration routes into normal male Sprague – Dawley rats. Bio - distribution studies have revealed that 125I-SHA was excreted in urine with extent that it could give a clear image for urinary bladder especially if the bladder it tightly closed. The amount of 125 I - Salicyl hydroxamic excreted was increased in case of giving potassium bicarbonate to rat before injection of 125 I-SHA. The result of biodistribution study of 125 I - SHA in experimental animal suggest ed the possibility of using 123 I-SHA to image the urinary bladder

  1. Biochemical assays with radio-iodinated substrates

    International Nuclear Information System (INIS)

    A sensitive radiochemical method for the measurement of nanogram amounts of ammonia applicable to studies of enzymatic or other processes releasing or utilizing ammonia was developed. The method is based on a modified Berthelot reaction between ammonia and an aqueous alkaline solution of phenol and sodium hypochloride to yield indophenol. The radioactive tracer used is 125I-o-iodophenol, prepared by iodination of phenol with 125I by the chloramine-T method. A chloroform/carbon tetrachloride mixture is used to extract unreacted 125I-o-iodophenol from the reaction mixture; the 125I-labelled product remains in the aqueous phase and is measured by scintillation counting. Non-protein nitrogenous substances and certain other compounds interfere with the reaction, which cannot thus be used to measure ammonia directly in biological fluids. The glass Conway microdiffusion cell may, however, be utilized to isolate small amounts of ammonia from such fluids for measurement. The fluid is placed in the centre well of the cell and cold water in the outer well. Warm saturated potassium carbonate solution is then added to the centre well to expel the ammonia gas which is absorbed by the water. Technical details of the method are given

  2. Preparation of ( sup 123 I)- and ( sup 125 I)epidepride: a dopamine D-2 receptor antagonist radioligand

    Energy Technology Data Exchange (ETDEWEB)

    Clanton, J.A.; Schmidt, D.E.; Ansari, M.S.; Manning, R.G.; Kessler, R.M. (Vanderbilt Univ., Nashville, TN (United States). School of Medicine); Paulis, T. de (Vanderbilt Univ., Nashville, TN (United States). School of Medicine Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemistry); Baldwin, R.M. (Yale Univ., West Haven, CT (United States). Veterans Administration Medical Center Research)

    1991-07-01

    (S)-(-)-N-((1-ethyl-2-pyrrolidinyl)methyl)-5-({sup 123}I) iodo-2,3-dimethoxybenzamide (TDP 517) (proposed generic name, ({sup 123}I)epidepride) is the iodine-123 substituted analogue of isoremoxipride (FLB 457), both of which are very potent dopamine D-2 antagonists (epidepride K{sub D} 0.024 nM). ({sup 123}I) Epidepride was radioiodinated in 60-70% radiochemical yields in 35 min from the corresponding 5-(tributyltin) derivative using Na{sup 123}I with a specific radioactivity of 3000 Ci/mmol, and oxidized in situ with chloramine-T. The aryltin precursor was prepared from non-labelled epidepride by palladium-catalyzed stannylation using bis(tri-n-butyltin) in triethylamine. Alternatively, using no carrier-added Na{sup 125}I as the radioisotope, ({sup 125}I) epidepride at 2000 Ci/mmol specific radioactivity was prepared in 86% radiochemical yield and 99% radiochemical purity after purification by reverse phase HPLC in ethanolic phosphate buffer. (author).

  3. Preparation of 125I labelled nerve growth factor and study of its pharmacokinetics

    International Nuclear Information System (INIS)

    125I-Nerve growth factor (125I-NGF) with more than 95% of radiochemical purity is prepared by chloramine-T method. After I.V. and I.M. injection of 125I-NGF, pharmacokinetics of NGF in mice is determined by SDS-PAGE method. The results show that concentration-time curves after I.V. injection are fitted to a 2-compartment model are those after I.M. injection are fitted to a 1-compartment model. After I.V. injection of 25 μg/kg, the elimination half life (t1/2(β)) is 3.65 h. After I.M. injection of 75, 25, 10, 3.3 μg/kg, t1/2(β) is 1.79, 2.25, 2.30, 3.24 h, respectively. The mean plasma clearance (CLs) is 0.37 L/(h·kg), the appearance volume of distribution (Vd) is 1.18 L/kg and the mean residence time (tr-bar) in mice is 2.78 h. The pharmacokinetics of 125I-NGF in mice is useful for clinical trial

  4. Occurrence of disinfection byproducts in United States wastewater treatment plant effluents

    KAUST Repository

    Krasner, Stuart W.

    2009-11-01

    Effluents from wastewater treatment plants (WWTPs) contain disinfection byproducts (DBPs) of health concern when the water is utilized downstream as a potable water supply. The pattern of DBP formation was strongly affected by whether or not the WWTP achieved good nitrification. Chlorine addition to poorly nitrified effluents formed low levels of halogenated DBPs, except for (in some cases) dihalogenated acetic acids, but often substantial amounts of N-nitrosodimethyamine (NDMA). Chlorination of well-nitrified effluent typically resulted in substantial formation of halogenated DBPs but much less NDMA. For example, on a median basis after chlorine addition, the well-nitrified effluents had 57 μg/L of trihalomethanes [THMs] and 3 ng/L of NDMA, while the poorly nitrified effluents had 2 μg/L of THMs and 11 ng/L of NDMA. DBPs with amino acid precursors (haloacetonitriles, haloacetaldehydes) formed at substantial levels after chlorination of well-nitrified effluent. The formation of halogenated DBPs but not that of NDMA correlated with the formation of THMs in WWTP effluents disinfected with free chlorine. However, THM formation did not correlate with the formation of other DBPs in effluents disinfected with chloramines. Because of the relatively high levels of bromide in treated wastewater, bromine incorporation was observed in various classes of DBPs. © 2009 American Chemical Society.

  5. Iodine-123 labeled derivatives of methylphenidate: potential SPECT radiopharmaceuticals for brain dopamine transporters

    Energy Technology Data Exchange (ETDEWEB)

    Pan, D.; Gatley, S.J.; Chen, R.; Ding, Y.-S. [Brookhaven National Lab., Upton, NY (United States)

    1996-06-01

    Since dl-threo-[{sup 11}C]methylphenidate (Ritalin) and especially the more active enantiomer, d-threo-[{sup 11}C]methylphenidate, have favorable properties for PET studies, we prepared two radioiodinated analogs of methylphenidate, p-[{sup 123}I]iodomethylphenidate and m-[{sup 123}I]iodo-p-hydroxymethylphenidate with a view to evaluating them as potential SPECT tracers. To prepare p-[{sup 123}I]iodomethylphenidate, the p-tributyltin derivative was prepared from the previously reported p-bromomethylphenidate and reacted under acidic conditions with I-123 iodide plus chloramine-T at room temperature for 90 seconds. The predomimant radioactive product was obtained in 85% radiochemical yield and > 10 Ci/{mu}mol specific radioactivity after HPLC purification. It had the same HPLC retention time as a spectroscopically characterized non-radioactive p-iodomethylphenidate standard prepared via nitration of methylphenidate and diazotization, after protection of the secondary amino group by benzoylation. A second radioiodinated methylphenidate derivative, m-[{sup 123}I]iodop-hydroxymethylphenidate was prepared in 80% radiochemical yield by direct iodination of the known p-hydroxymethylphenidate. In this case the non-radioactive standard was prepared by iodination of p-hydroxyritalinic acid using I{sub 2} and iodic acid, followed by esterification. (author).

  6. Radioiodination of chicken erythrocyte histones H4 and H5 in chromatin.

    Science.gov (United States)

    Griffiths, G R; Huang, P C

    1979-08-25

    The conformational state of histones in isolated chicken erythrocyte chromatin was studied using procedures developed for probing surface proteins on membranes. Under controlled conditions, only exposed tyrosyl residues react with iodide radicals, generated either by the oxidant, chloramine-T (paratoluenesulfonyl chloramide), or the enzyme lactoperoxidase, giving monoidotyrosine. Using 125-iodine, this study compared the reactive tyrosines in free and bound histones H4, and H5. The relative extent of iodination of these histones within (H4) and outside (H5) of the nucleosomes was measured after extraction and gel electrophoresis. Each of the histones was further analyzed for the extent of specific tyrosine iodination by separating the tryptic peptides by high voltage electrophoresis. The identity of the labeled peptide was determined by dansylation of the amino acids present in each hydrolyzed peptide. The results show that there is a difference in the conformational arrangement of these histones on chromatin and in the free forms, since in chromatin not all tyrosine residues are as accessible for iodination as in the denatured state. Residue 53 of histone H5 for instance is more reactive than residues 28 and 58, indicating that the segments containing the latter residues are involved in either protein-DNA or protein-protein interactions. In histone H4, preferential labeling of 2 of the 4 tyrosines present was also observed.

  7. Plasma half-life and organ uptake ratio of radiolabeled glandular kallikrein in control and nephrectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, K.; Iwata, T.; Kokubu, T.

    1986-01-01

    The purified rat urinary kallikrein was radiolabeled by lactoperoxidase method and by chloramine T method. Plasma half-life of radiolabeled kallikrein was 5.06 +/- 0.59 (n = 5) min in control rats and 5.24 +/- 0.42 (n = 5) min in nephrectomized rats. There was no difference between two groups. From autoradiogram, main metabolic organs of radiolabeled kallikrein were liver, kidney and spleen. Total uptake of radiolabeled kallikrein in ech organ was the highest in liver (73.2%). The uptake per g tissue of radiolabeled kallikrein in each organ was high in liver (33.0%), kidney (31.4%) and spleen (21.1%). These results suggest that the active kallikrein is metabolized mainly in the liver, and kidney is not so an important organ to metabolize or to eliminate the active kallikrein in plasma. In order to clarify the mode of existence of active kallikrein in plasma, the following experiment was done by using disc gel electrophoresis. Radioactive profile of radiolabeled kallikrein showed one peak (Rf = 1.0), but radiolabeled kallikrein mixed with rat plasma showed two peaks, that is small peak (Rf = 1.0), and main peak (RF = 0.5). The most of radiolabeled kallikrein was bound to plasma protein and only five per cent was in free form. Furthermore, the binding of radiolabeled kallikrein to plasma protein was interfered by the addition of active kallikrein. These results suggest the possibility of existence of kallikrein binding protein in plasma.

  8. Oxidative radioiodination damage to human lactoferrin

    Energy Technology Data Exchange (ETDEWEB)

    Rosenmund, A.; Kuyas, C.; Haeberli, A.

    1986-11-15

    Oxidative iodination of human lactoferrin (Lf) commonly performed by using the chloramine-T, the Iodogen or the lactoperoxidase method produces an unreliable tracer protein because of excessive and heterogeneous polymer formation. Before iodination a minor tetramer fraction may be demonstrable in iron-saturated Lf only. /sup 125/I-Lf polymers are mainly covalently linked, as suggested by the lack of substantial dissociation in SDS/polyacrylamide-gel electrophoresis. Damage to the /sup 125/I-Lf monomer may be another consequence of oxidative iodination. This is demonstrated in SDS/polyacrylamide-gel electrophoresis where 50% of the radioactivity of apparently normal monomer (Msub(r) 75000) is displaced to a lower-Msub(r) region (30000-67000) after reduction with dithiothreitol. Non-oxidative iodination by the Bolton-Hunter technique produces an antigenetically stable tracer that is not being subjected to polymerization and monomer degradation as judged by high performance gel chromatography and SDS/polyacrylamide-gel electrophoresis with and without dithiothreitol treatment. It is concluded that oxidation in itself leads to covalent non-disulphide cross-linking between human Lf molecules and, possibly, to intramolecular peptide-bond breaking becoming unmasked under reducing conditions.

  9. Selective mono-radioiodination and characterization of a cell-penetrating peptide. L-Tyr-maurocalcine

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadi, Mitra; Bacot, Sandrine; Perret, Pascale; Riou, Laurent; Ghezzi, Catherine [Universite Joseph Fourier, Grenoble (France); INSERM U1039, Grenoble (France). Radiopharmaceutiques Biocliniques; Poillot, Cathy; Cestele, Sandrine [INSERM U836, Grenoble (France). Grenoble Inst. of Neuroscience; Universite Joseph Fourier, Grenoble (France); Desruet, Marie-Dominique [INSERM U1039, Grenoble (France). Radiopharmaceutiques Biocliniques; Couvet, Morgane; Bourgoin, Sandrine; Seve, Michel [CRI-INSERM U823, Grenoble (France). Inst. of Albert Bonniot; Universite Joseph Fourier, Grenoble (France); Waard, Michel de [INSERM U836, Grenoble (France). Grenoble Inst. of Neuroscience; Universite Joseph Fourier, Grenoble (France); Smartox Biotechnologies, Grenoble (France)

    2014-07-01

    Mono-and poly-iodinated peptides form frequently during radioiodination procedures. However, the formation of a single species in its mono-iodinated form is essential for quantitative studies such as determination of tissue concentration or image quantification. Therefore, the aim of the present study was to define the optimal experimental conditions in order to exclusively obtain the mono-iodinated form of L-maurocalcine (L-MCa). L-MCa is an animal venom toxin which was shown to act as a cell-penetrating peptide. In order to apply the current direct radioiodination technique using oxidative agents including chloramine T, Iodo-Gen {sup registered} or lactoperoxidase, an analogue of this peptide containing a tyrosine residue (Tyr-L-MCa) was synthesized and was shown to fold/oxidize properly. The enzymatic approach using lactoperoxidase/H{sub 2}O{sub 2} was found to be the best method for radioiodination of Tyr-L-MCa. MALDI-TOF mass spectrometry analyses were then used for identification of the chromatographic eluting components of the reaction mixtures. We observed that the production of different radioiodinated species depended upon the reaction conditions. Our results successfully described the experimental conditions of peptide radioiodination allowing the exclusive production of the mono-iodinated form with high radiochemical purity and without the need for a purification step. Mono-radioiodination of L-Tyr-MCa will be crucial for future quantitative studies, investigating the mechanism of cell penetration and in vivo biodistribution.

  10. Preparation and properties of /sup 3/H-phe/sup B1/ insulin

    Energy Technology Data Exchange (ETDEWEB)

    Grant, K.I.

    1986-01-01

    Insulin iodinated by both the lactoperoxidase and chloramine-T methods was found in accordance with many published reports to bind to plasma membrane. It was found, however not to obey isotope dilution laws in its displacement from plasma membrane by natural insulin. It was shown to be heterogeneous on reverse-phase HPLC, to contain diiodotyrosine and to have a reduced biological activity in an in vivo assay. Thus an insulin labelled semi-synthetically with /sup 3/H-phenylalaine at position B1 was prepared. A method already published was attempted, but without success. A different scheme of synthesis was developed using 2-t-butoxycarbonyloxyimino-2-phenylacetonitrile as the t-butoxycarbonylating agent and HPLC as the mode of separation of insulin derivatives. Using L-(2,3,4,5,6-/sup 3/H) phenylalaine a labelled insulin of specific radioactivity of 60 Ci/mmole was made. Characterization by the techniques of HPLC, acid-urea polyacrylamide gel electrophoresis, dansylation, Edman degradation and gel exclusion chromatography showed the labelled insulin to be indistinguishable from the natural hormone, and to contain a single covalently bound /sup 3/H-phe residue.

  11. Biologically active monoiodinated alpha-MSH derivatives for receptor binding studies using human melanoma cells

    International Nuclear Information System (INIS)

    Three different monoiodinated radioligands of alpha-MSH (alpha-melanocyte-stimulating hormone) were compared in a binding assay with human D10 melanoma cells: [Tyr(125I)2]-alpha-MSH, [Tyr(125I)2,NIe4]-alpha-MSH, and [Tyr(125I)2,NIe4,D-Phe7]-alpha-MSH. They were prepared either by the classical chloramine T method or by the Enzymobead method. A simple and rapid purification scheme was developed consisting of a primary separation on reversed-phase C18 silica cartridges immediately after the iodination, followed by HPLC purification before each binding experiment. Biological testing of the three radioligands showed that they all retained high melanotropic activity in the B16 melanin assay and the Anolis melanophore assay. However, in human D10 melanoma cells, [Tyr(125I)2,NIe4]-alpha-MSH led to a high degree of non-specific binding to the cells which could not be displaced by excess alpha-MSH and only partially by [NIe4]-alpha-MSH. The [Tyr(125I)2,NIe4,D-Phe7]-alpha-MSH tracer gave similar results but with a much lower proportion of non-specific binding. On the other hand, [Tyr(125I)2]-alpha-MSH proved to be an excellent radioligand whose non-specific binding to the D10 cells was not higher than 20% of the total binding

  12. Selective chlorination of natural organic matter: identification of previously unknown disinfection byproducts.

    Science.gov (United States)

    Lavonen, Elin E; Gonsior, Michael; Tranvik, Lars J; Schmitt-Kopplin, Philippe; Köhler, Stephan J

    2013-03-01

    Natural organic matter (NOM) serve as precursors for disinfection byproducts (DBPs) in drinking water production making NOM removal essential in predisinfection treatment processes. We identified molecular formulas of chlorinated DBPs after chlorination and chloramination in four Swedish surface water treatment plants (WTPs) using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Chlorine-containing formulas were detected before and after disinfection and were therefore classified to identify DBPs. In total, 499 DBPs were detected, of which 230 have not been reported earlier. The byproducts had, as a group, significantly lower ratio of hydrogen to carbon (H/C) and significantly higher average carbon oxidation state (COS), double bond equivalents per carbon (DBE/C) and ratio of oxygen to carbon (O/C) compared to Cl-containing components present before disinfection and CHO formulas in samples taken both before and after disinfection. Electrophilic substitution, the proposed most significant reaction pathway for chlorination of NOM, results in carbon oxidation and decreased H/C while O/C and DBE/C is left unchanged. Because the identified DBPs had significantly higher DBE/C and O/C than the CHO formulas we concluded that chlorination of NOM during disinfection is selective toward components with relatively high double bond equivalency and number of oxygen atoms per carbon. Furthermore, choice of disinfectant, dose, and predisinfection treatment at the different WTPs resulted in distinct patterns in the occurrence of DBP formulas.

  13. Occurrence of regulated and emerging iodinated DBPs in the Shanghai drinking water.

    Science.gov (United States)

    Wei, Xiao; Chen, Xin; Wang, Xia; Zheng, Weiwei; Zhang, Dong; Tian, Dajun; Jiang, Songhui; Ong, Choon Nam; He, Gengsheng; Qu, Weidong

    2013-01-01

    Drinking water chlorination plays a pivotal role in preventing pathogen contamination against water-borne disease. However, chemical disinfection leads to the formation of halogenated disinfection by products (DBPs). Many DBPs are highly toxic and are of health concern. In this study, we conducted a comprehensive measurements of DBPs, including iodoacetic acid (IAA), iodoform (IF), nine haloacetic acids and four trihalomethanes in drinking waters from 13 water plants in Shanghai, China. The results suggested that IAA and IF were found in all the water treatment plants, with maximum levels of 1.66 µg/L and 1.25 µg/L for IAA and IF, respectively. Owing to deterioration of water quality, the Huangpu River has higher IAA and IF than the Yangtze River. Our results also demonstrated that low pH, high natural organic matter, ammonia nitrogen, and iodide in source waters increased IAA and IF formation. Compared to chlorine, chloramines resulted in higher concentration of iodinated DBP, but reduced the levels of trihalomethanes. This is the first study to reveal the widespread occurrence of IAA and IF in drinking water in China. The data provide a better understanding on the formation of iodinated disinfection byproducts and the findings should be useful for treatment process improvement and disinfection byproducts controls.

  14. Research Overview of Formation Mechanism for Typical Nitrogenous Disinfection Byproducts (DBPs)-Nitrosamines in Drinking Water%饮用水典型含氮消毒副产物亚硝胺类的生成机制研究综述

    Institute of Scientific and Technical Information of China (English)

    周超

    2014-01-01

    Nitrosamines are a group of emerging disinfection by-products formed during chlorine-based and chloramine-based water treatment,which have caused great attention because of their strong toxicity. The studies mainly focus on the occurrence and formation mechanism of typical nitrogenous disinfection byproducts-nitrosamines (NAms)in drinking water. In the light of some shortcomings existing,main research fields in the future and problems to be solved are proposed.%亚硝胺类是饮用水消毒处理过程中产生的一类典型含氮消毒副产物,其强烈的“三致”毒性引起人们越来越多的关注。该文从浓度分布和生成机制两个方面对亚硝胺类进行系统的分析,并针对现有亚硝胺类研究的不足之处,提出了今后研究的主要方向和需解决的问题。

  15. Free Radical Chemistry of Disinfection Byproducts. 3. Degradation Mechanisms of Chloronitromethane, Bromonitromethane and Dichloronitromethane

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J. Mincher; Stephen P. Mezyk; William J. Cooper; S. Kirkham Cole; Robert V. Fox; Piero R. Gardinali

    2010-01-01

    Halonitromethanes (HNMs) are byproducts formed through ozonation and chlorine/ chloramine disinfection processes in drinking waters that contain dissolved organic matter and bromide ions. These species occur at low concentration, but have been determined to have high cytotoxicity and mutagenicity and therefore may represent a human health hazard. In this study, we have investigated the chemistry involved in the mineralization of HNMs to non-hazardous inorganic products through the application of advanced oxidation and reduction processes. We have combined measured absolute reaction rate constants for the reactions of chloronitromethane, bromonitromethane and dichloronitromethane with the hydroxyl radical and the hydrated electron with a kinetic computer model in an attempt to elucidate the reaction pathways of these HNMs. The results are compared to measurements of stable products resulting from steady-state 60Co y-irradiations of the same compounds. The model predicted the decomposition of the parent compounds and ingrowth of chloride and bromide ions with excellent accuracy, but the prediction of the total nitrate ion concentration was slightly in error, reflecting the complexity of nitrogen oxide species reactions in irradiated solution.

  16. Occurrence of regulated and emerging iodinated DBPs in the Shanghai drinking water.

    Directory of Open Access Journals (Sweden)

    Xiao Wei

    Full Text Available Drinking water chlorination plays a pivotal role in preventing pathogen contamination against water-borne disease. However, chemical disinfection leads to the formation of halogenated disinfection by products (DBPs. Many DBPs are highly toxic and are of health concern. In this study, we conducted a comprehensive measurements of DBPs, including iodoacetic acid (IAA, iodoform (IF, nine haloacetic acids and four trihalomethanes in drinking waters from 13 water plants in Shanghai, China. The results suggested that IAA and IF were found in all the water treatment plants, with maximum levels of 1.66 µg/L and 1.25 µg/L for IAA and IF, respectively. Owing to deterioration of water quality, the Huangpu River has higher IAA and IF than the Yangtze River. Our results also demonstrated that low pH, high natural organic matter, ammonia nitrogen, and iodide in source waters increased IAA and IF formation. Compared to chlorine, chloramines resulted in higher concentration of iodinated DBP, but reduced the levels of trihalomethanes. This is the first study to reveal the widespread occurrence of IAA and IF in drinking water in China. The data provide a better understanding on the formation of iodinated disinfection byproducts and the findings should be useful for treatment process improvement and disinfection byproducts controls.

  17. Selective mono-radioiodination and characterization of a cell-penetrating peptide. L-Tyr-maurocalcine

    International Nuclear Information System (INIS)

    Mono-and poly-iodinated peptides form frequently during radioiodination procedures. However, the formation of a single species in its mono-iodinated form is essential for quantitative studies such as determination of tissue concentration or image quantification. Therefore, the aim of the present study was to define the optimal experimental conditions in order to exclusively obtain the mono-iodinated form of L-maurocalcine (L-MCa). L-MCa is an animal venom toxin which was shown to act as a cell-penetrating peptide. In order to apply the current direct radioiodination technique using oxidative agents including chloramine T, Iodo-Gen registered or lactoperoxidase, an analogue of this peptide containing a tyrosine residue (Tyr-L-MCa) was synthesized and was shown to fold/oxidize properly. The enzymatic approach using lactoperoxidase/H2O2 was found to be the best method for radioiodination of Tyr-L-MCa. MALDI-TOF mass spectrometry analyses were then used for identification of the chromatographic eluting components of the reaction mixtures. We observed that the production of different radioiodinated species depended upon the reaction conditions. Our results successfully described the experimental conditions of peptide radioiodination allowing the exclusive production of the mono-iodinated form with high radiochemical purity and without the need for a purification step. Mono-radioiodination of L-Tyr-MCa will be crucial for future quantitative studies, investigating the mechanism of cell penetration and in vivo biodistribution.

  18. Sporicidal/bactericidal textiles via the chlorination of silk.

    Science.gov (United States)

    Dickerson, Matthew B; Lyon, Wanda; Gruner, William E; Mirau, Peter A; Slocik, Joseph M; Naik, Rajesh R

    2012-03-01

    Bacterial spores, such as those of the Bacillus genus, are extremely resilient, being able to germinate into metabolically active cells after withstanding harsh environmental conditions or aggressive chemical treatments. The toughness of the bacterial spore in combination with the use of spores, such as those of Bacillus anthracis, as a biological warfare agent necessitates the development of new antimicrobial textiles. In this work, a route to the production of fabrics that kill bacterial spores and cells within minutes of exposure is described. Utilizing this facile process, unmodified silk cloth is reacted with a diluted bleach solution, rinsed with water, and dried. The chlorination of silk was explored under basic (pH 11) and slightly acidic (pH 5) conditions. Chloramine-silk textiles prepared in acidified bleach solutions were found to have superior breaking strength and higher oxidative Cl contents than those prepared under caustic conditions. Silk cloth chlorinated for ≥1 h at pH 5 was determined to induce >99.99996% reduction in the colony forming units of Escherichia coli, as well as Bacillus thuringiensis Al Hakam (B. anthracis simulant) spores and cells within 10 min of contact. The processing conditions presented for silk fabric in this study are highly expeditionary, allowing for the on-site production of protein-based antimicrobial materials from a variety of agriculturally produced feed-stocks.

  19. Studies into the radiobromination and -iodination of aromatic compounds with n-halogen compounds without addition of carriers

    International Nuclear Information System (INIS)

    There is a special need for radiohalogenated compounds for diagnostic nuclear medicine, in particular for no-carrier-added (nca) short lived cyclotron products. In this study the applicability of chloramine-T (CAT) and dichloramine-T (DCT) has been demonstrated for nca-radiohalogenation with bromine-75, 77 and iodine-123 in aqueous and organic solvents. Radio gaschromatography and -HPLC are used for product analysis. In aqueous solution the optimum reaction conditions with respect to pH, concentration of CAT, reaction time and added bromide-carrier are determined using tyrosine as a model substrate. The suitability of the CAT method for radiobrominations under convenient and mild conditions is demonstrated for some biomolecules such as amino acids and nucleobases as well as for peptides and the proteins urokinase and HSA. Dichloramine-T is found to be a new efficient reagent for radiobromination and -iodination of aromatic compounds in various organic solvents such as acetic acid, dichloromethane or carbontetrachloride. A high para-selectivity is observed and the radiochemical yields (80%) are as high as in aqueous solution. A comparison of this reagent with different in-situ halogenation agents show that DCT is superior with respect to reaction time, concentration of the reagent and thus oxidative side reactions, and ease of handling. (orig./RB)

  20. Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems.

    Science.gov (United States)

    Scott, Daniel B; Van Dyke, Michele I; Anderson, William B; Huck, Peter M

    2015-12-01

    The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence-absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems. PMID:26518069

  1. Variation of hydroxyproline content after local injection hyaluronic acid in excessive dermal scar of rabbit ears%透明质酸注射兔耳瘢痕后羟脯氨酸含量变化

    Institute of Scientific and Technical Information of China (English)

    张阳; 柳大烈; 李希军; 李玉霞; 张选奋; 安书杰

    2002-01-01

    AIM To observe the scar formation by using hyaluronic acid (HA) and hyaluronidase (HAse) in excessive dermal scar of rabbit ears. METHODS Upon the foundation of hypertrophic scar model in rabbit ears, we tested the content of hydroxyproline (HPr) using chloramineT method by injecting HA and HAse in excessive dermal scar of rabbit ears with the establishment of saline and blank control at different time. RESULTS ① HPr contents of the HA, saline and blank groups were gradullay increased (P0.05); ③ Compared with saline group, HPr contents of the HA group were higher (P0.05);③HA组的HPr含量明显高于盐水组(P<0.05);④HAse组的HPr含量明显低于盐水组(P<0.01);⑤HA组的HPr含量明显高于HAse组(P<0.01).结论瘢痕组织中注射HA后胶原合成增加, 提示瘢痕组织中, HA含量的持续增高可导致瘢痕的异常增生.

  2. [Inactivation of the chlorine-resistant bacteria isolated from the drinking water distribution system].

    Science.gov (United States)

    Chen, Yu-Qiao; Duan, Xiao-Di; Lu, Pin-Pin; Wang, Qian; Zhang, Xiao-Jian; Chen, Chao

    2012-01-01

    Inactivation experiments of seven strains of chlorine-resistant bacteria, isolated from a drinking water distribution system, were conducted with four kinds of disinfectants. All the bacteria showed high resistance to chlorine, especially for Mycobacterium mucogenicum. The CT value of 99.9% inactivation for M. mucogenicum, Sphingomonas sanguinis and Methylobacterium were 120 mg x (L x min)(-1), 7 mg x (L x min)(-1) and 4 mg x (L x min)(-1), respectively. The results of inactivation experiments showed that chlorine dioxide and potassium monopersulfate could inactive 5 lg of M. mucogenicum within 30 min, which showed significantly higher efficiency than free chlorine and monochloramine. Free chlorine was less effective because the disinfectant decayed very quickly. Chloramination needed higher concentration to meet the disinfection requirements. The verified dosage of disinfectants, which could effectively inactivate 99.9% of the highly chlorine-resistant M. mucogenicum within 1 h, were 3.0 mg/L monochloramine, 1.0 mg/L chlorine dioxide (as Cl2), and 1.0 mg/L potassium monopersulfate (as Cl2). It was suggested that the water treatment plants increase the concentration of monochloramine or apply chlorine dioxide intermittently to control the disinfectant-resistant bacteria.

  3. Evaluation of Bacteriological and Chemical Quality of Dialysis Water and Fluid in Isfahan, Central Iran

    Science.gov (United States)

    SHAHRYARI, Ali; NIKAEEN, Mahnaz; HATAMZADEH, Maryam; VAHID DASTJERDI, Marzieh; HASSANZADEH, Akbar

    2016-01-01

    Background: Chemical and microbial quality of water used in hemodialysis play key roles in a number of dialysis-related complications. In order to avoid the complications and to guarantee safety and health of patients therefore, vigorous control of water quality is essential. The objective of present study was to investigate the chemical and bacteriological characteristics of water used in dialysis centers of five hospitals in Isfahan, central Iran. Methods: A total of 30 water samples from the input of dialysis purification system and dialysis water were analyzed for chemical parameters. Heterotrophic plate count and endotoxin concentration of drinking water, dialysis water and dialysis fluid of 40 machines were also monitored over a 5-month period in 2011–2012. Results: Concentration of the determined chemicals (copper, zinc, sulfate, fluoride, chloramines and free chlorine) did not exceed the recommended concentration by the Association for the Advancement of Medical Instrumentation (AAMI) exclude lead, nitrate, aluminum and calcium. Furthermore, the magnesium; cadmium and chromium concentration exceeded the maximum level in some centers. No contamination with heterotrophic bacteria was observed in all samples, while the AMMI standard for endotoxin level in dialysis fluid (water and fluid failed to meet the all chemical and bacteriological requirements for hemodialysis. To minimize the risk of contaminants for hemodialysis patients therefore, a water quality management program including monitoring, maintenance and development of water treatment system in hemodialysis centers is extremely important. In addition, an appropriate disinfection program is needed to guarantee better control of bacterial growth and biofilm formation. PMID:27398338

  4. Manganese deposition in drinking water distribution systems.

    Science.gov (United States)

    Gerke, Tammie L; Little, Brenda J; Barry Maynard, J

    2016-01-15

    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality.

  5. Studies on the mode of action of calciferol. XIII. Development of a radioimmunoassay for vitamin D-dependent chick intestinal calcium-binding protein and tissue distribution

    International Nuclear Information System (INIS)

    A RIA for chick intestinal calcium-binding protein (CaBP) has been developed with a sensitivity of 1 ng. The antiserum was generated in rabbits injected with highly purified vitamin D-dependent chick intestinal CaBP. The assay employs the double antibody technique, and 125I-labeled CaBP was prepared using chloramine T. Low molecular weight peptide hormones and normal rabbit, rat, and human serum proteins show no cross-reactivity in the assay. Measurements of chick intestinal and kidney CaBP by RIA showed a good correlation with measurements of CaBP by the radial immunodiffusion method. The assay is reproducible (interassay variability, 16.3%) and precise (intraassay variability, 4.0%). The concentration of immunoreactive CaBP (iCaBP) in chick serum (2.7 ng/ml serum) can now be measured as early as 8 h after the administration of 6.5 nmol 1,25-dihydroxyvitamin D3; a maximum of 11 ng/ml is reached at 20 h. The level of CaBP in chick serum was found to be dependent on the dose of vitamin D3 or 1,25-dihydroxyvitamin D3 administered to the animal

  6. Studies on the mode of action of calciferol. XIII. Development of a radioimmunoassay for vitamin D-dependent chick intestinal calcium-binding protein and tissue distribution

    Energy Technology Data Exchange (ETDEWEB)

    Christakos, S.; Friedlander, E.J.; Frandsen, B.R.; Norman, A.W.

    1979-05-01

    A RIA for chick intestinal calcium-binding protein (CaBP) has been developed with a sensitivity of 1 ng. The antiserum was generated in rabbits injected with highly purified vitamin D-dependent chick intestinal CaBP. The assay employs the double antibody technique, and /sup 125/I-labeled CaBP was prepared using chloramine T. Low molecular weight peptide hormones and normal rabbit, rat, and human serum proteins show no cross-reactivity in the assay. Measurements of chick intestinal and kidney CaBP by RIA showed a good correlation with measurements of CaBP by the radial immunodiffusion method. The assay is reproducible (interassay variability, 16.3%) and precise (intraassay variability, 4.0%). The concentration of immunoreactive CaBP (iCaBP) in chick serum (2.7 ng/ml serum) can now be measured as early as 8 h after the administration of 6.5 nmol 1,25-dihydroxyvitamin D/sub 3/; a maximum of 11 ng/ml is reached at 20 h. The level of CaBP in chick serum was found to be dependent on the dose of vitamin D/sub 3/ or 1,25-dihydroxyvitamin D/sub 3/ administered to the animal.

  7. Dynamic behavior of histone H1 microinjected into HeLa cells

    International Nuclear Information System (INIS)

    Histone H1 was purified from bovine thymus and radiolabeled with tritium by reductive methylation or with 125I using chloramine-T. Red blood cell-mediated microinjection was then used to introduce the labeled H1 molecules into HeLa cells synchronized in S phase. The injected H1 molecules rapidly entered HeLa nuclei, and a number of tests indicate that their association with chromatin was equivalent to that of endogenous histone H1. The injected molecules copurified with HeLa cell nucleosomes, exhibited a half-life of ∼100h, and were hyperphosphorylated at mitosis. When injected HeLa cells were fused with mouse 3T3 fibroblasts < 10% of the labeled H1 molecules migrated to mouse nuclei during the next 48 h. Despite their slow rate of migration between nuclei, the injected H1 molecules were evenly distributed on mouse and human genomes soon after mitosis of HeLa-3T3 heterokaryons. These results suggest that although most histone H1 molecules are stably associated with interphase chromatin, they undergo extensive redistribution after mitosis

  8. The study of labeling with Iodine-131 of monoclonal antibody anti-CD20 used for the treatment of non-Hodgkin lymphoma

    International Nuclear Information System (INIS)

    Lymphomas are malignancies of the lymphatic system, described by Thomas Hodgkin in 1932. Traditionally, lymphomas are classified in two basic groups: Hodgkin disease and non-Hodgkin lymphoma (NHL). Patients with NHL were earlier treated with radiotherapy alone or in combination with immunotherapy using monoclonal antibody anti-CD20 (ex., Rituximab-Mabthera, Roche). However, Radioimmunotherapy is a new modality of treatment for patients with NHL, in which cytotoxic radiation from therapeutic radioisotopes is delivered to tumors through monoclonal antibodies. This study focused on labeling conditions of monoclonal antibody anti-CD20 (Rituximab-Mabthera, Roche) with iodine-131, by direct radioiodination method using Chloramine-T as oxidizing agent. Labeling parameters investigated were: Radiochemical purity (RP), method of purification, incubation time, antibody mass, oxidative agent mass, stability in vitro, stability in vivo, immunoreactivity and biological distribution performed in normal Swiss mouse. Product of high radiochemical purity was obtained with no notable difference between the methods applied. No clear evidence of direct influence of incubation time on radiochemical purity of the labeled antibody was observed. Whereas, a clear evidence of direct influence of activity on radiochemical purity of the labeled antibody was observed when antibody mass was varied. After purification, the labeled product presented radiochemical purity of approximately 100 %. Product of superior radiochemical yield was observed when standard condition of labeling was used. The labeled product presented variation in radiochemical purity using five different stabilizer conditions. The condition in which gentisic acid was combined with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with high therapeutic activity of iodine-131. The labeled product presented low immunoreactivity when compared to the literature. Biological distribution in

  9. The study of labeling with iodine-131 of monoclonal antibody anti-CD20 used for the treatment of non-Hodgkin lymphoma

    International Nuclear Information System (INIS)

    Lymphomas are malignancies of the lymphatic system, described by Thomas Hodgkin in 1932. Traditionally, lymphomas are classified in two basic groups: Hodgkin disease and non-Hodgkin lymphoma (NHL). Patients with NHL were earlier treated with radiotherapy alone or in combination with immunotherapy using monoclonal antibody anti-CD20 (ex., Rituximab-Mabthera, Roche). However, Radioimmunotherapy is a new modality of treatment for patients with NHL, in which cytotoxic radiation from therapeutic radioisotopes is delivered to tumors through monoclonal antibodies. This study focused on labeling conditions of monoclonal anti-CD20 (ex., Rituximab-Mabthera, Roche) with iodine-131, by direct radioiodination method using Chloramine-T as oxidizing agent. Labeling parameters investigated were: Radiochemical purity (RP), method of purification, incubation time, antibody mass, oxidative agent mass, stability in vitro, immunoreactivity and biological distribution performed in normal Swiss mouse. Product of high radiochemical purity was obtained with no notable difference between the methods applied. No clear evidence of direct influence of incubation time on radiochemical purity of the labeled antibody was observed. Whereas, a clear evidence of direct influence of activity on radiochemical purity of the labeled antibody was varied. After purification the labeled product presented radiochemical purity of approximately 100 %. Product of superior radiochemical yield was observed when standard condition of labeling was used. The labeled product presented variation in radiochemical purity using five different stabilizer conditions. The condition in which gentisic acid combined with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with high therapeutic activity of iodine-131. The labeled product presented low immunoreactivity when compared to the

  10. The study of labeling with Iodine-131 of monoclonal antibody anti-CD20 used for the treatment of non-Hodgkin lymphoma; Estudo de marcacao com Iodo-131 de anticorpo monoclonal anti-CD20 na terapia de linfoma nao-Hodgkin

    Energy Technology Data Exchange (ETDEWEB)

    Akanji, Akinkunmi Ganiyu

    2006-07-01

    Lymphomas are malignancies of the lymphatic system, described by Thomas Hodgkin in 1932. Traditionally, lymphomas are classified in two basic groups: Hodgkin disease and non-Hodgkin lymphoma (NHL). Patients with NHL were earlier treated with radiotherapy alone or in combination with immunotherapy using monoclonal antibody anti-CD20 (ex., Rituximab-Mabthera, Roche). However, Radioimmunotherapy is a new modality of treatment for patients with NHL, in which cytotoxic radiation from therapeutic radioisotopes is delivered to tumors through monoclonal antibodies. This study focused on labeling conditions of monoclonal antibody anti-CD20 (Rituximab-Mabthera, Roche) with iodine-131, by direct radioiodination method using Chloramine-T as oxidizing agent. Labeling parameters investigated were: Radiochemical purity (RP), method of purification, incubation time, antibody mass, oxidative agent mass, stability in vitro, stability in vivo, immunoreactivity and biological distribution performed in normal Swiss mouse. Product of high radiochemical purity was obtained with no notable difference between the methods applied. No clear evidence of direct influence of incubation time on radiochemical purity of the labeled antibody was observed. Whereas, a clear evidence of direct influence of activity on radiochemical purity of the labeled antibody was observed when antibody mass was varied. After purification, the labeled product presented radiochemical purity of approximately 100 %. Product of superior radiochemical yield was observed when standard condition of labeling was used. The labeled product presented variation in radiochemical purity using five different stabilizer conditions. The condition in which gentisic acid was combined with freeze appears more suitable and capable of minimizing autoradiolysis of the antibody labeled with high therapeutic activity of iodine-131. The labeled product presented low immunoreactivity when compared to the literature. Biological distribution in

  11. Nano-silver in drinking water and drinking water sources: stability and influences on disinfection by-product formation.

    Science.gov (United States)

    Tugulea, A-M; Bérubé, D; Giddings, M; Lemieux, F; Hnatiw, J; Priem, J; Avramescu, M-L

    2014-10-01

    Nano-silver is increasingly used in consumer products from washing machines and refrigerators to devices marketed for the disinfection of drinking water or recreational water. The nano-silver in these products may be released, ending up in surface water bodies which may be used as drinking water sources. Little information is available about the stability of the nano-silver in sources of drinking water, its fate during drinking water disinfection processes, and its interaction with disinfection agents and disinfection by-products (DBPs). This study aims to investigate the stability of nano-silver in drinking water sources and in the finished drinking water when chlorine and chloramines are used for disinfection and to observe changes in the composition of DBPs formed when nano-silver is present in the source water. A dispersion of nano-silver particles (10 nm; PVP-coated) was used to spike untreated Ottawa River water, treated Ottawa River water, organic-free water, and a groundwater at concentrations of 5 mg/L. The diluted dispersions were kept under stirred and non-stirred conditions for up to 9 months and analyzed weekly using UV absorption to assess the stability of the nano-silver particles. In a separate experiment, Ottawa River water containing nano-silver particles (at 0.1 and 1 mg/L concentration, respectively) was disinfected by adding sodium hypochlorite (a chlorinating agent) in sufficient amounts to maintain a free chlorine residual of approximately 0.4 mg/L after 24 h. The disinfected drinking water was then quenched with ascorbic acid and analyzed for 34 neutral DBPs (trihalomethanes, haloacetonitriles, haloacetaldehydes, 1,1 dichloro-2-propanone, 1,1,1 trichloro-2-propanone, chloropicrin, and cyanogen chloride). The results were compared to the profile of DBPs obtained under the same conditions in the absence of nano-silver and in the presence of an equivalent concentration of Ag(+) ions (as AgNO3). The stability of the nano-silver dispersions in

  12. 在饮水中典型溶解性有机氮酪氨酸氯化生成氯仿的机理分析%The Mechanism Analysis of Formation of Chloroform during Typical Dissolved Organic Nitrogen Tyrosine Chlorination in Drinking Water

    Institute of Scientific and Technical Information of China (English)

    楚文海; 高乃云; 赵世嘏; 邓慧萍

    2009-01-01

    Chlorination disinfection of drinking water effectively prevents waterborne diseases, but results in unintended disinfection byproducts (DBPs) from the reactions between organic materials in water and disinfectants. As alanine (Ala), phenylalanine (Phe) and tyrosine (Tyr) exist in much source water, the chlorination characteristic of the three amino acids (AA) and the formation pathways for chloroform (CF) during chlorination of model Tyr were studied. Chlorine demand and CF yield of the important intermediate product 2,4,6-trichlorophenol (2,4,6-TCP) were also examined. The results indicated that chlorine demand and CF yield of Tyr were much higher than those of Ala and Phe based on the same chlorination conditions, which indicated that Tyr was an important precursor of CF. Based on the analysis of GC/MS and calculation of frontier electron densities (FED~2), the formation pathway of CF during chlorination of Tyr was proposed as Tyr→4-monochlorophenol (4-MCP) → 2,4-dichlorophenol (2,4-DCP) →2,4,6-TCP →CF. The yields of CF and 2,4,6-TCP could be reduced by switching chlorination to chloramination. However, the disinfec-tion performance of chloramination is inferior to chlorination. The removal of precursor (Tyr, etc.) before disinfection may be a more promising method to reduce the generation of CF.%饮用水氯化消毒可以有效杀灭细菌,但同时会产生危害人体健康的消毒副产物(DBP).DBP生成机理研究是有效控制DBP的前提.溶解性有机氮(DON)是DBP的重要前体物,选取典型DON-丙氨酸(Ala)、苯丙氨酸(Phe)和酪氨酸(Tyr作为氯仿(CF)等DBP的前体物,研究三种氨皋酸(AA)的耗氯量和CF产率;同时考察了Tyr氯化中间产物2,4,6-TCP的氯化特性和CF产率;采用GC/MS扫描和前线轨道理论验证,探讨了CF的主要生成路径.研究发现,在同等氯化反应条件下,由于侧链基团的不同,Tyr的耗氯量以及CF产率都明显高于Ala和Phe,从而说明Tyr确实是一种重要

  13. Formation of N-nitrosamines from eleven disinfection treatments of seven different surface waters.

    Science.gov (United States)

    Zhao, Yuan-Yuan; Boyd, Jessica M; Woodbeck, Matthew; Andrews, Robert C; Qin, Feng; Hrudey, Steve E; Li, Xing-Fang

    2008-07-01

    Formation of nine N-nitrosamines has been investigated when seven different source waters representing various qualities were each treated with eleven bench-scale disinfection processes, without addition of nitrosamine precursors. These disinfection treatments included chlorine (OCl-), chloramine (NH2Cl), chlorine dioxide (ClO2), ozone (O3), ultraviolet (UV), advanced oxidation processes (AOP), and combinations. The total organic carbon (TOC) of the seven source waters ranged from 2 to 24 mg x L(-1). The disinfected water samples and the untreated source waters were analyzed for nine nitrosamines using a solid phase extraction and liquid chromatography-tandem mass spectrometry method. Prior to any treatment, N-nitrosodimethylamine (NDMA) was detected ranging from 0 to 53 ng x L(-1) in six of the seven source waters, and its concentrations increased in the disinfected water samples (0-118 ng x L(-1)). N-nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMor), and N-nitrosodiphenylamine (NDPhA) were also identified in some of the disinfected water samples. NDPhA (0.2-0.6 ng x L(-1)) was formed after disinfection with OCl-, NH2Cl, O3, and MPUV/OCl-. NMEA was produced with OCl- and MPUV/OCl-, and NMor formation was associated with O3. In addition, UVtreatment alone degraded NDMA; however, UV/ OCl- and AOP/OCl- treatments produced higher amounts of NDMA compared to UV and AOP alone, respectively. These results suggest that UV degradation or AOP oxidation treatment may provide a source of NDMA precursors. This study demonstrates that environmental concentrations and mixtures of unknown nitrosamine precursors in source waters can form NDMA and other nitrosamines.

  14. Two Fatal Intoxications with Cyanohydrins.

    Science.gov (United States)

    Zheng, Shuiqing; Yuan, Xiaoliang; Wang, Wei; Liang, Chen; Cao, Fangqi; Zhang, Runsheng

    2016-06-01

    Cyanohydrins, also be called cyanoalcohols, are important industrial precursors to carboxylic acids and some amino acids. Acetone cyanohydrin (ACH) and formaldehyde cyanohydrin (glycolonitrile, FCH), which are the typical examples of cyanohydrins, are classified as extremely hazardous substances. As the cyanohydrins can readily decompose, and it is hard to find cyanohydrins in gastric contents and heart blood, the determination study in biological samples can be divided into two parts: the first is the determination of HCN by using a Prussian blue reaction and the HS-GC-MSD after derivatization by chloramine-T. The second is the determination of acetone or formaldehyde. In this part, headspace gas chromatography with flame ionization detector (HS-GC-FID) and solid phase microextraction (SPME)-gas chromatography with mass spectrometric detectors (GC-MSD) had been used. In this report, we reported two fatal intoxication cases of ACH and FCH; one person was killed by his wife by poisoning his food and the other was suicide by poison. Two real cases of ACH and FCH in human blood and gastric contents have been analyzed by using the above-mentioned method. The Prussian blue reaction was positive in the two cases. The peaks of acetone with retention times of 0.998 min appear in specimens of the deceased are consistent with the retention times of pure acetone. The peaks of formaldehyde with a retention time of 1.658 min appear in heart blood of the deceased, and the retention time of formaldehyde of the liquid is 1.674 min, which are consistent with the retention times of pure formaldehyde (1.673 min). PMID:27026650

  15. Outbreaks of Short-Incubation Ocular and Respiratory Illness Following Exposure to Indoor Swimming Pools

    Science.gov (United States)

    Bowen, Anna B.; Kile, James C.; Otto, Charles; Kazerouni, Neely; Austin, Connie; Blount, Benjamin C.; Wong, Hong-Nei; Beach, Michael J.; Fry, Alicia M.

    2007-01-01

    Objectives Chlorination destroys pathogens in swimming pool water, but by-products of chlorination can cause human illness. We investigated outbreaks of ocular and respiratory symptoms associated with chlorinated indoor swimming pools at two hotels. Measurements We interviewed registered guests and companions who stayed at hotels X and Y within 2 days of outbreak onset. We performed bivariate and stratified analyses, calculated relative risks (RR), and conducted environmental investigations of indoor pool areas. Results Of 77 guests at hotel X, 47 (61%) completed questionnaires. Among persons exposed to the indoor pool area, 22 (71%) of 31 developed ocular symptoms [RR = 24; 95% confidence interval (CI), 1.5–370], and 14 (45%) developed respiratory symptoms (RR = 6.8; 95% CI, 1.0–47) with a median duration of 10 hr (0.25–24 hr). We interviewed 30 (39%) of 77 registered persons and 59 unregistered companions at hotel Y. Among persons exposed to the indoor pool area, 41 (59%) of 69 developed ocular symptoms (RR = 24; 95% CI, 1.5–370), and 28 (41%) developed respiratory symptoms (RR = 17; 95% CI, 1.1–260) with a median duration of 2.5 hr (2 min–14 days). Four persons sought medical care. During the outbreak, the hotel X’s ventilation system malfunctioned. Appropriate water and air samples were not available for laboratory analysis. Conclusions and relevance to professional practice Indoor pool areas were associated with illness in these outbreaks. A large proportion of bathers were affected; symptoms were consistent with chloramine exposure and were sometimes severe. Improved staff training, pool maintenance, and pool area ventilation could prevent future outbreaks. PMID:17384776

  16. N-Chlorotaurine and ammonium chloride: an antiseptic preparation with strong bactericidal activity.

    Science.gov (United States)

    Gottardi, Waldemar; Arnitz, Roland; Nagl, Markus

    2007-04-20

    The bactericidal activity of the endogenous antiseptic N-chlorotaurine (NCT) is significantly enhanced in the presence of ammonium chloride which induces the formation of monochloramine (NH(2)Cl) whose strong bactericidal activity is well known. In this study the properties of NCT plus ammonium chloride have been investigated. The reaction of active chlorine compounds like chloramine-T (N-chlorotoluene-sulfonamide sodium), chloroisocyanuric acid derivatives, hypochlorites (NaOCl, CaOCl(2)) with ammonium chloride did not stop at the stage of monochloramine, and the pungent smelling by-products di- and trichloramine, NHCl(2) and NCl(3), were also formed. This was not the case with NCT where only monochloramine was generated. The equilibrium constant of the reaction of NCT with ammonium was found to be [Formula: see text] , which allows to estimate the equilibrium concentration of monochloramine in aqueous solutions of NCT and ammonium chloride. At concentrations each ranging between 0.01% and 1.0% it comes to [NH(2)Cl]=3.5-254 ppm. As an unexpected result the monochloramine containing formulation turned out to be most stable in plain water without buffer additives. Quantitative killing assays revealed complete inactivation of 10(6) to 10(7)CFU/mL of seven bacterial strains by 0.1% NCT plus 0.1% ammonium chloride within 5 min, while with plain 0.1% NCT an incubation time of 2-4h was needed to achieve the same effect. The highly significant increase of bactericidal activity (200-300-fold) could be assigned to the presence of monochloramine which could be isolated by vacuum distillation. Aqueous solutions of NCT and ammonium chloride provide a highly effective and well tolerable antiseptic preparation appropriate to a treatment cycle of at least 1 month if stored in the refrigerator.

  17. Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Segura, Sergi, E-mail: sergigarcia@ub.edu [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia); Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Keller, Jürg [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia); Brillas, Enric [Laboratori d’Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Radjenovic, Jelena, E-mail: j.radjenovic@awmc.uq.edu.au [Advanced Water Management Centre, The University of Queensland, Level 4, Gehrmann Bld. (60), St Lucia, QLD 072 (Australia)

    2015-02-11

    Graphical abstract: - Highlights: • Mineralization of secondary effluent by anodic oxidation with BDD anode. • Complete removal of 29 pharmaceuticals and pesticides at trace level concentrations. • Organochlorine and organobromine byproducts were formed at low μM concentrations. • Chlorine species evolution assessed to evaluate the anodic oxidation applicability. - Abstract: Electrochemical advanced oxidation processes (EAOPs) have been widely investigated as promising technologies to remove trace organic contaminants from water, but have rarely been used for the treatment of real waste streams. Anodic oxidation with a boron-doped diamond (BDD) anode was applied for the treatment of secondary effluent from a municipal sewage treatment plant containing 29 target pharmaceuticals and pesticides. The effectiveness of the treatment was assessed from the contaminants decay, dissolved organic carbon and chemical oxygen demand removal. The effect of applied current and pH was evaluated. Almost complete mineralization of effluent organic matter and trace contaminants can be obtained by this EAOP primarily due to the action of hydroxyl radicals formed at the BDD surface. The oxidation of Cl{sup −} ions present in the wastewater at the BDD anode gave rise to active chlorine species (Cl{sub 2}/HClO/ClO{sup −}), which are competitive oxidizing agents yielding chloramines and organohalogen byproducts, quantified as adsorbable organic halogen. However, further anodic oxidation of HClO/ClO{sup −} species led to the production of ClO{sub 3}{sup −} and ClO{sub 4}{sup −} ions. The formation of these species hampers the application as a single-stage tertiary treatment, but posterior cathodic reduction of chlorate and perchlorate species may reduce the risks associated to their presence in the environment.

  18. New bisphosphonate labeled with Iodine-131 for the palliative therapy for bone metastases pain

    International Nuclear Information System (INIS)

    The aim of this work was to obtain new bisphosphonate marked with 131I suitable for palliative treatment of bone metastases pain characteristics. Materials and Methods: It started with aromatic amino acids and the synthesis consisted of three stages: 1) Protection of amino groups by acetylation; 2) phosphonation protected amino acids with a mixture of phosphorous acid and phosphorus pentachloride; 3) Lack of protection of the amino groups by basic hydrolysis. The compounds obtained were characterized by IR, 1H NMR, RMN13-C mass. Los spectrometry bisphosphonic acids obtained were labeled with 131I using chloramine T and iodogen as oxidants. Stability of labeled compounds in aqueous solution was studied serum. 3 mg of 2-amino-3- (4-hydroxyphenyl) -1-hydroxypropyl-1,1-bisphosphonic acid labeled of 131I were administered to male wistar rats (170-190 g) through a lateral tail vein. The scintigraphic study was conducted at 2, 6 and 12 hours. Results: The yield of the reactions of the amino group protection four compounds ranged from 75 to 80%, while the phosphonation was between 50 and 60%. The radiochemical purity of 2-amino-3- (4-hydroxyphenyl) -1-hydroxypropyl-1,1- bisphosphonic acid labeled with 131I was (91.5 ± 1.4)% and its stability was satisfactory for 72h. Scintigraphic images suggest excretion by the kidneys of the compound and from 12 h post-administration begin to visualize bone structures of the animal, suggesting that the compound exhibits affinity for these tissues. Conclusions: A novel synthesis method with modifications that yielded the sodium salts of bisphosphonic acids starting from the respective aromatic amino acids was developed. 2-amino-3- (4-hydroxyphenyl) -1-hydroxypropyl-1,1-bisphosphonic acid 131I labeled was stable up to 72h and showed affinity for bone tissue. (author)

  19. Disinfection by-products and microbial contamination in the treatment of pool water with granular activated carbon.

    Science.gov (United States)

    Uhl, W; Hartmann, C

    2005-01-01

    For swimming pools, it is generally agreed that free chlorine levels have to be maintained to guarantee adequate disinfection. Recommended free chlorine levels can vary between 0.3 and 0.6 mg/L in Germany and up to 3 mg/L in other countries. Bathers introduce considerable amounts of organic matter, mainly in the form of such as urine and sweat, into the pool water. As a consequence, disinfection byproducts (DBPs) are formed. Regulations in Germany recommend levels of combined chlorine of less than 0.2 mg/L and levels of trihalomethanes (THMs) of less than 20 microg/L. Haloacetic acids (HAAs), haloacetonitriles (HANs), chloropicrin and chloral hydrate are also detected in considerable amounts. However, these compounds are not regulated yet. Swimming pool staff and swimmers, especially athletes, are primarily exposed to these byproducts by inhalation and/or dermal uptake. In Germany, new regulations for swimming pool water treatment generally require the use of activated carbon. In this project, three different types of granular activated carbon (GAC) (one standard GAC, two catalytic GACs) are compared for their long time behaviour in pool water treatment. In a pilot plant operated with real swimming pool water, production and removal of disinfection byproducts (THMs, HAAs, AOXs), of biodegradable substances (AOC), of bacteria (Pseudomonas aeruginosa, Legionella, coliforms, HPC) as well as the removal of chlorine and chloramines are monitored as function of GAC bed depth. Combined chlorine penetrates deeper in the filter bed than free chlorine does. However, both, free and combined chlorine removal efficiencies decrease over the time of filter operation. The decreases of removal efficiencies are also observed for parameters such as dissolved organic carbon, spectral absorption coefficient, adsorbable organic carbon and most of the disinfection byproducts. However, THMs, especially chloroform are produced in the filter bed. The GAC beds were contaminated microbially

  20. Preparation of monoclonal antibodies against cardiac myosin and some radiolabelling studies

    International Nuclear Information System (INIS)

    Monoclonal antibodies were raised against myosin, a specific indicator of myocardial infarction and labelled with 125I and 99mTc. Human cardiac myosin was isolated from normal human heart and was used for raising the monoclonal antibodies by the hybridoma technique. Antibody producing clones were identified by ELISA and cloning was done by the limiting dilution technique. Of the 13 clones obtained, 4 were deemed suitable for further studies. The antibodies were grown in ascites, purified, isotyped and their cross reactions with other forms of myosin were estimated. All the clones showed negligible cross reaction with rabbit myosin, but reacted to different extents with bovine skeletal myosin. The most avid antibody Mab-4G4 was chosen for further labelling studies. Mab-4G4 was labelled with 125I using different oxidising agents such as iodogen, chloramine-T and lactoperoxidase. Purified radioiodinated antibody with radiochemical purity >95% could be obtained by gel filtration. Immunoreactivity was retained as tested by binding to myosin immobilised on a solid support. Mab-4G4 was also labelled with 99mTc using stannous tartrate as the reducing agent. Radiolabelling yield was ∼60%, the purity was >95% and the immunoreactivity was retained. Both the labelled preparations were tested for bio-distribution in normal and infarcted rats. The activity accumulation in the infarcted region was ∼ 1.5 and 3.5 times as that in normal heart muscle for 125I and 99mTc labelled Mab-4G4 respectively. The major problem with the iodinated antibody was the in vivo deiodination resulting in very high percentage of activity in the thyroid. Although the fraction of the total activity associated with the infarcted heart is not very impressive, the fact that the activities with the infarcted and normal hearths are significantly different is heartening. With further optimisation of labelling and use of F(ab)'2 fragments, better delineation of the infarct sites is aspired. (author)

  1. Health effects of disinfection by-products in chlorinated swimming pools.

    Science.gov (United States)

    Florentin, Arnaud; Hautemanière, Alexis; Hartemann, Philippe

    2011-11-01

    Increased attendance at swimming pools is correlated with higher input of organic and minerals pollutants introduced by swimmers in the swimming pool water. In most swimming pools, microbiological control is performed by disinfection with the addition of chlorine. Chlorine is now well-known to lead to the formation of many disinfection by-products (DBPs) including trihalomethanes and chloramines. The hypothesis of a link between the presence of eye and skin irritation syndromes in swimmers and contact with swimming pool water treated with chlorine was initially proposed by Mood (1953). During recent decades many epidemiological studies have described the importance of DBPs generated with natural or imported organic matter present in water. Many of these DBPs are suspected to be toxic or even carcinogenic. Trihalomethanes and haloacetic acid families are the most studied but others DBPs, like chloral hydrate, haloacetonitriles, N-nitrosodimethylamine and the bromate ion, are emerging compounds of interest. Epidemiological data about the risk of cancer are still controversial. However, numerous publications highlight a toxic risk especially the risk of allergy and respiratory symptoms for babies and elite swimmers. The few publications dedicated to risk assessment do not suggest increased risk, other than for elite swimmers. These publications are likely to underestimate the risk associated with DBPs because of the lack of data in the literature precludes the calculation of risk associated with certain compounds or certain pathways. Thus for regulations, the need to take into account the risks associated with disinfection by-products is now important without forgetting the need of the control of microbiological hazards in swimming pools. PMID:21885333

  2. The development of a human calcitonin radioimunoassay, with 'in house' reagent production, for application to the early diagnosis of medullary thyroid carcioma

    International Nuclear Information System (INIS)

    Reagent production for human Calcitonin (hCT) Radioimmunoassay (RIA) was carried out in our laboratory starting from a kind donation of human synthetic preparation from CIBA (Basel, Switzerland). This product was used for anti-hCT antibody production in rabbits and guinea-pigs and for radioiodination, according to two different methods: classical and stoichiometric Chloramine T techniques. The use of Sephadex G-50 in tracer purification allowed the obtainement of 125I-hCT free of high molecular weight contaminats. A repurification on polyacrylamide gel electrophoresis provided 125I-hCT of higher specific activity that presented specific binginds, to good quality antisera, of the same order of imported tracers (∼ 45%). Different antisera were obtained in rabbits and quinea-pigs, but only one (GP2-IPEN) could be used in such a dilution (1:4000) to provide highly sensitive curves (minimal detectable concentration < 70 pg/ml) presenting, however, very low specific bindings (7-10%). For this reason, in order to be able to set up a regular quality control of our hCT-RIA technique, an antiserum kindly donated by the Karolinska Institute (Stockholm, Sweden) was used. This way, through the use of an higher antibody dilution (1:8000), higher specific bindings (20-30%), higher sensitivies (< 30 pg/ml) and satisfactory precision were obtained. We consider this study a first approach to a complete national production of hCT-RIA reagents, that, at present moment, depends practically only from the obtainement of a high avidity anti-hCT antiserum. More has to be done on accuracy and correct clinical application of this assay to the screening of the familial form of Medullary Thyroid Carcinoma. We also emphasize the fact, due to our limited financial possibilities, all the work was carried out with great economy, taking advantage of previously set up techniques and of the experience already acquired in this field of work. (author)

  3. Synthesis and enantiomeric evaluation of radiolabelled methyl phenidate for the study of dopamine reuptake sites

    International Nuclear Information System (INIS)

    Full text: Neurological diseases such as Parkinson's Disease and associated Movement Disorders have been characterised by reductions in the number of dopamine re-uptake sites or dopamine transporters (DAT) on presynaptic neurons in the striatum. Radiolabelled drugs which display specific and selective binding to the DAT has thus found clinical utility in medical imaging. The psychomotor stimulant methyl phenidate (MP) or Ritalin 1 and several derivatives have demonstrated high affinity binding to these DAT where they exert their pharmacological action. MP possesses two chiral centers with its pharmacological activity being attributed to the dl-threo diastereomer, the dl-erythro being inactive. Furthermore, imaging studies using Positron Emission Tomography (PET) with carbon-11 radiolabelled MP confirmed the d-threo enantiomer to be most active. In vitro studies indicate that compounds substituted with either bromine or iodine in the 3 position of the aromatic ring exhibit high affinity and selective binding to DAT and were thus targeted for radiolabelling with both the PET tracer Bromine-76 as well as the SPECT tracer lodione-123. Threo methyl phenidate and its halogenated derivatives were prepared by the condensation of 3-bromophenylacetonitrile and 2-bromopyridine according to modified literature methods. Radiohalogenation with either 76Br or 123I was achieved by halodestannylation reactions of the corresponding tributyl stannane precursor in the presence of chloramine-T as the oxidant. Purification by C-18 reverse phase HPLC gave the dl-threo product in 70-80% radiochemical yield and in greater than 95% radiochemical purity. Separation of the d and / enantiomers was achieved by chiral HPLC. Biodistribution studies in rodents indicated high uptake of radioactivity in tissues with known DAT sites. PET and SPECT imaging studies in primates indicated high uptake in the striatum compared to the cerebellum reference tissue. The synthesis, diastereomeric separation

  4. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    International Nuclear Information System (INIS)

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to be found in swimming pool water: chloroform, bromodichloromethane, dibromochloromethane, bromoform, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetronitrile, trichloroacetonitrile, trichloronitromethane, dichloropropanone, trichloropropanone, and chloral hydrate. First order photolysis constants ranged 26-fold from 0.020 min−1 for chloroform to 0.523 min−1 for trichloronitromethane. The rate constants generally increased with bromine substitution. Using the UV removal of combined chlorine as an actinometer, the rate constants were recalculated to actual treatment doses of UV applied in a swimming pool. In an investigated public pool the UV dose was equivalent to an applied electrical energy of 1.34 kWh m−3 d−1 and the UV dose required to removed 90% of trichloronitromethane was 0.4 kWh m−3 d−1, while 2.6 kWh m−3 d−1 was required for chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes ranged from 0.6 to 3.1 kWh m−3 d−1. It was predicted thus that a beneficial side-effect of applying UV for removing combined chlorine from the pool water could be a significant removal of trichloronitromethane, chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes. - Highlights: ► UV irradiation is able to degrade all 12 investigated disinfection by-products. ► Bromine species are easier to remove than their chlorinated analogues. ► UV dose used for combined chlorine was comparable with doses required for DBP removal. ► Significant removal of some disinfection by-products in swimming pools is indicated

  5. 原料奶粉及乳饮料中L-羟脯氨酸的含量测定%Determination of L-hydroxyproline in raw milk powder and milk drink

    Institute of Scientific and Technical Information of China (English)

    陈铭中; 钟旭美; 胡洪森

    2011-01-01

    The method of P-dimethylaminobenzaldehyde spectrophotom etry was used to determine L-hydroxyproline in raw milk powder and milk drink.The result was stable and the recovery rate was high.After hydrolyzed with acid,L-hydroxyproline was released and oxidized by chloramine T.L-hydroxyproline oxide reacted with P-dimethylaminobenzaldehyde and formed red compounds,the absorbance was detected at 580 nm.The method was simple and accurate.Compared with other detecting methods,the expense of it was smaller.It could provide reference for enterprises to detect whether product was adulterated hydrolyzed protein in raw milk powder and milk drink.%采用对二甲氨基苯甲醛分光光度法测定奶粉及乳饮料中L-羟脯氨酸,具有较好的稳定性。奶粉及乳饮料经浓盐酸水解,得到的L-羟脯氨酸经过氯胺T氧化,与对二甲氨基苯甲醛反应生成红色物质,在558nm下测定吸光值。该方法操作简单、准确率高、检测费用相对少,可用于企业奶粉原料掺水解蛋白及产品中是否掺有水解蛋白的检测提供依据。

  6. Identification of the binding subunit of the D/sub 1/-dopamine receptor by photoaffinity crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Amlaiky, N.; Berger, J.G.; Chang, W.; McQuade, R.D.; Caron, M.G.

    1986-03-01

    A derivative of the potent D/sub 1/ antagonist SCH-23390 has been synthesized. This compound, (R,S)-1-(m-aminophenyl)-7-chloro-8-hydroxy-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH-38548), has been radioiodinated by a chloramine T procedure yielding 3 radioiodinated products. One of these separated isomers (R/sub f/ = 0.35; CH/sub 2/Cl/sub 2/:MEOH:TEA; 82.5:17.5:0.1 on TLC) binds reversibly to rat striatal membranes with high affinity (K/sub D/ approx. 80 pM) appropriate stereoselectivity and D/sub 1/-dopaminergic specificity. (/sup 125/I)SCH-38548 can be covalently incorporated into a peptide of M/sub r/ approx. 72,000 using the heterobifunctional crosslinking reagent N-succinimidyl-6-(4'-azido-2'-nitro-phenylamino) hexanoate. Covalent incorporation of (/sup 125/I) SCH-38548 into the M/sub r/ approx. 72,000 peptide can be blocked by dopaminergic agents with D/sub 1/-dopaminergic specificity (for agonists: SKF 38393 > apomorphine > dopamine; for antagonists: SCH-23390 > cis-flupentixol >>> trans-flupentixol). The D/sub 1/-dopaminergic selectivity and specificity of the labeling was further demonstrated by the fact that other antagonists such as domperidone, ketanserin, phentolamine and alprenolol did not compete for the covalent labeling of the M/sub r/ approx. 72,000 peptide. This new radioligand should be useful in the molecular characterization of the D/sub 1/-dopaminergic receptor from various sources.

  7. Removal of organic contaminants from secondary effluent by anodic oxidation with a boron-doped diamond anode as tertiary treatment

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Mineralization of secondary effluent by anodic oxidation with BDD anode. • Complete removal of 29 pharmaceuticals and pesticides at trace level concentrations. • Organochlorine and organobromine byproducts were formed at low μM concentrations. • Chlorine species evolution assessed to evaluate the anodic oxidation applicability. - Abstract: Electrochemical advanced oxidation processes (EAOPs) have been widely investigated as promising technologies to remove trace organic contaminants from water, but have rarely been used for the treatment of real waste streams. Anodic oxidation with a boron-doped diamond (BDD) anode was applied for the treatment of secondary effluent from a municipal sewage treatment plant containing 29 target pharmaceuticals and pesticides. The effectiveness of the treatment was assessed from the contaminants decay, dissolved organic carbon and chemical oxygen demand removal. The effect of applied current and pH was evaluated. Almost complete mineralization of effluent organic matter and trace contaminants can be obtained by this EAOP primarily due to the action of hydroxyl radicals formed at the BDD surface. The oxidation of Cl− ions present in the wastewater at the BDD anode gave rise to active chlorine species (Cl2/HClO/ClO−), which are competitive oxidizing agents yielding chloramines and organohalogen byproducts, quantified as adsorbable organic halogen. However, further anodic oxidation of HClO/ClO− species led to the production of ClO3− and ClO4− ions. The formation of these species hampers the application as a single-stage tertiary treatment, but posterior cathodic reduction of chlorate and perchlorate species may reduce the risks associated to their presence in the environment

  8. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of Co60

    International Nuclear Information System (INIS)

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms, leading to a spastic paralysis of hind limbs in mice. The objective was to carry out biochemical and pharmacological studies of native and irradiated crotamine with Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 m NaCl with 2.0 kGy gamma radiation emitted by a Co source. Native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD50), and biodistribution. The native and irradiated crotamine were labeled with 29.6 MBq of I using chloramine T method and separated in a Sephadex G-50 column. Male Swiss mice (35 @ 5 g) were injected IP with 0.1 mL (2.4x10 cpm/mouse) of I native crotamine or with 0.4 mL (1.3 x 10 cpm/mouse) of I irradiated crotamine. The animals were sacrificed by ether inhalation at 0.08, 0.25, 0.5,1, 2, 3, 4, 8, 12, and 24 hours. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change protein concentration, electrophoretic profile, or protein primary structure, although differences could be seen by spectroscopic techniques. Gamma radiation reduced crotamine toxicity, but did not eliminate bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. Native and irradiated crotamine have an affinity to skeletal muscle and did not cross the blood-brain barrier. (author)

  9. A retrospective study of disease in elasmobranchs.

    Science.gov (United States)

    Garner, M M

    2013-05-01

    This report reviews diseases of 1546 elasmobranchs representing at least 60 species submitted to Northwest ZooPath from 1994 to 2010. Cownose rays (Rhinoptera bonasus) (78), southern rays (Dasyatis americana) (75), dusky smooth-hounds (Mustelus canis) (74), bonnethead sharks (Sphyrna tiburo) (66), and bamboo sharks (Hemiscylliidae) (56) were the most commonly submitted species. Infectious/inflammatory disease was most common (33.5%) followed by nutritional (11.9%, mostly emaciation), traumatic (11.3%), cardiovascular (5.5%, mostly shock), and toxin-associated disease (3.7%). Bacterial infections (518/1546, 15%) included sepsis (136/518, 26%), dermatitis (7%), branchitis (6%), and enteritis (4%). Fungal infections (10/1546, 0.6%) included dermatitis (30%), hepatitis (30%), and branchitis (20%). Viral or suspected viral infections or disease processes (15/1546, 1%) included papillomatosis (47%), herpesvirus (20%), and adenovirus (7%). Parasitic infections (137/1546, 9%) included nematodiasis (36/137, 26%), ciliate infections (23%), trematodiasis (20%), coccidiosis (6%), myxozoanosis (5%), amoebiasis (4%), cestodiasis (1%), and flagellate infections (1%). Inflammation of unknown cause (401/1546, 26%) included enteritis (55/401, 14%), branchitis (9%), encephalitis (9%), and dermatitis (7%). Traumatic diseases (174/1546, 11.3%) included skin trauma (103/174, 60%), stress/maladaptation (9%), and gut trauma (7%). Toxicoses (57/1546, 4%) included toxic gill disease (16/57, 26%), gas bubble disease (19%), fenbendazole (7%), ammonia (7%), chlorine (5%), and chloramine (3%). Species trends included visceral nematodiasis in black-nosed sharks (Carcharhinus acronotus) (55%); sepsis in dusky smooth-hounds (41%), blue-spotted stingrays (36%), southern rays (36%), and wobeggong sharks (Orectolobus spp) (69%); emaciation in bamboo (33%) and bonnethead (32%) sharks and freshwater stingrays (Potamotrygon motoro) (32%); and trauma in bonnethead sharks (30%). PMID:23528944

  10. Exhaled nitric oxide and airway hyperresponsiveness in workers: a preliminary study in lifeguards

    Directory of Open Access Journals (Sweden)

    Massin Nicole

    2009-12-01

    Full Text Available Abstract Background Airway inflammation and airway hyperresponsiveness (AHR are two characteristic features of asthma. Fractional exhaled nitric oxide (FENO has shown good correlation with AHR in asthmatics. Less information is available about FENO as a marker of inflammation from work exposures. We thus examined the relation between FENO and AHR in lifeguards undergoing exposure to chloramines in indoor pools. Methods 39 lifeguards at six indoor pools were given a respiratory health questionnaire, FENO measurements, spirometry, and a methacholine bronchial challenge (MBC test. Subjects were labeled MBC+ if the forced expiratory volume (FEV1 fell by 20% or more. The normalized linear dose-response slope (NDRS was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given. The relation between MBC and FENO was assessed using logistic regression adjusting on confounding factors. The association between NDRS and log-transformed values of FENO was tested in a multiple linear regression model. Results The prevalence of lifeguards MBC+ was 37.5%. In reactors, the median FENO was 18.9 ppb (90% of the predicted value vs. 12.5 ppb (73% predicted in non-reactors. FENO values ≥ 60% of predicted values were 80% sensitive and 42% specific to identify subjects MBC+. In the logistic regression model no other factor had an effect on MBC after adjusting for FENO. In the linear regression model, NDRS was significantly predicted by log FENO. Conclusions In lifeguards working in indoor swimming pools, elevated FENO levels are associated with increased airway responsiveness.

  11. Therapeutic efficacy of intralesional 131I-labelled hyaluronectin in grafted human glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Girard, N.; Courel, M.N.; Vera, P.; Delpech, B. [Centre Henri-Becquerel, Rouen (France). Laboratoire d' Oncologie Moleculaire

    2000-07-01

    The grafted human glioblastoma cell CB109 was used as a model for intralesional therapy with 131I-labelled hyaluronectin glycoprotein (131I-HN). 131I-HN bound specifically to in situ hyaluronic acid (HA), a main component of the extracellular matrix which is involved in tumour invasion. Labelling experimental conditions were determined and, finally, 25 {mu}Ci/{mu}gHN, 1 {mu}g chloramine-T/{mu}gHN and a 60-s stirring period provided a 131I-HN preparation with an optimal affinity for HA (64% compared to unlabelled HN). Following intratumoral injection, 131I-HN was retained with a limited diffusion outside the tumour. On day 4 the radioactivity concentrated in the tumour was still 25 times greater than that in the liver, spleen and kidneys combined. For therapeutic assays, 65 {mu}Ci 131I-HN was injected into the tumour, resulting in a delivery of 6.8 Gy over a 7-day period. Controls received unlabelled HN, heat-inactivated HN, a mixture of inactivated HN plus free 131I or no treatment (six animals per group). Tumour volumes were evaluated every second day from treatment day and the rate of tumour growth was expressed as a ratio of tumour size at time intervals to the tumour size at the time of injection. Growth curves were compared: heat-inactivated with or without free 131I had no anti-tumour effect. Unlabelled HN-injected tumours had a slightly slower growth rate than untreated tumours (p < 0.02) and growth rate of 131I-HN-injected tumours was much lower (p < 0.00002). A pronounced inhibitory effect with intralesional 131I-labelled HN injection resulted from a combination of a) blockage of HA, a proliferation facilitating factor, and b) local irradiation of tumoral tissue, while uptake in normal tissues was minimized.

  12. Harvard--MIT research program in short-lived radiopharmaceuticals

    International Nuclear Information System (INIS)

    This report describes progress on five projects. The first project showed a 1000 fold concentration of the cationic complex 99mTc (MIBI) in heart cell mitochondria vs heart cell cytoplasm, as determined by high resolution electron probe microanalysis. Additional technetium-99m based complexes are being developed and tested. The second project involves evaluating technetium acetylacteonates as potential indicators of cerebral blood flow. An intermediate in the synthesis of a technetium porphyrin complex has been synthesized; an oxotechnetium(V)-2,4-pentanedione complex has been prepared and is currently being characterized. The third project involves using radio labelled antibodies for diagnosis and treatment of cancer. An early discovery was that chloramine-T based iodination protocols resulted in a reversal of the charge on mouse lgGs. Immunoperoxidase-labelled monoclonal antibody MOv 18 was shown to bind specifically to the most frequent ovarian aderon carcinomas, and not to healthy tissue, making this antibody a good candidate for immunotherapy or immunodetection. Work on a specific immunotherapy protocol suffered a setback when one reagent, a 125I-biotin complex, proved to be unstable in vivo. The fourth project involves labelling antibodies with positron emitting radionuclides. Radiofluorination was accomplished through reductive alkylation of 18F-aldehyde, or pentafluorophenyl esters. Radioiodination was accomplished using alkyl-tin derivation exchange. The fifth project examined antibody modification for use in radioimmune imaging. Technetium-99m-labelled lgG was shown to be biologically equivalent to Indium-III-labelled lgG for imaging focal sites of inflamation. Also, Indium III labelling of small bioactive peptides was examined as a means of imaging important physiological processes. 44 refs., 2 figs

  13. Radioimmunotherapy in refractory b-cell nonhodgkins lymphoma with I-131-labeled chimeric anti cd-20 c2b8 (I-131 rituximab): preliminary result

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hye Jin; Park, Yeon Hee; Kim, Sung Eun and others [Korea University Medical School, Seoul (Korea, Republic of)

    2005-07-01

    Recently, the native chimeric human-mouse anti CD-20 antibody IDEC-C2B8 (Rituximab) has been widely applied in NHL. This ongoing phase study was to evaluate whether radioimmunotherapy (RIT) with I-131 rituximab is effective in refractory B-cell NHL. Inclusion criteria were as follows: B-cell NHL with relapsed or refractory to primary standard therapy, measurable disease, adequate hematologic, renal, and hepatic function, informed consent. The rituximab (Mabthera, Roach) was radiolabeled with iodine-131(I-131) using a modified chloramine T method with high radiochemical purity (95%) and preservation of immuno-reactivity. All patients received loading doses of unlabeled rituximab (median, 40 mg: range, 20{approx}70 mg) immediately prior to administration of therapeutic dose (51.4{approx}152.2 MBq/kg), and then underwent gamma camera scan. 11 patients were enrolled (4 low-grade B-cell NHL, 7 DLBCL, median age 63 years). Patients had received a median of three prior chemotherapy regimens. The objective response rate was 36.4% (1 CR, 3 PRs). These all responses were observed in low-grade B-cell NHL, except one with DLBCL. Adverse events were primarily hematologic toxicities; the incidence of grade 3/4 neutropenia, thrombocytopenia, and anemia was 27.3%, 45.5%, and 18.2%, respectively. The treatment-related mortality was observed in one patient, who had been previously treated with high-dose chemotherapy plus TBI with autologous stem cell transplantation. RIT with I-131 rituximab seems to be effective tolerable in refractory low-grade B-cell NHL, although modest activity in refractory DLBCL. Further studies to define the efficacy of I-131 rituximab in DLBCL are warranted.

  14. Transformation of acetaminophen during water chlorination treatment: kinetics and transformation products identification.

    Science.gov (United States)

    Cao, Fei; Zhang, Mengtao; Yuan, Shoujun; Feng, Jingwei; Wang, Qiquan; Wang, Wei; Hu, Zhenhu

    2016-06-01

    As a high-consumption drug in the world, acetaminophen (AAP) has been widely detected in natural waters and wastewaters. Its reactivity and the transformation products formed during chlorination may greatly threaten the safety of drinking water. The reaction kinetics of AAP during chlorination was investigated in this study. The results showed that the reaction kinetics could be well described with a kinetics model of -d[AAP]/dt = k app[AAP]t (0.63)[Cl2]t (1.37). The values of apparent rate constant (k app) were dependent on reaction temperature, ammonium, and pH. With the increase in reaction temperature from 5.0 ± 1.0 to 40.0 ± 1.0 °C, the removal efficiency of AAP increased from 60 to 100 %. When ammonium was present in the solution at 2.0 mg/L, the transformation of AAP was inhibited due to the rapid formation of chloramines. The maximum of k app was 0.58 × 10(2) M(-1) · min(-1) at pH 9.0, and the minimum was 0.27 M(-1) · min(-1) at pH 11.0. A low mineralization of AAP (about 7.2 %) with chlorination was observed through TOC analysis, implying the formation of plenty of transformation products during chlorination. The main transformation products, hydroquinone and two kinds of chlorinated compounds, monochlorinated acetaminophen and dichlorinated acetaminophen, were detected in gas chromatography-mass spectrometry analysis.

  15. Removal of geosmin and 2-methylisoborneol by biological filtration.

    Science.gov (United States)

    Elhadi, S L N; Huck, P M; Slawson, R M

    2004-01-01

    The quality of drinking water is sometimes diminished by the presence of certain compounds that can impart particular tastes or odours. One of the most common and problematic types of taste and odour is the earthy/musty odour produced by geosmin (trans-1, 10-dimethyl-trans-9-decalol) and MIB (2-methylisoborneol). Taste and odour treatment processes including powdered activated carbon, and oxidation using chlorine, chloramines, potassium permanganate, and sometimes even ozone are largely ineffective for reducing these compounds to below their odour threshold concentration levels. Ozonation followed by biological filtration, however, has the potential to provide effective treatment. Ozone provides partial removal of geosmin and MIB but also creates other compounds more amenable to biodegradation and potentially undesirable biological instability. Subsequent biofiltration can remove residual geosmin and MIB in addition to removing these other biodegradable compounds. Bench scale experiments were conducted using two parallel filter columns containing fresh and exhausted granular activated carbon (GAC) media and sand. Source water consisted of dechlorinated tap water to which geosmin and MIB were added, as well as, a cocktail of easily biodegradable organic matter (i.e. typical ozonation by-products) in order to simulate water that had been subjected to ozonation prior to filtration. Using fresh GAC, total removals of geosmin ranged from 76 to 100% and total MIB removals ranged from 47% to 100%. The exhausted GAC initially removed less geosmin and MIB but removals increased over time. Overall the results of these experiments are encouraging for the use of biofiltration following ozonation as a means of geosmin and MIB removal. These results provide important information with respect to the role biofilters play during their startup phase in the reduction of these particular compounds. In addition, the results demonstrate the potential biofilters have in responding to

  16. Kinetics of Chlorination of Benzophenone-3 in the Presence of Bromide and Ammonia.

    Science.gov (United States)

    Abdallah, Pamela; Deborde, Marie; Dossier Berne, Florence; Karpel Vel Leitner, Nathalie

    2015-12-15

    The aim of this study was to assess the impact of chlorination on the degradation of one of the most commonly used UV filters (benzophenone-3 (BP-3)) and the effects of bromide and ammonia on the kinetics of BP-3 elimination. Bromide and ammonia are rapidly converted to bromine and chloramines during chlorination. At first, the rate constants of chlorine, bromine and monochloramine with BP-3 were determined at various pH levels. BP-3 was found to react rapidly with chlorine and bromine, with values of apparent second order rate constants equal to 1.25(±0.14) × 10(3) M(-1)·s(-1) and 4.04(±0.54) × 10(6) M(-1)·s(-1) at pH 8.5 for kChlorine/BP-3 and kBromine/BP-3, respectively, whereas low monochloramine reactivity was observed (kNH2Cl/BP-3 = 0.112 M(-1)·s(-1)). To assess the impact of the inorganic content of water on BP-3 degradation, chlorination experiments with different added concentrations of bromide and/or ammonia were conducted. Under these conditions, BP-3 degradation was found to be enhanced in the presence of bromide due to the formation of bromine, whereas it was inhibited in the presence of ammonia. However, the results obtained were pH dependent. Finally, a kinetic model considering 18 reactions was developed using Copasi to estimate BP-3 degradation during chlorination in the presence of bromide and ammonia.

  17. Cut off values of laser fluorescence for different storage methods at different time intervals in comparison to frozen condition: A 1 year in vitro study

    Directory of Open Access Journals (Sweden)

    Rudra Kaul

    2014-01-01

    Full Text Available Aims: The aim of the following study is to evaluate the change in laser fluorescence (LF values for extracted teeth stored in different solutions over 1 year period, to give cut-off values for different storage media at different time intervals to get them at par with the in vivo conditions and to see which medium gives best results with the least change in LF values and while enhancing the validity of DIAGNOdent in research. Materials and Methods: Ninety extracted teeth selected, from a pool of frozen teeth, were divided into nine groups of 10 each. Specimens in Groups 1-8 were stored in 1% chloramine, 10% formalin, 10% buffered formalin, 0.02% thymol, 0.12% chlorhexidine, 3% sodium hypochlorite, a commercially available saliva substitute-Wet Mouth (ICPA Pharmaceuticals and normal saline respectively at 4°C. The last group was stored under frozen condition at −20°C without contact with any storage solution. DIAGNOdent was used to measure the change the LF values at day 30, 45, 60, 160 and 365. Statistical Analysis Used: The mean change in LF values in different storage mediums at different time intervals were compared using two-way ANOVA. Results: At the end of 1 year, significant decrease in fluorescence (P < 0.05 was observed in Groups 1-8. Maximum drop in LF values occurred between day 1 and 30. Group 9 (frozen specimens did not significantly change their fluorescence response. Conclusions: An inevitable change in LF takes place due to various storage media commonly used in dental research at different time intervals. The values obtained from our study can remove the bias caused by the storage media and the values of LF thus obtained can hence be conveniently extrapolated to the in vivo condition.

  18. Long-lived reactive species formed on proteins induce changes in protein and lipid turnover.

    Science.gov (United States)

    Davies, Michael

    2014-10-01

    Proteins are major targets for oxidative damage in vivo due to their high abundance and rapid rates of reaction with both one-electron (radical) and two-electron oxidants (e.g. singlet oxygen, hypochlorous acid, peroxynitrous acid, reactive aldehydes). The turnover of both native and modified proteins is critical for maintenance of cell homeostasis, with this occurring via multiple pathways including proteasomes (for cytosolic species), the Lon protease (in mitochondria), and the endo-lysosomal systems (both extra- and intra-cellular species). Evidence has been presented for both enhanced and diminished rates of catabolism of modified proteins, as well as altered turnover of native (unmodified) proteins as a result of damage to these systems, potentially as a result of the accumulation of damaged proteins. In recent studies we have shown that long-lived reactive species forms on proteins (hydroperoxides, chloramines and aldehydes) can modify the activity of proteasomal and lysosomal enzymes. Some of the above species are efficient inhibitors of the tryptic and chymotryptic activities of the 26S proteasome, as well as lysosomal cathepsin and acid lipase activities. These are key species in the turnover of both proteins and lipoproteins. The loss of enzyme activity is accompanied in many cases, by oxidation of critical thiol residues via molecular reactions. For reactive aldehydes (either free or protein-bound) direct enzyme inhibition can occur as well as modulation of protein levels and, in the case of lysosomes, changes in lysosomal numbers. Overall, these data indicate that the formation of reactive species on proteins can modulate cell function by multiple pathways including interference with the turnover of native proteins (including critical cell signalling molecules) and alterations in the rate of clearance of modified proteins. Both pathways may contribute to the development of a number of human pathologies associated with oxidative damage. PMID:26461411

  19. Relation between chlorine with the quality of crude water

    International Nuclear Information System (INIS)

    Chlorine as disinfection agent in drinking water was used widely since it was successfully been practiced in drinking water in Jersey City, 1908. Mostly, water treatment plants in Malaysia were using chlorine as disinfection agent to kill pathogen and contaminated materials that can be dangerous to consumer. Because of chlorine was a strongly disinfection agent, it also can react with another chemical components such as manganese, hydrogen, sulfides, ammonia and phenol in water. These reactions happen very fast, and chlorine will not react as disinfection agent unless all the organic and inorganic substitution presented in water reacts with chlorine. These reactions between components will increase demand of chlorine in water. The demand of chlorine in water must be filled before the free radical chlorine occurred. These free radical chlorine will decay into hypochlorous acid and hypochlorite ion that so important in disinfection process to kill pathogens and pollutants in water. Most of water treatment plant to maintain free chlorine up to 0.2 mg/ L in distribution system to consumer. These researches involved determination of parameters that can be trusted to react with the chlorine in nine sampling station along Semenyih River and four stations in water treatment plants. These parameters were determined from ammonia, cyanides, sulfides, phenol, phosphorus, nitrite, manganese, iron and sum of organic carbons. Overall, these researches concluded that ammonia and sum of organic carbons were the most compounds that react with the chlorine to produce tryhalometane and chloramines. Besides that, the concentration of cyanides compounds, sulfide, phenol, phosphorus, nitrite, manganese and iron also decrease after the chlorination process. Results can used to evaluate demanding levels of chlorine in Semenyih River. (author)

  20. Pharmacokinetics of Pegylated recombinant new human Interleukin-6 (PET-rhIL-6)

    International Nuclear Information System (INIS)

    In this study, the newly developed Pegylated recombinant human Interleukin-6 (PEG-rhIL-6) was investigated. With 125I labeled PEG-rhIL-6 by two-phase chloramine-T method. Thirty of the SD rats were randomly divided into 6 groups (group 1, 2, 3, 4, 5 and 6, respectively), with 5 animals (3 males and 2 females) each group. Group 1, 2 and 3 were injected subcutaneously with 125I-PEG-rhIL-6 at the dose of 40, 20 and 3 μg/kg, respectively. Group 4, 5 and 6 were injected intravenously with 125I-PEG-rhIL-6 with the same dose level, respectively. Blood samples were collected at different time intervals after injection. The plasma concentration (ng/ml) of 125I-PEG-rhIL-6 were determined by 125I isotope tracing method and then assessed with 3P87 software to obtain the pharmacokinetic parameters. Results clearly showed that 1/2 ke (20.41, 21.53, 19.77) and tl/2 ka (10.44, 11.26, 11.37) of group 1-3 are higher number than t1/2β (17.54, 18.78, 17.81) and t1/2α (1.93, 1.60, 1.78) of group 4-6. The pharmacological activity of 125I-PEG-rhIL-6 maintain longer time by subcutaneous injection; The pharmacokinetic of V/Fc after sc (694.96 ml/kg) is higher than those after iv (115.26 ml/kg), which showed that the excretion speed of 125-PEG-rhIL-6 given by sc was slowly. The above results obtained indicated that the pharmacokinetic characteristics of 125I-PEG-rhIL-6 would provide important information for clinical application and the subcutaneous injection is better. (authors)

  1. Role of the metabolism of parathyroid hormone

    International Nuclear Information System (INIS)

    The heterogeneity of parathyroid hormone (PTH) in plasma has prompted investigations of the metabolism of PTH and its relationship to hormone action. The time course of tissue distribution and metabolism of electrolytically iodinated PTH (E-PTH) previously shown to retain biological activity was compared with that of inactive PTH iodinated with Chloramine-T (CT-PTH). Labeled PTH (0.4 μg) was injected in the saphenous veins of anesthetized rats which were sacrificed at 1, 3, 5, 10, and 20 min. Tissue extracts from kidney, liver, and serum were chromatographed to separate intact PTH from its metabolites. In the kidney, the initial rate of degradation of E-PTH was greater than that of CT-PTH. The difference in initial rates of metabolism may be due, in part, to receptor-specific hydrolysis on peritubular cell membranes which selectively act on biologically active PTH molecules. PTH-responsive adenyl cyclase activity in isolated kidney cortex plasma membranes was measured and PTH metabolism was monitored simultaneously. When degradation was completely blocked by histone f3 (1 mg/ml), adenyl cyclase activity was significantly increased over control. In addition, when adenyl cyclase activity was negligible, the rate of PTH degradation by the membranes was not significantly diminished. Consistent with the in vivo data was the observation that E-PTH is metabolized by these membranes at a greater rate than CT-PTH. The data demonstrate the existence of a receptor-specific metabolism at sites which are independent of PTH receptor mediated adenyl cyclase activity

  2. Development of anti-CD30 radioimmunoconstructs (RICs) for treatment of Hodgkin's lymphoma. Studies with cell lines and animal studies

    International Nuclear Information System (INIS)

    Objectives: comparison of the binding affinity to a CD30-positive Hodgkin lymphoma (HL) cell line and biodistribution in HL bearing mice of new anti-CD30 radioimmunoconjugates (RICs) of varying structure and labelling nuclides. Methods: The antibodies Ki-4 and 5F11 were radioiodinated by the chloramine T method or labelled with 111In via p-NCS-Benzyl-DOTA. In addition, the Ki-4-dimer was investigated in the iodinated form. The RICs were analyzed for retained immunoreactivity by immunochromatography. In-vitro binding studies were performed on CD30-positive L540 cell lines. For in-vivo biodistribution studies, SCID mice bearing human HL xenografts were injected with the various radio-immunoconjugates. After 24 h, activities in the organs and tumour were measured for all 5 RICs. Tumour-free animals were studied in the same way with 131I-Ki-4 24 h p. i. The three RICs with the highest tumour/background ratios 24 h p.i. (131I-Ki-4, 131I-5F11, 111In-bz-DOTA-Ki-4) were analysed further at 48 h and 72 h. Results: all the RICs were successfully labelled with high specific activities (28-47 TBq/mmol) and sufficient radiochemical yields (> 80%). Scatchard plot analysis proved high tumour affinity (KD = 20-220 nmol/l). In-vivo tumour accumulation in % of injected dose per g tissue (% ID/g) lay between 2.6 (131I-5F11) and 12.3 % ID/g (131I-Ki-4) with permanently high background in blood. Tumour/blood-ratios of all RICs were below one at all time points. Conclusions: in-vitro tumour cell affinities of all RICs were promising. However, in-vivo biokinetics tested in the mouse model did not meet expectations. This highlights the importance of developing and testing further new anti-CD30 conjugates. (orig.)

  3. A radioimmunoassay detecting the borine leukaemia virus transmembrane protein gp30 and anti-gp30 antibodies in the serum of cattle

    International Nuclear Information System (INIS)

    From virus-infected fetal lamb kidney (FLK) cells a relatively homogeneous envelope transmembrane protein gp30 of bovine leukemia virus (BLV) was isolated. As shown by a partial sequence analysis of the N-terminus of this protein, the gp30 preparation contained only traces (less than 5%) of p24 gag protein: rabbit anti-gp30 serum did not cross react with the BLV proteins gp51, p12, p151, p152 and p10 but reacted weakly with the p24 polypeptide. 125I-labelled gp30 (chloramine-T) was precipitated with the serum of BLV-infected cattle. Nonlabelled preparation of gp30 competitively inhibited the reaction of 125I-labelled gp30 with natural antibodies. 193 cattle sera were investigated by liquid phase radioimmunoassay (RIA) using 125I-gp30, gp51 and p24 antigens. Sixteen noninfected cattle sera were negative in all tests. The 177 serum samples of BLV-infected animals were examined to the diagnostic value of the three tests. Of these, 175 were positive in gp51 RIA, 172 in p24 RIA and 164 in gp30 RIA. In all three tests, 159 sera were positive while 18 sera, mostly coming from animals with normal leukocyte counts, were positive only either with gp51 or p24, or were double positive with either gp51/p24 or gp51/gp30. It is concluded that gp51 RIA is superior to both gp30 and p24 RIA and that gp30 RIA will be useful for investigating the role of gp30 in virus pathogenicity. (author). 2 figs., 2 tabs., 33 refs

  4. Fast determination of cyanide by paper disk method%氰化物纸片快速测定食品中的氰化物

    Institute of Scientific and Technical Information of China (English)

    杨俊; 陈亿展; 孟令兵; 赖小丽; 李意

    2012-01-01

    目的:建立食品中氰化物的纸片速测法并应用于重大活动保障中.方法:食品中的氰化物经水浸取后,与氯胺T反应生成氯化氰,继而与异烟酸反应,并经水解而成戊烯二醛,最后与1,3-二甲基巴比妥酸作用生成紫蓝色化合物,比色定量.结果:方法检出限为1.00 mg/kg,准确度和精密度都较为理想.结论:氰化物纸片速测法具有灵敏度高,快速,携带方便的特点,适合于重大活动保障中氰化物的快速测定.%Objective:To establish a method for fast determination of cyanide in food by paper disk method in important Activities. Methods: Cyanide in food was leached with water,and then reacted with chloramine T to form ey-anochloride which reacted with isonicotinic acid, the product was hydrolyed to glutaconaldehyde, and finally it reacted with 1,3- dimethyl barbituric acid to form a violet blue compound. The content of cyanide was quantitated colorime-trically. Results: The detection limit of the method was 1. 00 mg/kg, the recoveries and the precision were satisfactory. Conclusion: The method was sensitive, fast and convenient. It is suitable to determine cyanide in food in important Activities.

  5. Role of the metabolism of parathyroid hormone. [Rats

    Energy Technology Data Exchange (ETDEWEB)

    Teitelbaum, Anne P.

    1978-01-01

    The heterogeneity of parathyroid hormone (PTH) in plasma has prompted investigations of the metabolism of PTH and its relationship to hormone action. The time course of tissue distribution and metabolism of electrolytically iodinated PTH (E-PTH) previously shown to retain biological activity was compared with that of inactive PTH iodinated with Chloramine-T (CT-PTH). Labeled PTH (0.4 ..mu..g) was injected in the saphenous veins of anesthetized rats which were sacrificed at 1, 3, 5, 10, and 20 min. Tissue extracts from kidney, liver, and serum were chromatographed to separate intact PTH from its metabolites. In the kidney, the initial rate of degradation of E-PTH was greater than that of CT-PTH. The difference in initial rates of metabolism may be due, in part, to receptor-specific hydrolysis on peritubular cell membranes which selectively act on biologically active PTH molecules. PTH-responsive adenyl cyclase activity in isolated kidney cortex plasma membranes was measured and PTH metabolism was monitored simultaneously. When degradation was completely blocked by histone f/sub 3/ (1 mg/ml), adenyl cyclase activity was significantly increased over control. In addition, when adenyl cyclase activity was negligible, the rate of PTH degradation by the membranes was not significantly diminished. Consistent with the in vivo data was the observation that E-PTH is metabolized by these membranes at a greater rate than CT-PTH. The data demonstrate the existence of a receptor-specific metabolism at sites which are independent of PTH receptor mediated adenyl cyclase activity.

  6. Preparation of mono-radioiodinated tracers for study of the in vivo metabolism of atrial natriuretic peptide in humans

    Energy Technology Data Exchange (ETDEWEB)

    Clerico, A. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Iervasi, G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Manfredi, C. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Salvadori, S. [Dept. of Pharmaceutical Sciences, Univ. of Ferrara (Italy); Marastoni, M. [Dept. of Pharmaceutical Sciences, Univ. of Ferrara (Italy); Del Chicca, M.G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Giannessi, D. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Del Ry, S. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Andreassi, M.G. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Sabatino, L. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Iascone, M.R. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Biagini, A. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica; Donato, L. [Consiglio Nazionale delle Ricerche, Pisa (Italy). Lab. di Fisiologia Clinica

    1995-09-01

    The authors evaluate the optimum chemical conditions for labelling atrial natriuretic peptide (ANP) and its metabolites and for preparing highly purified radiotracers which can be used for in vivo kinetic studies of ANP in humans. Synthetic {alpha} h{sub 1-28}ANP and some hormone metabolites were iodinated with Na{sup 125}I or Na{sup 131}I by means of the lactoperoxidase (ANP) or the chloramine-T (ANP metabolites) technique. The biological activity of labelled ANP was tested by means of a binding study using mouse cardiac membranes. A high-performance liquid chromatography (HPLC) procedure was used to purify the labelled hormone and the principal labelled metabolites in venous plasma samples collected up to 50 min after the injection of {sup 125}I-labelled ANP from nine healthy men. The main ANP kinetic parameters were derived from the disappearance curves of the [{sup 125}I]ANP, which were satisfactorily fitted by a bi-exponential function in all subjects. The main advantages of this tracer technique are high accuracy, allowing the identification of the metabolites produced in vivo under steady-state conditions after injection of the precursor (labelled hormone) high sensitivity, allowing the detection of minimal quantities of metabolites high specificity, allowing the detection of possible in vitro artefactual generation of cleavage products of ANP using an internal labelled standard. Utilizing this tracer method, it was possible to estimate the principal parameters of ANP kinetics and also to plot the appearance curves of the labelled metabolites produced in vivo after the injection of the labelled precursor. (orig.). With 5 figs.

  7. DRINKING WATER DISINFECTION BYPRODUCTS:CHEMICAL CHARACTERIZATION AND TOXICITY%饮用水消毒副产物:化学特征与毒性

    Institute of Scientific and Technical Information of China (English)

    赵玉丽; 李杏放

    2011-01-01

    Disinfection of drinking water is essential to and effective for the prevention of water-borne diseases.While achieving deactivation of microbial pathogens to minimize the acute risk, an unintentional consequence is the formation of disinfection byproducts (DBPs) resulting from reactions of disinfectants with natural organic materials (NOMs) in water. Epidemiological studies show potential associations of increased risk of bladder cancer and adverse health effects with DBPs. Balancing microbial risk with chemical risk is challenging for public health protection. Currently, the most commonly used disinfectants are chlorine, chlorine dioxide,chloramines and ozone. Here we provide an overview of chemical characterization, toxicity and analytical methods of 10 classes of DBPs, including trihalomethanes ( THMs), haloacefic acids ( HAAs), bromate ( BrO3- ), chlorite ( ClO2- ), haloacetonitriles (HANs), mutagen X (MX), halonitromethane ( HNMs), iodo acids (IAs), N-nitrosodimethylamines (NMs) and halobenzoquinones (HBQs). We will discuss the challenges and opportunities in the research of DBPs and health effects.%饮用水消毒过程中消毒剂与天然有机物(NOMs)反应生成消毒副产物(DBPs).本文针对氯、氯胺、二氧化氯、臭氧4种主要消毒方式产生的消毒副产物,综述了10类DBPs的化学特性、毒性和分析方法.具体包括:三卤甲烷(THMs)、卤乙酸(HAAs)、溴酸盐(BrO3-)、亚氯酸盐(CIO2-)、卤乙腈(HANs)、致诱变化合物(MX)、卤代硝基甲烷(HNMs)、碘代酸(Ias)、亚硝胺(NMs)以及卤代对苯醌(HBQs).

  8. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell

    Science.gov (United States)

    Huang, Xiao; Qu, Yan; Cid, Clément A.; Finke, Cody; Hoffmann, Michael R.; Lim, Keahying; Jiang, Sunny C.

    2016-01-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [•OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source. PMID:26854604

  9. Free Radical Chemistry of Disinfection Byproducts 1: Kinetics of Hydrated Electron and Hydroxyl Radical Reactions with Halonitromethanes in Water

    Energy Technology Data Exchange (ETDEWEB)

    B. J. Mincher; R. V. Fox; S. P. Mezyk; T. Helgeson; S. K. Cole; W. J. Cooper; P. R. Gardinali

    2006-01-01

    Halonitromethanes are disinfection-byproducts formed during ozonation and chlorine/chloramine treatment of waters that contain bromide ion and natural organic matter. In this study, the chemical kinetics of the free-radical-induced degradations of a series of halonitromethanes were determined. Absolute rate constants for hydroxyl radical, OH, and hydrated electron, eaq-, reaction with both chlorinated and brominated halonitromethanes were measured using the techniques of electron pulse radiolysis and transient absorption spectroscopy. The bimolecular rate constants obtained, k (M-1 s-1), for eaq-/OH, respectively, were the following: chloronitromethane (3.01 ± 0.40) × 1010/(1.94 ± 0.32) × 108; dichloronitromethane (3.21 ± 0.17) × 1010/(5.12 ± 0.77) × 108; bromonitromethane (3.13 ± 0.06) × 1010/(8.36 ± 0.57) × 107; dibromonitromethane (3.07 ± 0.40) × 1010/(4.75 ± 0.98) × 108; tribromonitromethane (2.29 ± 0.39) × 1010/(3.25 ± 0.67) × 108; bromochloronitromethane (2.93 ± 0.47) × 1010/(4.2 ± 1.1) × 108; bromodichloronitromethane (2.68 ± 0.13) × 1010/(1.02 ± 0.15) × 108; and dibromochloronitromethane (2.95 ± 0.43) × 1010 / (1.80 ± 0.31) × 108 at room temperature and pH ~7. Comparison data were also obtained for hydroxyl radical reaction with bromoform (1.50 ± 0.05) × 108, bromodichloromethane (7.11 ± 0.26) × 107, and chlorodibromomethane (8.31 ± 0.25) × 107 M-1 s-1, respectively. These rate constants are compared to recently obtained data for trichloronitromethane and bromonitromethane, as well as to other established literature data for analogous compounds.

  10. Acetonitrile and N-Chloroacetamide Formation from the Reaction of Acetaldehyde and Monochloramine.

    Science.gov (United States)

    Kimura, Susana Y; Vu, Trang Nha; Komaki, Yukako; Plewa, Michael J; Mariñas, Benito J

    2015-08-18

    Nitriles and amides are two classes of nitrogenous disinfection byproducts (DBPs) associated with chloramination that are more cytotoxic and genotoxic than regulated DBPs. Monochloramine reacts with acetaldehyde, a common ozone and free chlorine disinfection byproduct, to form 1-(chloroamino)ethanol. Equilibrium (K1) and forward and reverse rate (k1,k-1) constants for the reaction between initial reactants and 1-(chloroamino)ethanol were determined between 2 and 30 °C. Activation energies for k1 and k-1 were 3.04 and 45.2 kJ·mol(-1), respectively, and enthalpy change for K1 was -42.1 kJ·mol(-1). In parallel reactions, 1-(chloroamino)ethanol (1) slowly dehydrated (k2) to (chloroimino)ethane that further decomposed to acetonitrile and (2) was oxidized (k3) by monochloramine to produce N-chloroacetamide. Both reactions were acid/base catalyzed, and rate constants were characterized at 10, 18, and 25 °C. Modeling for drinking water distribution system conditions showed that N-chloroacetamide and acetonitrile concentrations were 5-9 times higher at pH 9.0 compared to 7.8. Furthermore, acetonitrile concentration was found to form 7-10 times higher than N-chloroacetamide under typical monochloramine and acetaldehyde concentrations. N-chloroacetamide cytotoxicity (LC50 = 1.78 × 10(-3) M) was comparable to dichloroacetamide and trichloroacetamide, but less potent than N,2-dichloroacetamide and chloroacetamide. While N-chloroacetamide was not found to be genotoxic, N,2-dichloroacetamide genotoxic potency (5.19 × 10(-3) M) was on the same order of magnitude as chloroacetamide and trichloroacetamide.

  11. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell.

    Science.gov (United States)

    Huang, Xiao; Qu, Yan; Cid, Clément A; Finke, Cody; Hoffmann, Michael R; Lim, Keahying; Jiang, Sunny C

    2016-04-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source.

  12. Occurrence of selected aliphatic amines in source water of major cities in China

    Institute of Scientific and Technical Information of China (English)

    Haifeng Zhang; Shuoyi Ren; Jianwei Yu; Min Yang

    2012-01-01

    The formation of toxic nitrogenous disinfection byproducts (N-DBPs),such as nitrosamines,halonitromethanes and haloacetonitriles,from reactions between chlorine/chloramine and dissolved organic nitrogen in drinking water has caused great concern with regarding public health.This study revealed the occurrence of 17 aliphatic amines,some of which have been confirmed to be the precursors of N-DBPs,in source water across China.A sensitive method based on benzenesulfonyl chloride derivatization and liquid-liquid extraction followed by GC-MS analysis was established for the simultaneous analysis of the selected amines in aqueous samples.In total,37 source water samples from the capital cities of 20 provinces were collected for the survey.Among the 17 amines,14 were detected with an average frequency of detection of 36%.The most relevant amines in terms of frequency and maximum concentrations detected were dimethylamine (100%,24.82 μg/L),methylamine (78%,0.92 μg/L),N-methylethylamine (70%,8.84 μg/L),propylamine (59%,10.69 μg/L),diethylamine (54%,3.76 μg/L),N-methylbutylamine (35%,3.07 μg/L),N-ethylpropylamine (35%,0.52 μg/L),and piperidine (32%,2.35 μg/L).This is the first large scale survey of the aliphatic amines occurrence in source water in the world.The wide presence of nitrosamine precursors like dimethylamine,N-methylethylamine and diethylamine,and the precursors of haloacetonitriles and halonitromethanes like methylamine and propylamine suggests that better source water management is required to ensure the safety of drinking water.

  13. Identifying unknown by-products in drinking water using comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry and in silico toxicity assessment.

    Science.gov (United States)

    Li, Chunmei; Wang, Donghong; Li, Na; Luo, Qian; Xu, Xiong; Wang, Zijian

    2016-11-01

    Improvements in extraction and detection technologies have increased our abilities to identify new disinfection by-products (DBPs) over the last 40 years. However, most previous studies combined DBP identification and measurement efforts with toxicology to address concerns on a few expected DBPs, making it difficult to better define the health risk from the individual DBPs. In this study, a nontargeted screening method involving comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS) combined with OECD QSAR Toolbox Ver. 3.2 was developed for identifying and prioritizing of volatile and semi-volatile DBPs in drinking water. The method was successfully applied to analyze DBPs formed during chlorination, chloramination or ozonation of the raw water. Over 500 compounds were tentatively identified in each sample, showing the superior performance of this analytical technique. A total of 170 volatile and semi-volatile DBPs representing fourteen chemical classes were then identified, according to the criteria that the DBP was presented in the duplicate treated samples. The genotoxicity and carcinogenicity of the DBPs were evaluated using Toolbox, and 58 DBPs were found to be actual or potential genotoxicants. The accuracy of the compound identification was determined by comparing 47 identified compounds with commercially available standards. About 90% (41 of the 47) of the compounds that were automatically identified using the library were correct. The results show that GC×GC-qMS coupled with a quantitative structure-activity relationship model is a powerful and fast nontargeted screening technique for compounds. The method and results provide us a new idea for identification and prioritization of DBPs.

  14. Theoretical Studies on F(-) + NH2Cl Reaction: Nucleophilic Substitution at Neutral Nitrogen.

    Science.gov (United States)

    Liu, Xu; Zhang, Jiaxu; Yang, Li; Sun, Rui

    2016-05-26

    The SN2 reactions at N center, denoted as SN2@N, has been recognized to play a significant role in carcinogenesis, although they are less studied and less understood. The potential energy profile for the model reaction of SN2@N, chloramine (NH2Cl) with fluorine anion (F(-)), has been characterized by extensive electronic structure calculations. The back-side SN2 channel dominates the reaction with the front-side SN2 channel becoming feasible at higher energies. The minimum energy pathway shows a resemblance to the well-known double-well potential model for SN2 reactions at carbon. However, the complexes involving nitrogen on both sides of the reaction barrier are characterized by NH---X (X = F or Cl) hydrogen bond and possess C1 symmetry, in contrast to the more symmetric ion-dipole carbon analogues. In the F(-) + NH2Cl system, the proton transfer pathway is found to become more competitive with the SN2 pathway than in the F(-) + CH3Cl system. The calculations reported here indicate that stationary point properties on the F(-) + NH2Cl potential energy surface are slightly perturbed by the theories employed. The MP2 and CAM-B3LYP, as well as M06-2X and MPW1K functionals give overall best agreement with the benchmark CCSD(T)/CBS energies for the major SN2 reaction channel, and are recommended as the preferred methods for the direct dynamics simulations to uncover the dynamic behaviors of the title reaction. PMID:27144809

  15. Transformation of acetaminophen during water chlorination treatment: kinetics and transformation products identification.

    Science.gov (United States)

    Cao, Fei; Zhang, Mengtao; Yuan, Shoujun; Feng, Jingwei; Wang, Qiquan; Wang, Wei; Hu, Zhenhu

    2016-06-01

    As a high-consumption drug in the world, acetaminophen (AAP) has been widely detected in natural waters and wastewaters. Its reactivity and the transformation products formed during chlorination may greatly threaten the safety of drinking water. The reaction kinetics of AAP during chlorination was investigated in this study. The results showed that the reaction kinetics could be well described with a kinetics model of -d[AAP]/dt = k app[AAP]t (0.63)[Cl2]t (1.37). The values of apparent rate constant (k app) were dependent on reaction temperature, ammonium, and pH. With the increase in reaction temperature from 5.0 ± 1.0 to 40.0 ± 1.0 °C, the removal efficiency of AAP increased from 60 to 100 %. When ammonium was present in the solution at 2.0 mg/L, the transformation of AAP was inhibited due to the rapid formation of chloramines. The maximum of k app was 0.58 × 10(2) M(-1) · min(-1) at pH 9.0, and the minimum was 0.27 M(-1) · min(-1) at pH 11.0. A low mineralization of AAP (about 7.2 %) with chlorination was observed through TOC analysis, implying the formation of plenty of transformation products during chlorination. The main transformation products, hydroquinone and two kinds of chlorinated compounds, monochlorinated acetaminophen and dichlorinated acetaminophen, were detected in gas chromatography-mass spectrometry analysis. PMID:26983813

  16. Blood-brain barrier transport of cationized immunoglobulin G: Enhanced delivery compared to native protein

    Energy Technology Data Exchange (ETDEWEB)

    Triguero, D.; Buciak, J.B.; Yang, J.; Pardridge, W.M.

    1989-06-01

    IgG molecules are potential neuropharmaceuticals that may be used for therapeutic or diagnostic purposes. However, IgG molecules are excluded from entering brain, owing to a lack of transport of these plasma proteins through the brain capillary wall, or blood-brain barrier (BBB). The possibility of enhanced IgG delivery through the BBB by cationization of the proteins was explored in the present studies. Native bovine IgG molecules were cationized by covalent coupling of hexamethylenediamine and the isoelectric point was raised to greater than 10.7 based on isoelectric focusing studies. Native and cationized IgG molecules were radiolabeled with /sup 125/I and chloramine T. Cationized IgG, but not native IgG, was rapidly taken up by isolated bovine brain microvessels, which were used as an in vitro model system of the BBB. Cationized IgG binding was time and temperature dependent and was saturated by increasing concentrations of unlabeled cationized IgG (dissociation constant of the high-affinity binding site, 0.90 +/- 0.37 microM; Bmax, 1.4 +/- 0.4 nmol per mg of protein). In vivo studies documented enhanced brain uptake of 125I-labeled cationized IgG relative to (3H)albumin, and complete transcytosis of the 125I-labeled cationized IgG molecule through the BBB and into brain parenchyma was demonstrated by thaw-mount autoradiography of frozen sections of rat brain obtained after carotid arterial infusions of 125I-labeled cationized IgG. These studies demonstrate that cationization of IgG molecules greatly facilitates the transport of these plasma proteins through the BBB in vivo, and this process may provide a new strategy for IgG delivery through the BBB.

  17. Preparation of mono-radioiodinated tracers for study of the in vivo metabolism of atrial natriuretic peptide in humans

    International Nuclear Information System (INIS)

    The authors evaluate the optimum chemical conditions for labelling atrial natriuretic peptide (ANP) and its metabolites and for preparing highly purified radiotracers which can be used for in vivo kinetic studies of ANP in humans. Synthetic α h1-28ANP and some hormone metabolites were iodinated with Na125I or Na131I by means of the lactoperoxidase (ANP) or the chloramine-T (ANP metabolites) technique. The biological activity of labelled ANP was tested by means of a binding study using mouse cardiac membranes. A high-performance liquid chromatography (HPLC) procedure was used to purify the labelled hormone and the principal labelled metabolites in venous plasma samples collected up to 50 min after the injection of 125I-labelled ANP from nine healthy men. The main ANP kinetic parameters were derived from the disappearance curves of the [125I]ANP, which were satisfactorily fitted by a bi-exponential function in all subjects. The main advantages of this tracer technique are high accuracy, allowing the identification of the metabolites produced in vivo under steady-state conditions after injection of the precursor (labelled hormone) high sensitivity, allowing the detection of minimal quantities of metabolites high specificity, allowing the detection of possible in vitro artefactual generation of cleavage products of ANP using an internal labelled standard. Utilizing this tracer method, it was possible to estimate the principal parameters of ANP kinetics and also to plot the appearance curves of the labelled metabolites produced in vivo after the injection of the labelled precursor. (orig.). With 5 figs

  18. The structure of flavin-dependent tryptophan 7-halogenase RebH

    Energy Technology Data Exchange (ETDEWEB)

    Bitto, Eduard; Huang, Yu; Bingman, Craig A.; Singh, Shanteri; Thorson, Jon S.; Phillips, Jr., George N. (UW)

    2010-02-19

    Enzyme catalyzed regio- and stereo-specific halogenations influence the biological activity of a diverse array of therapeutically important natural products, including the antibiotics vancomycin and chloramphenicol as well as the anticancer agents calicheamicin and rebeccamycin. The major class of enzymes responsible for this challenging synthetic reaction, the flavin-dependent halogenases, catalyzes the formation of carbon-halogen bonds using flavin, a halide ion (Cl{sup -}, Br{sup -} or I{sup -}), and O{sub 2}. Recent mechanistic and structural advances achieved with the model flavin-dependent tryptophan 7-halogenases PrnA and RebH have greatly enhanced the level of understanding of this unique reaction. According to these studies, the mechanism for tryptophan halogenation proceeds via FAD(C4a)-OOH activation of a chloride ion into the transient chlorinating species HOCl. The key evidence for the requirement of a transient chlorinating species is the discovery that a {approx}10-{angstrom}-long tunnel separates FAD and tryptophan in the ligand-bound form of PrnA. In a recent compelling study to elucidate the strategy by which RebH controls this highly reactive and indiscriminant oxidant, a Lys79-{var_epsilon}NH-Cl chloramine intermediate was implicated as the actual chlorinating species within RebH and a structural investigation of RebH was reported. Here we report our independent structural analysis of Lechevalieria aerocolonigenes RebH (Uni-Prot accession number Q8KHZ8, 530 amino acids) in its apo-form as well as in a complex with both tryptophan and FAD.

  19. Evaluating Evidence for Association of Human Bladder Cancer with Drinking-Water Chlorination Disinfection By-Products.

    Science.gov (United States)

    Hrudey, Steve E; Backer, Lorraine C; Humpage, Andrew R; Krasner, Stuart W; Michaud, Dominique S; Moore, Lee E; Singer, Philip C; Stanford, Benjamin D

    2015-01-01

    Exposure to chlorination disinfection by-products (CxDBPs) is prevalent in populations using chlorination-based methods to disinfect public water supplies. Multifaceted research has been directed for decades to identify, characterize, and understand the toxicology of these compounds, control and minimize their formation, and conduct epidemiologic studies related to exposure. Urinary bladder cancer has been the health risk most consistently associated with CxDBPs in epidemiologic studies. An international workshop was held to (1) discuss the qualitative strengths and limitations that inform the association between bladder cancer and CxDBPs in the context of possible causation, (2) identify knowledge gaps for this topic in relation to chlorine/chloramine-based disinfection practice(s) in the United States, and (3) assess the evidence for informing risk management. Epidemiological evidence linking exposures to CxDBPs in drinking water to human bladder cancer risk provides insight into causality. However, because of imprecise, inaccurate, or incomplete estimation of CxDBPs levels in epidemiologic studies, translation from hazard identification directly to risk management and regulatory policy for CxDBPs can be challenging. Quantitative risk estimates derived from toxicological risk assessment for CxDBPs currently cannot be reconciled with those from epidemiologic studies, notwithstanding the complexities involved, making regulatory interpretation difficult. Evidence presented here has both strengths and limitations that require additional studies to resolve and improve the understanding of exposure response relationships. Replication of epidemiologic findings in independent populations with further elaboration of exposure assessment is needed to strengthen the knowledge base needed to better inform effective regulatory approaches.

  20. {sup 123}I-BPA and {sup 123}I-BPA-fructose complex as a new radiopharmaceutical for the imaging of amino acid transport in tumor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, T. H.; Choi, C. W.; Woo, K. S.; Chung, W. S.; Lim, S. J.; Lee, S. J.; Hong, S. W.; Lim, S. M. [Korea Cancer Center, Seoul (Korea, Republic of)

    1999-07-01

    Boronophenylalanine (BPA) as derivative of phenylalanine, was used to treatment for glioma and melanoma in BNCT. We labeled BPA with radioiodides for tumor imaging of amino acid transport with gamma camera. Because of limited solubility of BAP, I-BPA-Fructose(I-BPA was complexed with fructose) to increase solubility. I-BPA was labeled by chloramine T coated bead method. Serum stability of I-BPA analyzed by HPLC at 37 .deg. C. Cellular uptake of I-BPA and I-BPA-Fructose was compared in 9L glioma and B16 melanoma. To see biodistribution, I-BPA 9x10{sup 5}Bq(20 {mu}g/100 {mu}l) or I-BPA-Fructose 9x10{sup 5}Bq(20 {mu}g/fructose 55 {mu}g/100 {mu}l) was injected to B16 melanoma bearing C57 mice. In tumor bearing mice at 30 min, 1, 2, 24 hr after injection of tracers (n-4 per group). In 24hr, radiochemical purity of I-BPA in serum was retained above 90%. In cultured cells the maximum uptake was observed at 60min. In 9L glioma cells, %uptake of I-BPA and I-BPA-Fructose was 2.05, 2.6 at 60min. But in B16 melanoma, %uptake of I-BPA and I-BPA and-Fructose was 2.57, 6.62 at 60 min. In melanoma bearing mice, tumor/muscle ratio of I-BPA in 30 min, 1hr, 2hr, 24hr after injection was 1.48, 2.19, 2.28, 0.29 and %ID/g of tumor was 6.25, 5.17, 3.52, 0.29. Tumor/muscle ratio of I-BPA-Fructose was 1.51, 2.05, 2.1, 2.84 in 30 min, 1hr, 2hr, 24hr post-injection and %ID/g of tumor was 4.61, 3.65, 2.93, 0.71. The radioactivity was excreted mainly via hepatobiliary tract to the intestine. I-BPA was stable in serum upto 24hr. Uptake of I-BPA-Fructose was higher than I-BPA in melanoma cells. I-BPA-Fructose, is a promising tumor imaging radiopharmaceutical in some tumors.

  1. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of {sup 60}Co; Estudo bioquimico e farmacologico das crotaminas nativa e irradiada com radiacao gama de {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Mitake, Malvina Boni

    2000-07-01

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from the South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of this thesis was carry out biochemical and pharmacological studies of native and irradiated crotamine with {sup 60} Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast Performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 M Na Cl with 2.0 kGy gamma radiation emitted by a {sup 60} Co source. The native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD{sub 50} and biodistribution. The native and irradiated crotamine were labelled with 29.6 MBq of {sup 125} I using chloramine T method, and separated in a Sephadex G-50 column. Male Swiss mice (35{+-} 5 g), were injected i.p. with o.1 mL (2.4 x 10{sup 6} cpm/mouse) of {sup 125} I native crotamine or with 0.4 mL (1.3 x 10{sup 6} cpm/mouse) of {sup 125} I irradiated crotamine. At 0.08; 0.25; 0.5; 1; 2; 4; 8; 12 and 24 hours the animal were killed by ether inhalation. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change the protein concentration, the electroforetic profile or the primary structure of the protein, although differences were shown by spectroscopic techniques. The gamma radiation diminished the toxicity of crotamine, but it did not abolish bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. The native and irradiated crotamine have affinity by skeletal

  2. Development of anti-CD30 radioimmunoconstructs (RICs) for treatment of Hodgkin's lymphoma. Studies with cell lines and animal studies

    Energy Technology Data Exchange (ETDEWEB)

    Dietlein, M.; Boerner, S.M.; Fischer, T.; Zimmermanns, B.; Kobe, C.; Schicha, H.; Schomaecker, K. [Dept. of Nuclear Medicine, Univ. of Cologne (Germany); Hansen, H.; Schnell, R.; Tawadros, S.; Engert, A.; Staak, O.; Pogge von Strandmann, E. [Dept. of Internal Medicine I, Univ. of Cologne (Germany)

    2010-07-01

    Objectives: comparison of the binding affinity to a CD30-positive Hodgkin lymphoma (HL) cell line and biodistribution in HL bearing mice of new anti-CD30 radioimmunoconjugates (RICs) of varying structure and labelling nuclides. Methods: The antibodies Ki-4 and 5F11 were radioiodinated by the chloramine T method or labelled with {sup 111}In via p-NCS-Benzyl-DOTA. In addition, the Ki-4-dimer was investigated in the iodinated form. The RICs were analyzed for retained immunoreactivity by immunochromatography. In-vitro binding studies were performed on CD30-positive L540 cell lines. For in-vivo biodistribution studies, SCID mice bearing human HL xenografts were injected with the various radio-immunoconjugates. After 24 h, activities in the organs and tumour were measured for all 5 RICs. Tumour-free animals were studied in the same way with {sup 131}I-Ki-4 24 h p. i. The three RICs with the highest tumour/background ratios 24 h p.i. ({sup 131}I-Ki-4, {sup 131}I-5F11, {sup 111}In-bz-DOTA-Ki-4) were analysed further at 48 h and 72 h. Results: all the RICs were successfully labelled with high specific activities (28-47 TBq/mmol) and sufficient radiochemical yields (> 80%). Scatchard plot analysis proved high tumour affinity (K{sub D} = 20-220 nmol/l). In-vivo tumour accumulation in % of injected dose per g tissue (% ID/g) lay between 2.6 ({sup 131}I-5F11) and 12.3 % ID/g ({sup 131}I-Ki-4) with permanently high background in blood. Tumour/blood-ratios of all RICs were below one at all time points. Conclusions: in-vitro tumour cell affinities of all RICs were promising. However, in-vivo biokinetics tested in the mouse model did not meet expectations. This highlights the importance of developing and testing further new anti-CD30 conjugates. (orig.)

  3. Development of a new radioimmunoassay for erythropoietin using recombinant erythropoietin

    Energy Technology Data Exchange (ETDEWEB)

    Mason-Garcia, M.; Beckman, B.S.; Brookins, J.W.; Powell, J.S.; Lanham, W.; Blaisdell, S.; Keay, L.; Li, S.C.; Fisher, J.W. (Tulane Univ. School of Medicine, New Orleans, LA (USA))

    1990-11-01

    The development of a 24 hour radioimmunoassay for erythropoietin (EPO) using EPO derived from recombinant DNA as both immunogen and ligand is described in the present paper. Mixed breed rabbits immunized with 10 micrograms/kg of EPO derived from a stably transfected cell line (MD) produced antibodies to EPO with high titer (up to 1:896,000 final dilution in the tube), high affinity (8.4 x 10(11) liter/M), and good specificity. Purified EPO from the above source or from AmGen Biologicals (AG) were successfully radioiodinated with the chloramine-T method and used as ligand in the radioimmunoassay. Standard dose-response curves prepared with EPO from both commercial sources were not significantly different and showed a sensitivity of 0.75 to 0.96 mU/tube. The dose-response curves in both systems also showed parallelism with serially diluted serum from a patient with aplastic anemia. Within-assay and between-assay precision were determined by assaying multiple replicates of a serum pool. Recovery of exogenous EPO added to a serum pool averaged 97% for both systems. The range of normal human serum EPO was determined by assaying the sera of 153 hematologically-normal adult subjects and was found to be 1.1 to 27.3 mU/ml for MD EPO and 0.5 to 16.7 mU/ml for AG EPO. Sera from several patients with hematologic abnormalities were also assayed, including those of 36 patients with anemia of end-stage renal disease (mean +/- SEM, 29.5 +/- 4.0 mU/ml; P less than 0.01). In conclusion, this new, more rapid and sensitive radioimmunoassay system can be used to measure EPO levels in sera from normal human subjects and patients with several types of anemia, and should also be very useful in therapeutic drug monitoring of patients receiving EPO from various commercial sources.

  4. Immunoassay of taxol using anti-taxol antibody and radiolabeled taxol

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T. S.; Hong, J. P.; Kim, H. S.; Awh, O. D.; Choi, C. W.; Lim, S. M. [College of Medicine, Yonsei Univ., Wonju (Korea, Republic of)

    2000-07-01

    Taxol (Paclitaxel), an antineoplastic agent, has been used for treatment of ovarian and breast cancer. Prompt analysis of taxol concentration in the human serum is beneficial to maintain an appropriate taxol concentration in blood, which will enhance therapeutic effect of the drug. This study was aimed to establish a radioimmunoassay system for monitoring the taxol level in blood during cancer treatment. Hemisuccinyltaxol (HT) was synthesized by esterification of taxol with succinic anhydride. Tyraminehemisuccinyltaxol (THT) was synthesized by amide bond formation of the hemisuccinyltaxol with tyramine in the presence of isobutylchloroformate. The synthesized THT was purified by HPLC, Tyraminehemisuccinyltaxol was dissolved in 80% acetonitrile solution, which was stored at 4 .deg. C or 37 .deg. C for 7 days. The stability of tyraminehemisuccinyltaxol was monitored during the storage period. Tyramine-hemisuccinyltaxol was labeled with {sup 125}I (3.7 x 10{sup 7} Bq) by Chloramine-T. The radiolabeled product, ({sup 125}I)iodo-tyraminehemiscuccinyltasol, was allowed to stand at 4 .deg. C or 37 .deg. C for up to 7 days to estimate its stability. The radiochemical purity of ({sup 125}I) iodotyramine-hemisuccinyltaxol was determined by HPLC. In other hand, the titer of taxol monoclonal antibody (3G5A7) was determined by radioimmunoassay using ({sup 125}I) iodotyramine-hemisuccinyltaxol as a radiolabeled antigen. A standard dose response curve was plotted by taxolcompetitive radioimmunoassay. Hemisuccinyltaxol was synthesized with 79.9% yield. Tyraminehemisuccinyltaxol was synthesized with 19.5% yield and purified by HPLC. the chemical purity of Tyraminehemisuccinyltaxol was maintained at 96.5% and 97.5% after 7 days storage at 4 .deg. C and 37.deg. C respectively. The radiochemical purity of ({sup 125}I) iodotyramine-hemisuccinyltaxol was diminished to 88.1% and 86.2% after 7 days storage at 4 .deg. C and 37. deg.C, respectively. The antibody titer against taxol was 1

  5. Preparation of {sup 125}I-iodotyraminehemisuccinyltaxol ({sup 125}ITHT) for competitive taxol radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae Sup; Awh, Ok Doo; Choi, Tae Hyun; Kim, Hyun Suk; Hong, Jun Pyo; Lee, Eun Sook [College of Medicine, Yonsei Univ., Wonju (Korea, Republic of); Choi, Chang Woon; Lim, Sang Moo [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    2002-04-01

    Taxol(Paclitaxel), an antineoplastic agent, has been used in the treatment of ovarian and breast cancers. The determination of optimal Taxol concentrations in human serum was required for enhancing therapeutic effect and maintaining the appropriate Taxol level in blood. This study was aimed to synthesize radiolabeled Taxol derivatives as radiotracer in competitive radioimmuoassay for monitoring Taxol concentrations in blood and to determine the usefulness of its derivatives. Hemisuccinyltaxol(HT) was synthesized by esterification of Taxol with succinic anhydride. Tyraminehemisuccinyltaxol (THT) was synthesized by coupling of HT with tyramine using isobutylchloroformate as coupling agent and purified by HPLC. By using chloramine-T(5.25 mg/ml, 10 {mu}l) as oxidant agent, THT (4 mg/ml, 30 {mu}l) was labeled with {sup 125}I (37 MBq, 1 mCi). To estimate the stability of purified THT, {sup 125}I-iodotyraminehemisuccinyltaxol ({sup 125}ITHT) was dissolved in 80% acetonitrile aqueous solution, and the solution was incubated at 4 .deg. C and 37 .deg. C for 7 days. At various time intervals, the stability of THT and {sup 125}ITHT was monitored. The titer of Taxol monoclonal antibody, 3G5A7, was determined by competitive radioimmunoassay using {sup 125}ITHT as a labeled antigen. A standard dose-response curve was demonstrated by Taxol competitive radioimmunoassay. HT and THT were synthesized with 79.9% and 19.5% yield, respectively. The labeling yield of {sup 125}ITHT was 93%. After 7 days, the chemical purity of THT was 96.5% at 4 .deg. C, and 97.5% at 37 .deg. C. After 3 days, {sup 125}ITHT was stable with 94.7% at 4 .deg. C and 93.4% at 37 .deg. C. After 7 days radiochemical purity was diminished to 88.1% at 4 .deg. C and 86.1% at 37 .deg. C. The titer of Taxol monoclonal antibody, 3G5A7, was determined to 1:256. A standard dose-response cure demonstrated good collinearity (R{sup 2}=0.971) as Taxol concentration-dependent manner. Competitive radioimmunoassay using {sup 125

  6. The in vivo pharmacokinetics study of anti-ProGRP(31-98) monoclonal antibody E-B5

    International Nuclear Information System (INIS)

    Objective: Progastrin-releasing peptide(31-98) (ProGRP(31-98) is a specific tumor marker in patients with small cell lung cancer (SCLC). E-B5 antibody against ProGRP(31-98) was produced by China Institute for Radiation Protection. The aim of this study was to explore the 131I labeling methods, stability, immunological activity and biological distribution pattern of E-B5 antibody against ProGRP(31-98). Methods: Chloramine-T method was used for 131I labeling E-B5 antibody. Labeling efficiency, radiochemical purity and stability were estimated by using paper chromatography method. Immunological activity of 131I-E-B5 was detected with cell conjugation assay. After healthy Kunming mice were injected with 131I-E-B5 antibody through tail veil, the biodistribution and pharmacokinetics of 131l-E-B5 antibody in healthy Kunming mice were studied. Continuous images of the nude mice beating SCLC were carried out at different time points after injection of 131I-E-B5 antibody. Continuous variables were expressed as x-bar ± s and compared by t-test with SPSS 13.0 software. Results: The labeling efficiency and radiochemical purity of 131I-E-B5were 90.8%, 99.28%, respectively. The radiochemical purity still maintained above 70% after incubation in water bath at 37 degree C for 24 h. After incubation with healthy serum for 24 h, the radiochemical purity still reached 68.1%. The immunobinding ratios were 71.6% and 33.2% for NCI-H446 cells and A549 cells respectively. The in vivo distribution and elimination of 131I-E-B5 antibody were consistent with a first-order and two-compartment model, t1/2α =0.2 h, t1/2β = 8.35 h. The metabolism of 131I-E-B5 antibody mainly depended on liver and kidney and with rapid elimination in blood. Conclusions: 131I-E-B5 antibody not only has high labeling efficiency and radiochemical purity, but also has good stability and keeps good immunological activity. 131I-E-B5 is a promising agent of radioimmunoimaging and radioimmunotherapy of SCLC. (authors

  7. Vasoactive intestinal peptide receptor scintigraphy in patients with pancreatic adenocarcinomas or neuroendocrine tumours

    International Nuclear Information System (INIS)

    Human adenocarcinomas of the gastroenteropancreatic system overexpress vasoactive intestinal peptide (VIP) receptors and therefore represent logical diagnostic targets for receptor scintigraphy. Using iodine-123 labelled VIP, the newly employed diagnostic procedure termed VIP receptor scintigraphy (VIP-RS) appears to detect tumour tissue, especially pancreatic metastatic tumours, in almost all cases. So far, however, only a single centre has demonstrated convincing positive results. The aim of this study was to compare the sensitivity and specificity of VIP-RS with those of computer tomography (CT) and transabdominal ultrasound in patients with extensive pancreatic metastatic adenocarcinomas and neuroendocrine tumours. VIP was radiolabelled with carrier-free 123I using the chloramine T-method and preparative high-performance liquid chromatography for purification. Patients with metastatic pancreatic (n=12) and colorectal (n=3) carcinomas (adenocarcinoma: n=13, neuroendocrine tumour: n=2) were studied by VIP-RS, CT, ultrasound and, in one case, also by radioligand receptor autoradiography. Carrier-free radioiodinated VIP of maximum specific radioactivity maintained a high biological activity as determined by cAMP formation in receptor-expressing tumour cell lines. Intravenous injection of 123I-VIP did not cause any side-effects. Biodistribution, determined over 24 h, was high in the lungs and low in abdominal organs. Although all patients had extensive metastatic disease as evidenced by CT and ultrasound, VIP-RS was unable to detect either primaries or metastases in these patients. Only in two patients could a significant uptake of radiolabel be detected in organs directly infiltrated by the primary. To exclude false-negative findings, tumour tissue in one patient with a large primary, undetectable by VIP-RS, was analysed by radioligand receptor autoradiography and shown to be receptor positive. Moreover, in vitro receptor determinations showed that pancreatic

  8. Seasonal evaluation of the presence of 46 disinfection by-products throughout a drinking water treatment plant

    International Nuclear Information System (INIS)

    In this work, we studied a total of 46 regulated and non-regulated disinfection by-products (DBPs) including 10 trihalomethanes (THMs), 13 haloacetic acids (HAAs), 6 halonitromethanes (HNMs), 6 haloacetonitriles (HANs) and 11 aldehydes at different points in a drinking water treatment plant (DWTP) and its distribution network. Determining an increased number of compounds and using accurate, sensitive analytical methodologies for new DBPs can be useful to overcome some challenges encountered in the comprehensive assessment of the quality and safety of drinking water. This paper provides a detailed picture of the spatial and seasonal variability of DBP concentrations from raw water to distribution network. Samples were collected on a monthly basis at seven different points in the four seasons of a year to acquire robust data for DBPs and supplementary quality-related water parameters. Only 5 aldehydes and 2 HAAs were found in raw water. Chlorine dioxide caused the formation of 3 new aldehydes (benzaldehyde included), 5 HAAs and chloroform. The concentrations of DBPs present in raw water were up to 6 times higher in the warmer seasons (spring and summer). The sedimentation process further increased their concentrations and caused the formation of three new ones. Sand filtration substantially removed aldehydes and HAAs (15–50%), but increased the levels of THMs, HNMs and HANs by up to 70%. Chloramination raised the levels of 8 aldehydes and 7 HAAs; also, it caused the formation of monoiodoacetic acid, dibromochloromethane, dichloroiodomethane and bromochloroacetonitrile. Therefore, this treatment increases the levels of existing DBPs and leads to the formation of new ones to a greater extent than does chlorine dioxide. Except for 5 aldehydes, the 23 DBPs encountered at the DWTP exit were found at increased concentrations in the warmer seasons (HAAs by about 50% and THMs by 350%). - Highlights: • Occurrence of 46 regulated and non-regulated DBPs through a DWTP was

  9. Disinfection of model indicator organisms in a drinking water pilot plant by using PEROXONE.

    Science.gov (United States)

    Wolfe, R L; Stewart, M H; Liang, S; McGuire, M J

    1989-09-01

    at an applied ozone dosage of 2.0 mg/liter (and a 4-min contact time) when the H2O2/O3 ratio was less than or equal to 0.5. Comparative disinfection experiments indicated that free chlorine was the most potent bactericidal agent, followed (in descending order of effectiveness) by ozone, PEROXONE, and chloramines. These results indicate that the PEROXONE process must be optimized for each source water to achieve microbicidal effectiveness.

  10. A New Group of Disinfection Byproducts in Drinking Water: Trihalo-hydroxy-cyclopentene-diones.

    Science.gov (United States)

    Pan, Yang; Li, Wenbin; Li, Aimin; Zhou, Qing; Shi, Peng; Wang, Ying

    2016-07-19

    We report the detection, synthesis, preparative isolation, structure characterization and identification, and formation of a new group of drinking water disinfection byproducts (DBPs): trihalo-hydroxy-cyclopentene-diones (trihalo-HCDs). With ultra performance liquid chromatography (UPLC)/electrospray ionization-triple quadruple mass spectrometry analyses (full scans, multiple reaction monitoring, and product ion scans) and high-resolution mass spectrometry analyses (full scans), the new group of DBPs was identified with formulae and proposed with structures. However, due to a lack of commercially available standard compounds, structure identification of this new group of DBPs was challenging. 2,4,6-Trihydroxybenzaldehyde was found to be a good precursor for the synthesis of the tribromo species (m/z 345/347/349/351) in the new group of DBPs by reacting with bromine at a 2,4,6-trihydroxybenzaldehyde-to-bromine molar ratio of 1:8. With UPLC/photodiode array analysis (simultaneous 2- and 3-dimensional operations), the new DBP was determined to have a maximum UV absorption at the wavelength of 280 nm. Through isolation with high performance liquid chromatography/UV-triggered collections followed by lyophilization, the pure standard of the new DBP was obtained. Characterized with Fourier transform infrared spectroscopy, the pure standard of the new DBP was finally identified to be tribromo-HCD, and thus the new group of DBPs was identified to be trihalo-HCDs. On the basis of the disclosed structure, formation pathways of tribromo-HCD through reactions of three different precursors and bromine were proposed and partially verified. Moreover, increasing the bromide level in source water shifted the formation of trihalo-HCDs from being more chlorinated to being more brominated; with an increase in the contact time from 1 h to 5 d, the formation of trihalo-HCDs kept increasing in chloramination, whereas they kept decreasing in chlorination; with an increase in the pH from 6

  11. EFFECTS OF SODIUM AND CALCIUM IN LIGNITE ON THE PERFORMANCE OF ACTIVATED CARBON PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Edwin S. Olson; Kurt E. Eylands; Daniel J. Stepan

    2001-12-01

    New federal drinking water regulations have been promulgated to restrict the levels of disinfection by-products (DBPs) in finished public water supplies. DBPs are suspected carcinogens and are formed when organic material is partially oxidized by disinfectants commonly used in the water treatment industry. Additional federal mandates are expected in the near future that will also affect public water suppliers with respect to DBPs. These new federal drinking water regulations may require public water suppliers to adjust treatment practices or incorporate additional treatment operations into their existing treatment trains. Many options have been identified, including membrane processes, granular activated carbon, powered activated carbon (PAC), enhanced coagulation and/or softening, and alternative disinfectants (e.g., chlorine dioxide, ozone, and chloramines). Of the processes being considered, PAC appears to offer an attractive benefit-to-cost advantage for many water treatment plants, particularly small systems (those serving fewer than 10,000 customers). PAC has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters prior to disinfection, thus controlling the formation of regulated DBPs. Many small water systems are currently using PAC for taste and odor control and have the potential to use PAC for controlling DBPs. Activated carbons can be produced from a variety of raw materials, including wood, peat, coconut husks, and numerous types of coal. The Energy & Environmental Research Center (EERC) has been working on the development of a PAC product to remove NOM from surface water supplies to prevent the formation of carcinogenic DBPs during chlorination. During that study, the sodium and calcium content of the lignites showed a significant effect on the sorption capacity of the activated carbon

  12. Distribution of 131I-labeled Bothrops erythromelas venom in mice

    Directory of Open Access Journals (Sweden)

    C.M.L. Vasconcelos

    1998-03-01

    Full Text Available Bothrops erythromelas is responsible for many snake bites in northeastern Brazil. In the present study we determined the in vivo distribution of the venom following its subcutaneous injection into mice. B. erythromelas venom and albumin were labeled individually with 131I by the chloramine T method, and separated in a Sephacryl® S-200 column. The efficiency of labeling was 68%. Male Swiss mice (40-45 g, which had been provided with drinking water containing 0.05% KI over a period of 10 days prior to the experiment, were inoculated dorsally (sc with 0.3 ml (2.35 x 105 cpm/mouse of 131I-venom (N = 42, 131I-albumin or 131I (controls, N = 28 each. Thirty minutes and 1, 3, 6, 12, 18 and 24 h after inoculation, the animals were perfused with 0.85% NaCl and skin and various organs were collected in order to determine radioactivity content. There was a high rate of venom absorption in the skin (51% within the first 30 min compared to albumin (20.1% and free iodine (8.2%. Up to the third hour after injection there was a tendency for venom and albumin to concentrate in the stomach (3rd h, small intestine (3rd h and large intestine (6th h. Both control groups had more radioactivity in the digestive tract, especially in the stomach, but these levels decreased essentially to baseline by 12-18 h postinjection. In the kidneys, the distribution profiles of venom, albumin and iodine were similar. Counts at 30 min postinjection were low in all three groups (1.37, 1.86 and 0.77, respectively, and diminished to essentially 0% by 12-18 h. Albumin tended to concentrate in muscle until the 3rd h postinjection (1.98%. There was a low binding of labeled venom in the liver (<0.54%, thyroid (<0.11% and lungs (<0.08%, and no iodinated venom was detected in brain, heart, diaphragm, spleen or bladder. The low venom binding observed in most internal organs, comparable to that of albumin, suggests that B. erythromelas venom does not specifically target most internal organs

  13. Distribution of 131 I- labeled Bothrops erythromelas venom in mice

    International Nuclear Information System (INIS)

    Bothrops erythromelas is responsible for many snake bites in northeastern Brazil. In the present study we determined the in vivo distribution of the venom following its subcutaneous injection into mice. B. erythromelas venom and albumin were labeled individually with 131 I by the chloramine T method, and separated in a Sephacryl S-200 column. The efficiency of labeling was 68%.Male Swiss mice (40-45 g), which had been provided with drinking water containing 0.05% KI over a period of 10 days prior to the experiment, were inoculated dorsally (sc) with 0.3 ml (2.35 x 105 cpm/mouse) of 131 I-venom (N = 42), 131 -albumin or 131 I (controls, N = 28 each). Thirty minutes and 1,3, 6, 12, 18 and 24 h after inoculation, the animals were perfused with 0.85% Na Cl and skin and various organs were collected in order to determine radioactivity content. There was a high rate of venom absorption int he skin (51%) within the first 30 min compared to albumin (20.1%) and free iodine (8.2%). Up to the third hour after injection there was a tendency for venom and albumin to concentrate in the stomach ( 3 rd h),small intestine (3 rd h) and large intestine (6th h). Both control groups had more radioactivity in the digestive tract, especially in the stomach, but these levels decreased essentially to baseline by 12-18 h postinjection. In the kidneys, the distribution profiles of venom, albumin and iodine were similar. Counts at 30 min postinjection were low in all three groups (1.37, 1.86 and 0.77, respectively), and diminished to essentially 0% by 12-18 h. Albumin tended to concentrate in muscle until the 3 rd h postinjection (1.98%).There was a low binding of labeled venom in the liver (B. erythromelas venom does not specifically target most internal organs. That is, the systemic effects of envenomation ar mainly due to an indirect action. (author)

  14. Comparative Studies on the Radiolabeling and Chromatographic Purification of Some Medically Important Compounds

    International Nuclear Information System (INIS)

    The present thesis comprises five basic chapters: The first chapter includes the main idea of our study and its problems, also includes the aim of the work of our study. The second chapter includes the theoretical consideration of the subject. It deals with the general methods of labeling, factors that influence the integrity of labeled compounds, radionuclides used for diagnostic nuclear medicine, production methods and radioactive properties of 123I, 125I and 131I. It includes also the techniques used for the preparation of the radioiodinated compounds especially the electrophilic radioiodination technique. This chapter deals also with the medical imaging, techniques of diagnostic nuclear medicine and the purification of radioiodinated compounds using different chromatographic techniques. Since these radioiodinated compounds are used for diagnosis and therapeutic treatment of human diseases, quality control tests such as determination of chemical purity, radionuclidic purity, radiochemical purity, sterility, pyrogenicity and biodistribution are performed to ensure the purity, the safety and efficiency of these products for the intended nuclear medicine application. The third chapter describes the experimental section; comprising chemicals, reagents, the radionuclides, the equipments and the counting systems used in the study. It describes the electrophilic radioiodination using chloramine-T (CAT), iodogen and lactoperoxidase oxidizing agents and the factors affecting the radiochemical yield of the radioiodination of histamine and L-tyrosine methyl ester such as substrate concentration, ph of the medium, reaction time, temperature and stability of the labeled product. This chapter also includes the techniques used in the Purification of radioiodinated compounds, including paper electrophoresis, thin layer chromatography (TLC), Poly acrylamide-acrylic acid resin [P(AAm-AA) resin] and high performance liquid chromatography (HPLC), in addition, the quality control

  15. A radioimmunoassay for erythropoietin: serum levels in normal human subjects and patients with hemopoietic disorders

    Energy Technology Data Exchange (ETDEWEB)

    Rege, A.B.; Brookins, J.; Fisher, J.W.

    1982-12-01

    An RIA for Ep has been developed that is highly sensitive and specific. A homogeneous Ep preparation was labeled with /sup 125/I by the chloramine-T method to a specific activity of 90 to 136 ..mu..Ci/..mu..g and immunoreactivity of 80%. Ep antiserum, which was produced to a human urinary Ep preparation (80 U/mg of protein), was adsorbed with normal human urinary and serum proteins without any loss in sensitivity of the RIA to increase the specificity of the assay. A good correlation was seen between the RIA and the exhypoxic polycythemic mouse assay (corr. coef. 0.967; slope 1.05 and ''y'' intercept 0.75). Ep titers in sera from 175 hematologically normal human subjects exhibited a normal frequency distribution and ranged between 5.8 and 36.6 mU/ml with a mean of 14.9 +/- 4.7 (S.D.) and median of 14.3. Serum Ep titers were markedly elevated in seven patients with aplastic anemia and one patient with pure red cell aplasia (1350 to 20,640 mU/ml) and were lower than normal in two patients with polycythemia vera (8.1 and 9.4 mU/ml). The serum Ep titers in a prenephrectomy patient with chronic glomerulonephritis (31.1 mU/ml) decreased to below normal levels (9.04 mU/ml) after nephrectomy. The cord serum erythropoietin titers in 10 IDM (90.82 +/- 134.1 (S.D.) mu/ml) returned to values within the normal range (13.86 +/- 5.55) on day 3 after birth, suggesting the utility of the RIA in elucidating the role of hypoxia and/or insulin in increased erythropoiesis in IDM. The serum Ep titers in patients with anemias and polycythemias were compared to those of normal human subjects and agreed well with pathophysiologic mechanisms of these hemopoietic disorders, confirming the validity of the RIA.

  16. A radioimmunoassay for erythropoietin: serum levels in normal human subjects and patients with hemopoietic disorders

    Energy Technology Data Exchange (ETDEWEB)

    Rege, A.B.; Brookins, J.; Fisher, J.W.

    1982-12-01

    An RIA for Ep has been developed that is highly sensitive and specific. A homogeneous Ep preparation was labeled with /sup 125/I by the chloramine-T method to a specific activity of 90 to 136 micro Ci/microgram and immunoreactivity of 80%. Ep antiserum, which was produced to a human urinary Ep preparation (80 U/mg of protein), was adsorbed with normal human urinary and serum proteins without any loss in sensitivity of the RIA to increase the specificity of the assay. A good correlation was seen between the RIA and the exhypoxic polycythemic mouse assay (corr. coef. 0.967; slope 1.05 and y intercept 0.75). Ep titers in sera from 175 hematologically normal human subjects exhibited a normal frequency distribution and ranged between 5.8 and 36.6 mU/ml with a mean of 14.9 +/- 4.7 (S.D.) and median of 14.3 Serum Ep titers were markedly elevated in seven patients with aplastic anemia and one patient with pure red cell aplasia (1350 to 20,640 mU/ml) and were lower than normal in two patients with polycythemia vera (8.1 and 9.4 mU/ml). The serum Ep titers in a prenephrectomy patient with chronic glomerulonephritis (32.1 mU/ml) decreased to below normal levels (9.04 mU/ml) after nephrectomy. The cord serum erythropoietin titers in 10 IDM (90.82 +/- 134.1 (S.D.) mu/ml) returned to values within the normal range (13.86 +/- 5.55) on day 3 after birth, suggesting the utility of the RIA in elucidating the role of hypoxia and/or insulin in increased erythropoiesis in IDM. The serum Ep titers in patients with anemias and polycythemias were compared to those of normal human subjects and agreed well with pathophysiologic mechanisms of these hemopoietic disorders, confirming the validity of the RIA.

  17. Functional expression of a single-chain antibody to ErbB-2 in plants and cell-free systems

    Directory of Open Access Journals (Sweden)

    Benevolo Maria

    2006-09-01

    Full Text Available Abstract Background Aberrant signaling by ErbB-2 (HER 2, Neu, a member of the human Epidermal Growth Factor (EGF receptor family, is associated with an aggressive clinical behaviour of carcinomas, particularly breast tumors. Antibodies targeting the ErbB-2 pathway are a preferred therapeutic option for patients with advanced breast cancer, but a worldwide deficit in the manufacturing capacities of mammalian cell bioreactors is foreseen. Methods Herein, we describe a multi-platform approach for the production of recombinant Single chain Fragments of antibody variable regions (ScFvs to ErbB-2 that involves their functional expression in (a bacteria, (b transient as well as stable transgenic tobacco plants, and (c a newly developed cell-free transcription-translation system. Results An ScFv (ScFv800E6 was selected by cloning immunoglobulin sequences from murine hybridomas, and was expressed and fully functional in all the expression platforms, thereby representing the first ScFv to ErbB-2 produced in hosts other than bacteria and yeast. ScFv800E6 was optimized with respect to redox synthesis conditions. Different tags were introduced flanking the ScFv800E6 backbone, with and without spacer arms, including a novel Strep II tag that outperforms conventional streptavidin-based detection systems. ScFv800E6 was resistant to standard chemical radiolabeling procedures (i.e. Chloramine T, displayed a binding ability extremely similar to that of the parental monovalent Fab' fragment, as well as a flow cytometry performance and an equilibrium binding affinity (Ka approximately 2 × 108 M-1 only slightly lower than those of the parental bivalent antibody, suggesting that its binding site is conserved as compared to that of the parental antibody molecule. ScFv800E6 was found to be compatible with routine reagents for immunohistochemical staining. Conclusion ScFv800E6 is a useful reagent for in vitro biochemical and immunodiagnostic applications in oncology

  18. Improved iodine radiolabels for monoclonal antibody therapy.

    Science.gov (United States)

    Stein, Rhona; Govindan, Serengulam V; Mattes, M Jules; Chen, Susan; Reed, Linda; Newsome, Guy; McBride, Bill J; Griffiths, Gary L; Hansen, Hans J; Goldenberg, David M

    2003-01-01

    A major disadvantage of (131)iodine (I)-labeled monoclonal antibodies (MAbs) for radioimmunotherapy has been the rapid diffusion of iodotyrosine from target cells after internalization and catabolism of the radioiodinated MAbs. We recently reported that a radioiodinated, diethylenetriaminepentaacetic acid-appended peptide, designated immunomedics' residualizing peptide 1 (IMP-R1), was a residualizing iodine label that overcame many of the limitations that had impeded the development of residualizing iodine for clinical use. To determine the factors governing the therapeutic index of the labeled MAb, as well as the factors required for production of radioiodinated MAb in high yield and with high specific activity, variations in the peptide structure of IMP-R1 were evaluated. A series of radioiodinated, diethylenetriaminepentaacetic acid-appended peptide moieties (IMP-R1 through IMP-R8) that differed in overall hydrophilicity and charge were compared. Radioiodinations of the peptides followed by conjugations to disulfide-reduced RS7 (an anti-epithelial glycoprotein-1 MAb) furnished radioimmunoconjugates in good overall incorporations, with immunoreactivities comparable to that of directly radioiodinated RS7. Specific activities of up to 8 mCi/mg and yields > 80% have been achieved. In vitro processing experiments showed marked increases in radioiodine retention with all of the adducts; radioiodine retention at 45 h was up to 86% greater in cells than with directly iodinated RS7. Each of the (125)I-peptide-RS7 conjugates was compared with (131)I-RS7 (labeled by the chloramine-T method) in paired-label biodistribution studies in nude mice bearing human lung tumor xenografts. All of the residualizing substrates exhibited significantly enhanced retention in tumor in comparison to directly radioiodinated RS7, but the nontarget uptakes differed significantly among the residualizing labels. The best labels were IMP-R4 and IMP-R8, showing superior tumor-to-non-tumor ratios

  19. Distribution of {sup 131} I- labeled Bothrops erythromelas venom in mice

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, C.M.L.; Valenca, R.C.; Araujo, E.A. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia; Modesto, J.C.A.; Pontes, M.M.; Guarnieri, M.C. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Zoologia; Brazil, T.K. [Bahia Univ., Salvador, BA (Brazil). Inst. de Biologia

    1998-03-01

    Bothrops erythromelas is responsible for many snake bites in northeastern Brazil. In the present study we determined the in vivo distribution of the venom following its subcutaneous injection into mice. B. erythromelas venom and albumin were labeled individually with {sup 131} I by the chloramine T method, and separated in a Sephacryl S-200 column. The efficiency of labeling was 68%.Male Swiss mice (40-45 g), which had been provided with drinking water containing 0.05% KI over a period of 10 days prior to the experiment, were inoculated dorsally (sc) with 0.3 ml (2.35 x 10{sup 5} cpm/mouse) of {sup 131} I-venom (N = 42), {sup 131} -albumin or {sup 131} I (controls, N = 28 each). Thirty minutes and 1,3, 6, 12, 18 and 24 h after inoculation, the animals were perfused with 0.85% Na Cl and skin and various organs were collected in order to determine radioactivity content. There was a high rate of venom absorption int he skin (51%) within the first 30 min compared to albumin (20.1%) and free iodine (8.2%). Up to the third hour after injection there was a tendency for venom and albumin to concentrate in the stomach ( 3 rd h),small intestine (3 rd h) and large intestine (6th h). Both control groups had more radioactivity in the digestive tract, especially in the stomach, but these levels decreased essentially to baseline by 12-18 h postinjection. In the kidneys, the distribution profiles of venom, albumin and iodine were similar. Counts at 30 min postinjection were low in all three groups (1.37, 1.86 and 0.77, respectively), and diminished to essentially 0% by 12-18 h. Albumin tended to concentrate in muscle until the 3 rd h postinjection (1.98%).There was a low binding of labeled venom in the liver (B. erythromelas venom does not specifically target most internal organs). That is, the systemic effects of envenomation ar mainly due to an indirect action. (author) 14 refs., 2 figs.

  20. Monoclonal antibody RM2 as a potential ligand for a new immunotracer for prostate cancer imaging

    International Nuclear Information System (INIS)

    Objectives: To investigate the potential of monoclonal antibody (mAb) RM2 as a ligand for a radioimmunotracer for prostate cancer imaging. Methods: Labeling was conducted with mAb RM2 and 125I using the chloramine-T method. The cell study was conducted with PC-3 and LNCaP, which are prostate cancer cell lines, and MCF-7, which is a breast cancer cell line. The cells were treated or untreated with unlabeled mAb RM2 to block the haptoglobin-β chains expressed on the surface of the prostate cancer cells. 125I-mAb RM2 was added into the cell culture media and cellular uptake of 125I-mAb RM2 was evaluated at 1, 3 and 6 hours of incubation. For the in vivo biodistribution study, PC-3 cells were implanted in athymic male mice. The animals were injected intravenously with 125I-mAb RM2. At 24, 48 and 72 hours after tracer injection, the animals were sacrificed and the activity levels of blood and tissue samples were determined. Results: The uptake of 125I-mAb RM2 in the PC-3 and LNCaP cells increased according to the incubation time, while the uptake of 125I-mAb RM2 in MCF-7 cells did not show any increase up to 6 hours. The increase of 125I-RM2 uptake was not observed when the PC-3 and LNCaP cells were pre-treated with unlabeled RM2. In the biodistribution studies, 125I-mAb RM2 showed marked uptake into the implanted PC-3 cells. In PC-3 tumor-bearing mice, the tumor muscle ratio of 125I-RM2 was increased for up to 72 hours in a time-dependent manner. Conclusions: 125I-mAb RM2 showed excellent prostate cancer cell targeting in vitro and in vivo. Therefore, mAb RM2 seems to be a potential candidate for an immunoligand for prostate cancer imaging.

  1. Synthesis and evaluation of iodine-123 labelled tricyclic tropanes as radioligands for the serotonin transporter

    Energy Technology Data Exchange (ETDEWEB)

    Quinlivan, Mitchell; Mattner, Filomena; Papazian, Vahan; Zhou, Jia; Katsifis, Andrew; Emond, Patrick; Chalon, Sylvie; Kozikowski, Alan; Guilloteau, Denis; Kassiou, Michael E-mail: mkassiou@med.usyd.edu.au

    2003-10-01

    The tricyclic tropane analogues (1S,3S,6R,10S)-(Z)-10-(benzoyloxymethyl)-9-(3-chloro-4-iodobenzylidene)-7 -azatricyclo[4.3.1.0{sup 3,7}]decane, 1, and (1S,3S,6R,10S)-(Z)-9-(3-chloro-4-iodobenzylidene)-7-azatricyclo[4.3.1.0{sup 3,7}] = decane-10-carboxylic acid methyl ester, 2, have been shown to be potent and selective serotonin transporter (SERT) ligands. They possess nanomolar affinity for the SERT (Ki = 0.06 nM and 1.8 nM respectively) and are suitable for radiolabelling using iodine-123. In the present study we prepared [{sup 123}I]1 and [{sup 123}I]2 from the appropriate tributylstannane precursors using acidic media with chloramine-T as the oxidising agent. The radiochemical yield obtained for [{sup 123}I]1 varied between 50-60% while for [{sup 123}I]2 the range was 65-80%. Both radioligands were obtained with radiochemical purity > 97% and specific activity estimated to be > 185 GBq/{mu}mol. The biodistribution of [{sup 123}I]1 demonstrated low degree of brain penetration at 5 min (0.14%ID/g) with a homogenous distribution. The radioactivity cleared quickly from all brain regions with no preferential localization. In comparison, [{sup 123}I]2 demonstrated on average a higher brain uptake at 5 min (0.5%ID/g). However the distribution of radioactivity was homogenous and cleared to levels similar to [{sup 123}I]1 at 1 hr post-injection. Pre-administration of citalopram failed to show any significant inhibition of [{sup 123}I]2 uptake in the rat brain. The high lipophilicity of 1 and 2 (HPLC-derived log P{sub 7.4} values of 6.41 and 4.25 respectively) and in vivo metabolism, seen by high thyroid uptake would explain the absence of any specific binding observed in the rat brain. In view of these results [{sup 123}I]1 and [{sup 123}I]2 do not appear to be suitable radioligands for in vivo studies of the SERT.

  2. Electrodegradation of the Acid Green 28 dye using Ti/β-PbO2 and Ti-Pt/β-PbO2 anodes.

    Science.gov (United States)

    Irikura, Kallyni; Bocchi, Nerilso; Rocha-Filho, Romeu C; Biaggio, Sonia R; Iniesta, Jesús; Montiel, Vicente

    2016-12-01

    The statistical Response Surface Methodology (RSM) is applied to investigate the effect of different parameters (current density, j, NaCl concentration, [NaCl], pH, and temperature, θ) and their interactions on the electrochemical degradation of the Acid Green (AG) 28 dye using a Ti/β-PbO2 or Ti-Pt/β-PbO2 anode in a filter-press reactor. LC/MS is employed to identify intermediate compounds. For both anodes, the best experimental conditions are j = 50 mA cm(-2), [NaCl] = 1.5 g L(-1), pH = 5, and θ = 25 °C. After 3 h of electrolysis, a dye solution treated under these conditions presents the following parameters: electric charge per unit volume of the electrolyzed solution required for 90% decolorization (Q(90)) of 0.34-0.37 A h L(-1), %COD removal of ∼100%, specific energy consumption of 18-20 kW h m(-3), and %TOC removal of 32-33%. No loss of the β-PbO2 film is observed during all the experiments. The β-PbO2 films present excellent stability for solutions with pH ≥ 5 ([Pb(2+)] < 0.5 mg L(-1)). Chloroform is the only volatile organic halo compound present in the treated solution under those optimized conditions. Hydroxylated anthraquinone derivatives, aromatic chloramines, and naphthoquinones are formed during the electrolyses. The Ti/β-PbO2 and Ti-Pt/β-PbO2 anodes show significantly better performance than a commercial DSA anode for the electrochemical degradation of the AG 28 dye. The Ti/β-PbO2 anode, prepared as described in this work, is an excellent option for the treatment of textile effluents because of its low cost of fabrication and good performance.

  3. [Comparison of susceptibility of spores of Bacillus subtilis and Czech strains of Clostridium difficile to disinfectants].

    Science.gov (United States)

    Votava, M; Slitrová, B

    2009-02-01

    An important factor in the prevention of nosocomial outbreaks caused by Clostridium difficile ribotype 027 is the disinfection of a patient environment by reliable sporicidal disinfectants. Sporicidal activity of particular agents is tested on spores of Bacillus subtilis. Questions are brought up if the disinfectant which works on B. subtilis spores will be equally effective on the spores of C. difficile. Therefore we have compared the effects of five disinfectants available on the Czech market on the spores of collection strains of both microbes and on the spores of ten C. difficile field strains isolated from feces of hospitalized patients. The effective substances were: disinfectant No. 1 chloramine B, No. 2 chlorine dioxide, No. 3 formaldehyde and ethan-2-dion, No. 4 peracetic and acetic acids and hydrogen peroxide, No. 5 ethanol and propan-2-ol. The testing was performed using the dilution neutralization method according to (SN EN 13704, the agent reducing the number of spores by more than 3 orders was considered sporicidal. In addition to the standard time 60 min a 15-minutes exposition was used and the effect was tested also under the protein burden. Disinfectant No. 1 showed better effect on the C. difficile than B. subtilis spores, even in lower (1%) concentration. Similarly, the sensitivity of the C. difficile spores to disinfectants No. 2 and 3 was somewhat higher. The sporicidity of the disinfectant No. 4 was so high that it reduced the number of spores of all strains within 15 minutes by more than 4 orders; possible difference in the susceptibility of spores was not observed. Whereas the disinfectant No. 5 was not reliably effective on the spores of B. subtilis, surprisingly it showed the sporicidal effect on the spores of field C. difficile strains. We conclude that spores of field C. difficile strains in particular turned out to be more sensitive to disinfectants than the spores of the collection strain ofB. subtilis. Therefore B. subtilis remains

  4. Experimental study of radiotargeting-therapy with small molecular polypeptide in nude mice bearing lung adenocarcinoma

    International Nuclear Information System (INIS)

    Background: Integrin signal transduction pathways provide an important basis for molecular targeting therapy of cancer in tumor growth, infiltration and transfer. Existing research data have shown that small molecular peptide labeled with radionuclide has good clinical application prospects, but the successful researches on lung cancer have not been reported so far. It is considered that the main reason is the lack of small molecule peptide for specific targeting lung cancer. Purpose: Based on the small molecular peptide cNGQGEQc for specifically identifying integrin α3 and β1 found previously, polypeptide cNGQGEQc is selected and radiolabelled with 131I. And the inhibitory effect of 131I-cNGQGEQc in nude mice bearing lung adenocarcinoma is observed. Methods: The coupling of cNGQGEQc and tyrosine was done in the processing of solid phase synthesis of small molecular peptide. Chloramine-T method was used for radiolabelling of cNGQGEQc with 131I. Twenty nude mice bearing NCI-H1975 were built and randomly divided into four groups with five mice in each group, including the group of 131I-cNGQGEQc, the group of 131I-cNAQAEQc, the group of 131I and the saline control group. The general condition was observed in nude mice bearing tumor after tail vein injection of corresponding drugs. And the tumor sizes after grafting were measured per 3 days in 30 days. The inhibitory rate of tumor in each group was calculated. Results: The labeling efficiencies of 131I-cNGQGEQc and 131I-cNAQAEQc were greater than 90% with the radiochemical purity of more than 95%, and 131I-cNGQGEQc had obvious inhibitory effect for transplantation tumor in nude mice bearing NCI-H1975 adenocarcinoma of lung. After a treatment for 30 days the tumor inhibitory rates were 60.93% for the group of 131I-cNGQGEQc, 11.63% for the group of 131I-cNAQAEQ and 10.70% for the group of 131I. Conclusion: 131I-cNGQGEQC has a good affinity and effective inhibit effect for the NCI-H1975 lung adenocarcinoma. Integrin is

  5. Acute Toxicity Evaluation of Ninety-one Pesticides to Silkworm%91种农药制剂对家蚕的急性毒性研究

    Institute of Scientific and Technical Information of China (English)

    孙新友; 袁善奎; 林荣华; 王晓军; 瞿唯钢; 张燕; 高希武; 姜天明

    2011-01-01

    The acute toxicity of ninety-one pesticides to silkworm, Bombyx mori L., was evaluated in laboratory using the intake toxic leaf method, the toxic grades were compartmentalizedaccording to the results and the safety evaluation was made for these pesticides. The LC50 values of thirty pesticides were lower than 0.5mg/kg mulberry (belonged to extremely toxic grade), including emamectin benzoate, abamectin, beta-cypermethrin, bifenthrin, tebufenozide and triazophos etc. ; The LC50 values of fifteen pesticides were between 0.5-20mg/kg mulberry (belonged to high toxic grade), including carbosulfan, chlorfenapyr, triflumuron, fipronil, buprofezin, chloramine phosphorus and trichlorfon etc. ; that of ninety pesticides were between 20-200mg/kg mulberry (belonged to moderate toxic grade) ; That of twenty-seven pesticides were higher than 200mg/kg mulberry (belonged to low toxic grade).%为评价农药对家蚕的环境安全性,作者采用毒叶饲喂法在室内测定了91种农药对家蚕(BombyxmoriL.)的急性毒性,并根据其毒性范围进行分级.结果表明:有30种药剂的LC50〈0.5mg/kg桑叶,属于剧毒级,包括甲氨基阿维菌素苯甲酸盐、阿维菌素、高效氯氰菊酯、联苯菊酯、虫酰肼、三唑磷等;有15种药剂的LC50为0.5~20mg/kg桑叶,属于高毒级.如丁硫克百威、虫螨腈、杀铃脲、氟虫腈、噻嗪酮、高渗氯胺磷、敌百虫;19种药剂的LC50为20~200mg/kg桑叶,属于中等毒级;27种药剂LC50〉200

  6. Research on variation of water quality chemical stability during the water treatment process%水质化学稳定性沿工艺流程变化研究

    Institute of Scientific and Technical Information of China (English)

    张庆; 梅红

    2012-01-01

    通过研究水质化学稳定性随水处理工艺流程的变化,探讨影响水质化学稳定性的因素.结果表明:水处理中碱度消耗工艺(混凝、生物活性炭和臭氧氧化工艺)均使水质化学稳定性下降.生物活性炭滤池运行初期生物膜未形成或尚不成熟时,对水质化学稳定性基本无影响,相反,初期活性炭表面金属溶出还可能改善水质化学稳定性.氯胺消毒基本不影响水质化学稳定性,投加NaClO可提高水质化学稳定性.混凝剂投加后增加水中无机阴离子(SO42-和Cl-),增加水体对管道的腐蚀倾向.%Through studying the variation of water quality chemical stability during the water treatment process, the factors influencing the water quality chemical stability were discussed. The results showed that: alkalinity consumption processes (coagulation, biological activated carbon and ozone oxidation) deteriorated the water quality chemical stability. There was almost no influence on water quality chemical stability when biofilm was not formed or not yet mature in the early operation period of biological activated carbon filter. On the contrary, the metal precipitation on the surface of the activated carbon happened in the initial stage might improve the water quality chemical stability. The water quality chemical stability was almost not influenced by chloramines disinfection, but was improved by adding NaClO. As coagulant dosing increased the concentration of the dissolved inorganic anions (SO24- and Cl-), the corrosion tendency of the iron pipe was also aggravated.

  7. Study on Disinfection and Anti-microbial Technologies for Drinking Water%饮用水的消毒及杀菌技术研究

    Institute of Scientific and Technical Information of China (English)

    朱琨; 伏小勇

    2001-01-01

    饮用水处理消毒过程中可产生一系列致癌物质,主要是氯与水中的有机物和其它化学成分反应的结果,其中典型产物有三氯甲烷.通过对常用消毒剂液氯,臭氧,二氧化氯,高锰酸钾,氯胺及过氧化氢的实验对比,证明二氧化氯是高效,方便,廉价的消毒剂.它不仅对一般病原菌类有明显的抑制和杀菌作用,对清除难以灭杀的潜原性病毒也有理想的效果.在净化水中石油类有机物时,二氧化氯的效果受到反应时间,注入方式和pH值的影响.%Disinfection by-products produced by the reaction betweenchlorine and dissolved organic compounds and other chemicals are considered as a worrying problem in the drinking water treatment process since a series of mutagenic carcinogen substances are formed including trihalomethanes (THMs). Among the tested disinfectants (chlorine, ozone, chlorine dioxide, potassium permanganate, chloramines and hydrogen peroxide etc.), chlorine dioxide has proved to be the most feasible and effective oxidant for drinking water treatment and removal of pathogens due to its oxidation efficiency, low cost and simple way of utilization. A series of experiments indicate that chlorine dioxide can significantly restrain production of trihalomethanes (THMs) and control bacteria growth particularly for Cryptosporidium oocysts.The experiments verified that both ozone and chlorine dioxide are absolutely vital to ensure that any microorganisms arising from fecal contamination of water storage are destroyed. The paper discusses oxidation capacity of chlorine dioxide, especially for removing petroleum compounds, which is affected by reaction time, gas injection way, and pH of treated water.

  8. Preparation of the radiopharmaceutical {sup 131}I-Anti-CD20 for the treatment of lymphomas; Preparacion del radiofarmaco {sup 131}I-Anti-CD20 para el tratamiento de linfomas

    Energy Technology Data Exchange (ETDEWEB)

    Pantoja H, I.E

    2004-07-01

    At the present time they are considered to the lymphomas like a problem of first magnitude since has happened it is necessary to be the fifth cancer cause in the world. Different treatments focused to the lymphoma like the chemotherapy and the radiotherapy, have been employees to counteract the No-Hodgkin lymphoma, without these they don't exclude the healthy tissue of the toxicity. It is for it that is taking a new direction with the employment of the directed radioimmunotherapy since this it allows to kill wicked cells selectively with radiation dose joined to the apoptosis and cytotoxicity induced by the own one bio molecule. The radioimmunotherapy with radiolabelled antibodies directed to the surface antigen CD20 represents a new modality for the treatment of No-Hodgkin lymphoma and potentially other illnesses. In this work the parameters of optimization are presented for the preparation, control of quality and evaluation of the stability in vitro and in vivo of the monoclonal antibody anti-CD20 labelled with {sup 131} I for the treatment of No-Hodgkin lymphoma. The anti-CD20 labelled by the chloramine-T method with high radiochemical purity (>98%), it is stable in solution for but of a half life of the radionuclide (8.04 days) The {sup 131} I-anti-CD20 doesn't present dehalogenation in vitro (human serum) during 24 h of incubation at 37 C. According to the tests carried out to establish the immunoreactivity, a percentage of union to cells was obtained (B lymphocytes) bigger to 30%. The biodistribution in mice balb/c one hour after their administration, it shows that there is not high reception in mucous neither kidneys, what indicates that the complex is stable in vivo. In conclusion, the radiopharmaceutical {sup 131} I-anti-CD20 was obtained in sterile injectable solution and free of pyrogens with a radiochemical purity bigger to 98% and a specific activity of 296 MBq. The radiolabelled molecule maintains its biological recognition for the receiving

  9. Preparation of the radiopharmaceutical 131I-Anti-CD20 for the treatment of lymphomas

    International Nuclear Information System (INIS)

    At the present time they are considered to the lymphomas like a problem of first magnitude since has happened it is necessary to be the fifth cancer cause in the world. Different treatments focused to the lymphoma like the chemotherapy and the radiotherapy, have been employees to counteract the No-Hodgkin lymphoma, without these they don't exclude the healthy tissue of the toxicity. It is for it that is taking a new direction with the employment of the directed radioimmunotherapy since this it allows to kill wicked cells selectively with radiation dose joined to the apoptosis and cytotoxicity induced by the own one bio molecule. The radioimmunotherapy with radiolabelled antibodies directed to the surface antigen CD20 represents a new modality for the treatment of No-Hodgkin lymphoma and potentially other illnesses. In this work the parameters of optimization are presented for the preparation, control of quality and evaluation of the stability in vitro and in vivo of the monoclonal antibody anti-CD20 labelled with 131 I for the treatment of No-Hodgkin lymphoma. The anti-CD20 labelled by the chloramine-T method with high radiochemical purity (>98%), it is stable in solution for but of a half life of the radionuclide (8.04 days) The 131 I-anti-CD20 doesn't present dehalogenation in vitro (human serum) during 24 h of incubation at 37 C. According to the tests carried out to establish the immunoreactivity, a percentage of union to cells was obtained (B lymphocytes) bigger to 30%. The biodistribution in mice balb/c one hour after their administration, it shows that there is not high reception in mucous neither kidneys, what indicates that the complex is stable in vivo. In conclusion, the radiopharmaceutical 131 I-anti-CD20 was obtained in sterile injectable solution and free of pyrogens with a radiochemical purity bigger to 98% and a specific activity of 296 MBq. The radiolabelled molecule maintains its biological recognition for the receiving CD20 highly expressed in

  10. Influence of Organic Nitrogen Compounds on Chlorine Disinfection%有机氮类化合物对氯消毒影响研究

    Institute of Scientific and Technical Information of China (English)

    徐华; 杨艳玲; 王花平; 梁贞淑

    2012-01-01

    受污染饮用水水源中都含多种有机氮类化合物,会对氯消毒效果产生影响.试验采用有机氮类化合物甘氨酸、亮氨酸、赖氨酸、天冬氨酸、半胱氨酸和甲胺,研究了有机氮类化合物浓度和pH值对消毒效果的影响.结果表明,有机氮类化合物都会和自由氯迅速反应生成大量的有机氯胺,使消毒效果显著下降;不同有机氮类化合物对氯消毒效果的影响有很大差异,半胱氨酸的影响最为明显,使得氯几乎丧失消毒能力.因此,对有机氮类化合物的含量和去除应考虑改善氯的投加方式或氯消毒工艺,建立安全有效的消毒方法.%Many organic nitrogen compounds are contained in polluted resource of drinking water, which seriously influence on chlorine disinfection. Typical organic nitrogen compounds including glycine, leucine, lysine, aspartic acid, cysteine, and methylamine were applied. Influences of organic nitrogen compound dosage and pH on disinfection effects are investigated. Results show that many organic chloramines are produced by prompt action of organic nitrogen compounds and free chlorine to decrease disinfection effects pronounced. Influences on chlorine disinfection effects are different through different organic nitrogen compounds. Influence of cysteine is most obvious to cause chlorine losing disinfection capacity. Therefore, contents and removal of organic nitrogen compounds must be attached. The chlorine dosing mode and chlorine disinfection process can be improved and the effective safe disinfection method must be established.

  11. Photolytic removal of DBPs by medium pressure UV in swimming pool water

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Kamilla M.S. [Department of Environmental Engineering, Technical University of Denmark (Denmark); Zortea, Raissa [Department of Land, Environment and Geotechnology Engineering, Polytechnic University of Turin (Italy); Piketty, Aurelia [Institute of Chemistry, Industrial and Chemical Engineering and Technology (INP-ENCIACET), National Polytechnic Institute of Toulouse (France); Vega, Sergio Rodriguez [Chemical Engineering, Complutense University of Madrid (Spain); Andersen, Henrik Rasmus, E-mail: Henrik@ndersen.net [Department of Environmental Engineering, Technical University of Denmark (Denmark)

    2013-01-15

    Medium pressure UV is used for controlling the concentration of combined chlorine (chloramines) in many public swimming pools. Little is known about the fate of other disinfection by-products (DBPs) in UV treatment. Photolysis by medium pressure UV treatment was investigated for 12 DBPs reported to be found in swimming pool water: chloroform, bromodichloromethane, dibromochloromethane, bromoform, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetronitrile, trichloroacetonitrile, trichloronitromethane, dichloropropanone, trichloropropanone, and chloral hydrate. First order photolysis constants ranged 26-fold from 0.020 min{sup −1} for chloroform to 0.523 min{sup −1} for trichloronitromethane. The rate constants generally increased with bromine substitution. Using the UV removal of combined chlorine as an actinometer, the rate constants were recalculated to actual treatment doses of UV applied in a swimming pool. In an investigated public pool the UV dose was equivalent to an applied electrical energy of 1.34 kWh m{sup −3} d{sup −1} and the UV dose required to removed 90% of trichloronitromethane was 0.4 kWh m{sup −3} d{sup −1}, while 2.6 kWh m{sup −3} d{sup −1} was required for chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes ranged from 0.6 to 3.1 kWh m{sup −3} d{sup −1}. It was predicted thus that a beneficial side-effect of applying UV for removing combined chlorine from the pool water could be a significant removal of trichloronitromethane, chloral hydrate and the bromine containing haloacetonitriles and trihalomethanes. - Highlights: ► UV irradiation is able to degrade all 12 investigated disinfection by-products. ► Bromine species are easier to remove than their chlorinated analogues. ► UV dose used for combined chlorine was comparable with doses required for DBP removal. ► Significant removal of some disinfection by-products in swimming pools is indicated.

  12. Seasonal evaluation of the presence of 46 disinfection by-products throughout a drinking water treatment plant

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, Maria; Montesinos, Isabel; Cardador, M.J.; Silva, Manuel; Gallego, Mercedes, E-mail: mercedes.gallego@uco.es

    2015-06-01

    In this work, we studied a total of 46 regulated and non-regulated disinfection by-products (DBPs) including 10 trihalomethanes (THMs), 13 haloacetic acids (HAAs), 6 halonitromethanes (HNMs), 6 haloacetonitriles (HANs) and 11 aldehydes at different points in a drinking water treatment plant (DWTP) and its distribution network. Determining an increased number of compounds and using accurate, sensitive analytical methodologies for new DBPs can be useful to overcome some challenges encountered in the comprehensive assessment of the quality and safety of drinking water. This paper provides a detailed picture of the spatial and seasonal variability of DBP concentrations from raw water to distribution network. Samples were collected on a monthly basis at seven different points in the four seasons of a year to acquire robust data for DBPs and supplementary quality-related water parameters. Only 5 aldehydes and 2 HAAs were found in raw water. Chlorine dioxide caused the formation of 3 new aldehydes (benzaldehyde included), 5 HAAs and chloroform. The concentrations of DBPs present in raw water were up to 6 times higher in the warmer seasons (spring and summer). The sedimentation process further increased their concentrations and caused the formation of three new ones. Sand filtration substantially removed aldehydes and HAAs (15–50%), but increased the levels of THMs, HNMs and HANs by up to 70%. Chloramination raised the levels of 8 aldehydes and 7 HAAs; also, it caused the formation of monoiodoacetic acid, dibromochloromethane, dichloroiodomethane and bromochloroacetonitrile. Therefore, this treatment increases the levels of existing DBPs and leads to the formation of new ones to a greater extent than does chlorine dioxide. Except for 5 aldehydes, the 23 DBPs encountered at the DWTP exit were found at increased concentrations in the warmer seasons (HAAs by about 50% and THMs by 350%). - Highlights: • Occurrence of 46 regulated and non-regulated DBPs through a DWTP was

  13. APPLICATION OF THE COMBINED UV AND CHLORINE DISINFECTION IN WATER PLANT%紫外线和化合氯联合消毒在水厂的应用研究

    Institute of Scientific and Technical Information of China (English)

    潘晓; 王祥勇; 陈洪斌

    2012-01-01

    Based on the pilot and productive ultraviolet disinfection devices in a water plant in the south China, we studied the combined UV and chlorine disinfection effect on biological activated carbon effluent, evaluated the effect of UV disinfection system in the water treatment plant. Studies have shown that the removal rate of biological activated carbon effluent bacteria number could reach 2.6 Ig in 480 J/m2 UV dose condition, but UV have no continuous sterilization. UV disinfection system in water treatment plant generally performed wells, the total number of bacteria from the combined UV and chlorine disinfection system effluent was 0, ultraviolet disinfection efficiency reduced after a long time running. Biological activated carbon process have better control effect on chloramines disinfection by-products, U V disinfection does not increase the chlorine disinfection by-products formation.%以南方某水厂的中试和生产紫外消毒装置为基础,考察了紫外和化合氯联合消毒对生物活性炭出水细菌的杀灭效果,对紫外消毒在该水厂的应用效果进行了评价.研究表明,在480 J/m2的剂量下,生物活性炭出永细菌对数去除率可达2.6 lg,但是紫外无持续杀菌作用,水厂的紫外消毒装置总体效果良好,紫外化合氯消毒后出水细菌总数为0,紫外线消毒长时间运行后灭菌效率有所降低;生物活性炭工艺对氯胺消毒副产物有较好的控制效果,紫外消毒未增加氯消毒副产物的生成量.

  14. Iodine labelled diethylstilbestrol (DES) of high specific activity: A potential radiopharmaceutical for therapy of estrogen receptorpositive tumours and their metastases?

    International Nuclear Information System (INIS)

    After binding to the estrogen receptor (ER) estrogens are localized very close to the DNA. Therefore, radioactively labelled estrogens, especially in connection with Auger-electron emitters which have only a very short range (1-10 nm) of radiation, are excellent candidates to achieve high specific cytotoxicity, in combination with a low degree of side effects. Diethylstilbestrol (3,4-Di-(4'-hydroxyphenyl)-hexene-3) is a well-known, synthetic, non-steroidal estrogen, which has a higher affinity to the estrogen receptor than the natural hormone estradiol itself. The idea to use iodine labelled DES for imaging of ER positive tumours is not new. Several working groups successfully tried to label DES with different methods and investigated the diagnostic usefulness of the product. Most attempts for labelling with radioiodine have been made with a water soluble derivate of DES, the tetra-sodium salt of diethylstilbestrol-diphosphate (DES-2P). Former labelling methods had some disadvantages: low yield (20-30%), low specific activity (0.7 - 2.9 GBq/mmol), bad reproducibility, and time consuming procedures. Presumably, the low specific activity was the reason for the unsatisfying biodistribution data observed with this labelled compounds. In the present work a fast and simple labelling and purification method for *I-DES was used and its binding affinity for ER was determined. For testing its cytotoxic effects on MCF-7 mamma carcinoma cells different iodine isotopes bound to DES or in form of iodide were compared with regard to apoptosis, necrosis, and viability. Last but not least first animal experiments with tumour bearing mice were carried out. DES was iodinated by Chloramine T in methanolic solution. Purification and quality control was carried out with reversed phase HPLC (column: Column: Hypersil ODS, 250 x 4 mm, 10 Ym, Eluent A: Methanol G, Eluent B: Water G, Gradient: 20% A to 70% A within 5 min, Flow: 1 ml/min, UV-Detection: 254 nm). The dissociation constants for

  15. Comparison of [131I]-Tyr3-octreotate and [131I]DOTA-Tyr3-octreotate: the effect of DOTA on the pharmacokinetics and stability

    International Nuclear Information System (INIS)

    The introduction of radiolabeled somatostatin analogs for peptide receptor imaging and therapy of neuroendocrine cancer have become a primary focus of interest in nuclear medicine. In this work we studied the possibility of preparing radioiodinated octreotate derivatives, with high stability and favourable kinetic in vivo, because 131I-iodide is most frequently used in therapeutic nuclear medicine and aviable. We studied molar peptide to radionuclide ratio in order to obtain the mono-iodinated peptide (di-iodinated no longer binds to the somatostatin receptor). Like other radioiodinated proteins labeled on constituent tyrosine residues, it was important to study the possibility of dehalogenation in vivo. Despite DOTA chelating group was not necessary to the radioiodination procedure, we intended to evaluate the influence of the chelating group on the pharmacokinetic and the in vivo stability of the labeled peptide. 131I radiolabeling of Tyr3-octreotate and DOTA-Tyr3-octreotate was performed using Chloramine T method. A solution of 10 μg of peptide/40 μL of PBS (0.05M phosphate-buffered saline pH 7.5) was transferred to an Eppendorf cap. After addition of 10 μL (74 MBq) radioiodine and 5 μL of chloramine T solution (1mg/mL PBS), the cap was carefully stirred and the labeling reaction was allowed to proceed for 3 minutes at room temperature; 5 μL of sodium methabisulfite solution (2mg/mL PBS) was introduced as reducing agent. Radiochemical purity was determined by HPLC (Waters) using a RP C18 column (4.2 x 50 mm, 5 μm, Waters) with UV (230 nm) and radioactivity (Packard Canberra) detection, flow rate of 0.5 mL/minute with a linear gradient of 40-80% (v/v) methanol in 50 mM sodium acetate buffer (pH 5.5) for 20 minutes, maintained for another 25 minutes. Free radioiodine was also determined by horizontal zone electrophoresis (Amershan Pharmacia) on Whatman 1 paper, 0.05M barbital buffer, pH 8.6, 300V, 40 minutes. The stability of the compounds were evaluated

  16. Understanding, Monitoring, and Controlling Biofilm Growth in Drinking Water Distribution Systems.

    Science.gov (United States)

    Liu, Sanly; Gunawan, Cindy; Barraud, Nicolas; Rice, Scott A; Harry, Elizabeth J; Amal, Rose

    2016-09-01

    feasible with fluorescence microscopy (epifluorescence and CLSM imaging with DNA, RNA, EPS, and protein and lipid stains) and electron microscopy imaging (ESEM). Importantly, thorough identification of microbial fingerprints in drinking water biofilms is achievable with DNA sequencing techniques (the 16S rRNA gene-based identification), which have revealed a prevalence of previously undetected bacterial members. Technologies are now moving toward in situ monitoring of biomass growth in distribution networks, including the development of optical fibers capable of differentiating biomass from chemical deposits. Taken together, management of biofilm growth in water distribution systems requires an integrated approach, starting from the treatment of water prior to entering the networks to the potential implementation of "biofilm-limiting" operational conditions and, finally, ending with the careful selection of available technologies for biofilm monitoring and control. For the latter, conventional practices, including chlorine-chloramine disinfection, flushing of DWDS, nutrient removal, and emerging technologies are discussed with their associated challenges. PMID:27479445

  17. Utilization of N-X bonds in the synthesis of N-heterocycles.

    Science.gov (United States)

    Minakata, Satoshi

    2009-08-18

    Nitrogen-containing heterocycles--such as aziridines, pyrrolidines, piperidines, and oxazolines--frequently show up as substructures in natural products. In addition, some of these species show potent biological activities. Therefore, researchers would like to develop practical and convenient methods for constructing these heterocycles. Among the available methods, the transfer of N(1) units to organic molecules, especially olefins, is a versatile method for the synthesis of N-heterocycles. This Account reviews some of our recent work on the synthesis of N-heterocycles using the N-X bond. A nitrogen-halogen bond bearing an electron-withdrawing group on the nitrogen can be converted to a halonium ion. In the presence of C-C double bonds, these species produce three-membered cyclic halonium intermediates, which can be strong electrophiles and can produce stereocontrolled products. N-Halosuccinimides are representative sources of halonium ions, and the nitrogen of succinimide is rarely used in organic synthesis. If the nitrogen could act as a nucleophile, after releasing halonium ions to C-C double bonds, we expect great advances would be possible in the stereoselective functionalization of olefins. We chose N-chloro-N-sodio-p-toluenesulfonamide (chloramine-T, CT), an inexpensive and commercially available reagent, as our desired reactant. In the presence of a catalytic amount of CuCl or I(2) and AgNO(3), we achieved the direct aziridination of olefins with CT. The reaction catalyzed by I(2) could be carried out in water or silica-water as a green process. The reaction of iodoolefins with CT gave pyrrolidine derivatives under extremely mild conditions with complete stereoselectivity. We also extended the utility of the N-chloro-N-metallo reagent, which is often unstable and difficult to work with. Although CT does not react with electron-deficient olefins without a metal catalyst or an additive, we found that N-chloro-N-sodiocarbamates react with electron

  18. Analysis on Sanitary Quality of Hemodialysis Water in Hospitals of Hunan Province During the Period of 2009 - 2011%湖南省2009-2011年医院血液透析用水卫生质量分析

    Institute of Scientific and Technical Information of China (English)

    庞浩; 吴传业; 黄涛; 陈彦华; 胡冀; 杨新文

    2012-01-01

    目的 了解近3年湖南省医院血液透析用水的卫生状况,为血透用水卫生质量的规范化管理提供科学依据.方法 于2009-2011年先后采集湖南省的77家不同等级医院的血液透析用水样品,按照《血液透析用水卫生标准》进行理化指标、微生物指标的检测分析和判定.结果 血透用水中氯化物、钙、氯胺、内毒素和菌落总数等超标率分别为11.7%、2.6%、2.6%、23.4%、1.3%,其他项目均合格.三甲医院和非三甲医院透析用水合格率差异无统计学意义.结论 影响湖南省血液透析用水卫生质量的主要因素是氯化物和内毒素,定期监测、及时更换水处理设备组件、加强输配水管路的清洗消毒等措施是提高血液透析用水水质的关键.%Objective To investigate the sanitary quality of hemodialysis water among hospitals of Hunan Province in the past 3 years, and to provide a scientific basis for the standardized management of hemodialysis water. Methods The samples of hemodialysis water were collected from 77 different levels of hospitals in Hunan Province from 2009 to 2011. Physicochemical and microbial indexes of the samples were measured and judged according to Sanitary Standard for Hemodialysis Water. Results The disqualification rates of chloride, calcium, chloramine, esotoxin and total number of bacterial colony were 11. 7%, 2.6%,2.6%, 23.4%, and 1.3%, respectively. The other inspection items were qualified. But the qualified rates showed no statistically significant difference between 3A grade hospitals and other grades hospitals. Conclusions The main influencing factors for sanitary quality of hemodialysis water in Hunan are chloride and esotoxin. The key measures to improve the quality of hemodialysis water are to monitor regularly, replace water treatment device in time, wash and disinfect the water pipes.

  19. Mechanism and Influence Factors of Electrolytic Degradation of Urea by Low-amperage Electric Current%微电流电解对尿素降解的机理及影响因素研究

    Institute of Scientific and Technical Information of China (English)

    林莉; 谢雯静; 赵良元; 冯璁

    2015-01-01

    In this research,urea in swimming pools was treated by low-amperage electric current,and the influence factors including current density and chloride ion concentration and the mechanism of electrolytic removal of urea were investigated.Results indicated that urea was oxidized by active chlorine which was produced when there was high concentration of chloride ion in the solution with ruthenium-titanium as anode material and stainless steel as cathode material.No harmful by-product such as ammonia nitrogen or chloramines was produced.Urea possibly de-graded into gases like N2 and volatilized into the air.Current density and chloride ion concentration have great effect on the efficiency of urea removal.The removal of urea increased with the rise of current density and chloride ion concentration.Urea removal rate reached 99.5%at current density of 12 mA/cm2 and chloride ion concentra-tion of 400 mg/L by 30 min of electrolytic treatment.Due to the high removal rate of urea by electrolysis treatment with no need of electrolyte,electrolytic removal of urea by low-amperage electric current is feasible for the treatment of swimming pool water.%采用微电流电解技术对模拟游泳池水中的尿素进行降解处理,探索了电解对尿素的去除机理,研究了电流密度和氯离子浓度等因素对电解去除尿素效果的影响。结果表明:以钌钛和不锈钢分别做阳极和阴极材料,当水溶液中有较高浓度的氯离子存在时,电解过程中产生的活性氯使得尿素被氧化,尿素降解产物中无氨氮、氯胺等二次污染物,尿素极有可能通过电解生成了N2等气体挥发到空气中。电流密度和氯离子浓度对尿素的去除效率有很大影响,随着电流密度和氯离子浓度的增加,尿素去除效率逐渐上升。在500 mg/L的氯离子浓度条件下,电流密度为12 mA/cm2时,电解处理30 min时尿素去除率可达99.5%。将微电流电解技术应用于游泳池

  20. Comparative biodistribution profile of [131I]VIP and [131I]VIP10-28

    Directory of Open Access Journals (Sweden)

    Maria Tereza Colturato

    2005-10-01

    Full Text Available Various tumor cells express significantly higher amounts of VIP receptors (VIPR that provided the basis for the clinical use of radiolabeled VIP for the in vivo localization of tumors. This work studied the labeling of VIP and VIP10-28 with iodine-131 to compare the biological distribution of the labeled compounds in Nuce mice and the affinity for tumor cells. Both VIP and VIP10-28 peptides contain two tyrosine residues, in positions 10 and 22, that are theoretically equally susceptible to radioiodination employing oxidative electrophilic substitution using oxidizing agents like Chloramine T. Radiochemical purity of the reaction mixture was determined by electrophoresis and HPLC. The VIP peptide and the fragment were labeled with radioiodine with good radiochemical yield (above 96%. Suitable, but important differences can be observed in biological distribution studies. Comparatively, blood clearance was faster for labeled VIP and perhaps because of this, the uptake in tumor was lower, especially during the first hour. These differences observed in the biological distribution of the compounds can be related to the lipophilicity of the labeled compounds.Várias células tumorais expressam significantemente uma alta quantidade de receptores VIP (VIPR que determinam a base para o uso clínico de VIP radiomarcado para localização de tumores in vivo. Foi estudado neste trabalho a marcação do VIP e do fragmento VIP10-28 com iodo-131 comparando a distribuição biológica dos compostos marcados em camundongos Nude e sua afinidade pelas células tumorais. Ambos os peptídeos, VIP e VIP10-28. contém dois resíduos de tirosina nas posições 10 e 22, que teoricamente são igualmente susceptíveis pela substituição eletrofílica oxidativa do radioiodo utilizando Cloramina T como agente oxidante. A pureza radioquímica da mistura de reação foi determinada por eletroforese e cromatografia líquida de alta eficiência (CLAE. O VIP e fragmento foram

  1. Source Water Management for Disinfection By-Product Control using New York City's Operations Support Tool and On-Line Monitoring

    Science.gov (United States)

    Weiss, W. J.; Becker, W.; Schindler, S.

    2012-12-01

    The United States Environmental Protection Agency's 2006 Stage 2 Disinfectant / Disinfection Byproduct Rule (DBPR) for finished drinking waters is intended to reduce overall DBP levels by limiting the levels of total trihalomethanes (TTHM) and five of the haloacetic acids (HAA5). Under Stage 2, maximum contaminant levels (MCLs), 80 μg/L for TTHM and 60 μg/L for HAA5, are based on a locational running annual average for individual sites instead of as the system-wide quarterly running annual average of the Stage 1 DBPR. This means compliance will have to be met at sampling locations of peak TTHM and HAA5 concentrations rather than an average across the entire system. Compliance monitoring under the Stage 2 DBPR began on April 1, 2012. The New York City (NYC) Department of Environmental Protection (DEP) began evaluating potential impacts of the Stage 2 DBPR on NYC's unfiltered water supply in 2002 by monitoring TTHM and HAA5 levels at various locations throughout the distribution system. Initial monitoring indicated that HAA5 levels could be of concern in the future, with the potential to intermittently violate the Stage 2 DBPR at specific locations, particularly those with high water age. Because of the uncertainty regarding the long-term prospect for compliance, DEP evaluated alternatives to ensure compliance, including operational changes (reducing chlorine dose, changing flow configurations to minimize water age, altering pH, altering source water withdrawals); changing the residual disinfectant from free chlorine to chloramines; and engineered treatment alternatives. This paper will discuss the potential for using DEP's Operations Support Tool (OST) and enhanced reservoir monitoring to support optimization of source water withdrawals to minimize finished water DBP levels. The OST is a state-of-the-art decision support system (DSS) to provide computational and predictive support for water supply operations and planning. It incorporates a water supply system

  2. EDTA在后牙钙化闭塞根管预备中的应用研究%EDTA Application Research in the Calcified Block Root Canal Preparation of the Back Teeth

    Institute of Scientific and Technical Information of China (English)

    卢山; 黄昭毅; 郭宏剑

    2013-01-01

    Objective:The calcified block root canals have greatly influenced the curative effect to the root canals.To observe the EDTA paste in the application of calcified block root canal preparation,evaluate its clinical efficacy.Method:One hundred and twenty-four patients in our department from March 2009 to March 2012 were selected,140 back molar teeth,165 calcified block root canals and then divide them randomly into the group A and the group B,62 cases in each group.There were 62 cases,68 back molar teeth and 83 calcified block root canals in the group A.The group A was treated with the EDTA paste into root canal occlusion for root canal preparation,or temporary seal root canal EDTA root canal preparation a week later.There were 62 cases,72 back molar teeth and 82 calcified block root canals in the group B.The group B was treated with chloramine into the calcified block root canals and then had a root canal preparation.The preparatory effect of the root canals according to the X-ray and clinical examination were evaluated. Result:Eighty-three calcified block root canal in the group A with 72 root canal expansion,prepared well,the success rate was 86.75%.82 calcified block root canal in the group B only 18 root canal in root canal expansion,the success rate was 21.95%,and the breakage rate increased,the difference was statistically significant(P<0.01).Conclusion:The effect that EDTA paste has been used in the calcified block root canals is very good.It can raise remarkably the successful rate of root canal preparation.%目的:钙化闭塞根管严重影响根管治疗效果,通过观察EDTA糊剂在钙化闭塞根管预备中的应用,评价其临床疗效。方法:选取2009年3月-2012年3月本院牙体牙髓科就诊的124例患者,140颗后磨牙,165个钙化闭塞根管,所有的患者按照随机数字表法分为A组和B组各62例。A组62例68颗后磨牙83个钙化闭塞根管采用EDTA糊剂导入根管闭塞处进行根管预备,或根管

  3. SYSTEMATIC EVALUATION ON DISINFECTION EFFECICACY OF DIFFERENT CHLORINE DISINFECTANTS%不同种类含氯消毒剂消毒效果研究的系统评价

    Institute of Scientific and Technical Information of China (English)

    刘真; 张林; 熊鸿燕

    2011-01-01

    Disinfection; 37 English literatures are distributed in 17 journals, and 37.84% are published in Water Research, 13.51% are published in Journal of Hospital Infection.Chlorine, chlorine dioxide, sodium hypochlorite, sodium dichloroisocyanurate, trichloroisocyanuric acid ( TCCA), calcium hypochlorite and chloramine - T are involved in the 102 literatures.The order of comprehensive sterilization effect is as follows (from strong to weak): chlorine dioxide, TCCA, sodium dichloroisocyanurate, sodium hypochlorite.Coclusion Numbers of studies on bactericidal effect of chlorine disinfectants still leap into the front ranks among the studies of chemical disinfectant in the first decade of this century.Chlorine dioxide, sodium hypochlorite, sodium dichloroisocyanurate, and trichloroisocyanuric acid are the most widely used and studied.

  4. Understanding, Monitoring, and Controlling Biofilm Growth in Drinking Water Distribution Systems.

    Science.gov (United States)

    Liu, Sanly; Gunawan, Cindy; Barraud, Nicolas; Rice, Scott A; Harry, Elizabeth J; Amal, Rose

    2016-09-01

    feasible with fluorescence microscopy (epifluorescence and CLSM imaging with DNA, RNA, EPS, and protein and lipid stains) and electron microscopy imaging (ESEM). Importantly, thorough identification of microbial fingerprints in drinking water biofilms is achievable with DNA sequencing techniques (the 16S rRNA gene-based identification), which have revealed a prevalence of previously undetected bacterial members. Technologies are now moving toward in situ monitoring of biomass growth in distribution networks, including the development of optical fibers capable of differentiating biomass from chemical deposits. Taken together, management of biofilm growth in water distribution systems requires an integrated approach, starting from the treatment of water prior to entering the networks to the potential implementation of "biofilm-limiting" operational conditions and, finally, ending with the careful selection of available technologies for biofilm monitoring and control. For the latter, conventional practices, including chlorine-chloramine disinfection, flushing of DWDS, nutrient removal, and emerging technologies are discussed with their associated challenges.

  5. Labelling and biological valuation of anti-CD-20 for treatment of non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Full text: Anti-CD20 monoclonal chimeric humanized murine antibodies (Rituximab), have been successfully applied for the treatment of Non Hodgkin's Lymphoma. However, upon labelling of the mab-CD20 with β-emitters as 90Y, the therapeutic efficacy has significantly increased due to radiological effects of ionizing radiation. Our objective was to develop reliable and efficient methods for labelling anti-CD20 with β-emitters of therapeutic interest and simple and rugged quality control methods to evaluate radiochemical purity, biological performance and immunoreactivity assessment. 131I and 188Re have been used for the labelling of anti-CD20 as two attractive alternatives due to decay properties and availability (188Re: Eβmax: 2.2MeV, Eγ 0,155MeV, T=17h, generator produced; 131I: Eβmax: 0,63MeV, Eγ 0,364MeV, T=8d). Labelling of anti-CD20 was optimized following the oxidation procedure of chloramine-T in the case of 131I and the synthesis of 188Re(IV) complex with the previously reduced monoclonal antibody. Quality control of the species obtained were done by physicochemical methods, including ITLC-SG and HPLC, non specific protein precipitation, biological distribution in normal mice and immunoreactivity studies with membrane antigens extracted from isolated leucocytes. 131I- (more than 3.7 GBq/mL) was introduced on tyrosyl residues of the protein chain by adding 28 MBq to 20μg of anti CD20 (Mab Thera, 10mg/mL) at pH 7.4 and 1.3μg of Choramine-T. Purification was done by gel-permeation with sephadex G-25 (PD-10, Pharmacia). For labelling with 188Re, anti CD20 was first reduced by incubation with 2- mercaptoethanol and purified over a PD10 column. Fractions of reduced antibody were pooled and formulated as kit for instant labelling. Each kit contained 1mg anti-CD20; 82.8mg of sodium tartrate; 1.67 mg of stannous fluoride and 0.25 mg gentisic acid. For the labelling, sodium perrhenate (1.5-1.9 GBq) was acidified, added to the kit and then incubated for 1 hour at

  6. Study on biodistribution of 131 iodine labeled monoclonal antibody D-D3 against pro-gastrin-releasing peptide(31-98) in healthy Kunming mice%抗ProGRP(31-98)单克隆抗体D-D3的131I标记及其体内生物学分布研究

    Institute of Scientific and Technical Information of China (English)

    陈传新; 石怡珍; 杨仪; 唐军; 刘增礼; 徐巧玲

    2011-01-01

    Objective To study the 131I labeling methods, stability, and biological distribution pattern of D-D3 antibody against pro-gastrin-releasing peptide 31-98(ProGRP(31-98) ). Methods The radioiodination of D-D3 antibody was performed using the chloramine-T method. The radiochemical purity was determined through thin-layer chromotography. 131I-D-D3 was injected into the healthy Kunming mice via a tail vein, and the % ID/g for various organs was obtained, and then, the biodistribution and pharmacokinetics of 131 I-D-D3 antibody in healthy Kunming mice were studied. Results The 131 I-D-D3 labeling rate was (86.56 ± 3.8) %. The radiochemical purity of 131 I-D-D3 was (99.27 ± 0. 6)%. After 48 h incubating in 37 ℃ water bath, the radiochemical purity was (88.38 ± 0.4)%. While being mixed 24 h with healthy human serum, the radiochemical purity was still more than (64.43 ± 0.7)%. The metabolism of 131I-D-D3 in healthy Kunming mice was consistent with a two-compartment model with first-order absorption, T1/2α and T1/2β was 0.25,37.89 h, respectively. Conclusion The labeling efficiency and radiochemical purity of 131 I-D-D-D3 are high and stable. 131I-D-D3 is a promising radioimmunoimaging reagent for small cell lung cancer(SCLC).%目的 探讨抗胃泌素释放肽前体(ProGRP)(31-98)单克隆抗体D-D3的131I标记方法 及其在健康昆明小鼠体内的生物学分布规律与特点.方法 采用氯胺-T法用131I标记单克隆抗体D-D3,利用纸层析法测定其标记率、放化纯度和稳定性.取健康昆明小鼠50只,随机分为10组,每组5只,自昆明小鼠尾静脉注射131I-D-D3 1.48 kBq/100 μL(4 μCi/100 μL),各组小鼠分别于注射后5、15、30 min及1、2、4、8、12、24、48 h处死,取血液、心脏、肝脏、脾脏、肺脏、肾脏、胃、小肠、骨骼(右下肢)、肌肉(右下肢)和脑组织,称质量(g)后测放射性计数(cpm),计算各脏器组织的每克组织百分注射剂量率(%ID

  7. Effect of cardiac muscle collagen and actin on myocardiopathological change of diabetes mellitus%心肌胶原蛋白和肌动蛋白对糖尿病心肌病变的研究

    Institute of Scientific and Technical Information of China (English)

    吴伟; 张锦; 邱阳

    2005-01-01

    目的研究糖尿病大鼠不同病程心肌胶原蛋白和骨架蛋白含量的变化,阐明两者对糖尿病心肌病变发生的作用.方法制造糖尿病大鼠心肌模型随机分组.氯胺T法测定羟脯氨酸含量,代表心肌胶原总含量.心肌免疫组织化学染色测定心肌胶原蛋白(Collagen Ⅰ、Collagen Ⅲ)和心肌型α肌动蛋白(α-actin)及转化生长因子β1(TGF-β1)平均积分光密度(IOD).心肌病理改变的光镜和透射电镜观察.结果糖尿病痛程6个月组心肌胶原总含量明显高于病程3个月以内组(P<0.01).病程3个月之后Ⅰ型胶原蛋白表达伴随TGF-β1的表达开始较健康鼠明显增加(P<0.01).α-actin蛋白表达较健康鼠明显减少(P<O.01).糖尿病鼠心肌横切面可见粗大胶原纤维相互连接成网状,排列紊乱,分布不匀.心肌细胞心肌型α-actin蛋白分布不均匀,着色呈浅黄色,心肌纵切面可见α-actin蛋白表达主要分布于心肌肌膜处.病程3个月后大鼠心肌细胞核皱缩,线粒体肿胀、模糊,闰盘不连续,α-actin蛋白表达明显减少,有糖原沉积现象.结论Ⅰ型心肌胶原蛋白呈现持续性增加是糖尿病鼠心肌纤维化的主要原因.心肌细胞核皱缩,线粒体肿胀、模糊,闰盘不连续,糖原沉积和心肌型actin表达减少是糖尿病心肌病病理基础.%[Objective] To investigate the content changes of myocardial collagenprotein and actin at different stages of diabetes mellitus(DM) rats. So as to illustrate that they play a role in myocardial changes of DM. [Methods] Cardiac muscle model of DM rats was grouped randomly. The hydroxy proline contents were measured with the chloramine T method. The type Ⅰ collagen, type Ⅲ collagen,transforming factor beta1 (TGF-beta1) and cardiactype α-actin were determined by myocardial immunehistochemical stain. Myocardiopathological change were observed with light microscope and transmission electron microscope. [Results] The collagen contents

  8. Preclinical study of radioiodinated glucose-Tyr3-octreotate: Comparison with 111In-DOTA-Tyr3-octreotate

    International Nuclear Information System (INIS)

    Full text: Targeted radionuclide imaging and treatment are based upon the interaction of radioligands with receptors in the target tissue (namely high density receptor specific tumours). As receptors for somatostatin (mainly somatostatin receptor subtype-2 /sstr2/) are over-expressed in several human tumours of endocrine origin, a number of radiolabeled somatostatin analogs have been recently introduced as the vectors for targeted imaging and therapy; commercially available 111In-DTPA-octreotide being a gold standard in this field. Several publications demonstrate that a substitution of Tyr instead of Phe in the peptide position 3 and oxidation of carboxyl end of octreotide significantly increased the affinity of the peptide to sstr2. More recently it has been shown that NH2-terminal carbohydration leads to a further improvement of the peptide receptor affinity and its retention in the tumour. In this study we present preclinical analysis of distribution profile and elimination pathways of radioiodinated glucose-Tyr3-octreotate (125I-gluc-TOCA) in comparison with that of another promising targeted radiopharmaceutical, namely 111In-DOTA-Tyr3-octreotate (111In- DOTA-TOCA). Gluc-TOCA was radioiodinated using chloramine-T method. For radiolabeling of DOTA-TOCA with radiometal, to 200 μl of 0.4 M acetate buffer with 0.24 M gentisic acid pH 5, 10μl of peptide solution in 0.1% TFA (1mg/ml) were added together with 0.5-1 mCi of 111InCl3 in 0.04 M HCl. Reaction mixture was heated 25 minutes to 90-95 deg. C. Pharmacokinetic studies were performed on male Wistar rats. Results confirmed that specific internalization of 125I-gluc-TOCA by sstr2 - expressing AR423 rat pancreatic carcinoma cells in vitro was about twice of that for 111In-DOTA-TOCA. In rats, 125I-gluc-TOCA exhibited prolonged plasma clearance in comparison with the other peptide. Slower decrease of plasma radioactivity after 125I-gluc-TOCA was due to its higher lipophilicity and thus higher plasma protein binding

  9. Utilização do dióxido de cloro e do ácido peracético como substitutos do hipoclorito de sódio na sanitização do cheiro-verde minimamente processado Using chlorine dioxide and peracetic acid as substitutes for sodium hypocloride in the sanitization of minimally processed green seasoning

    Directory of Open Access Journals (Sweden)

    Silvana Mariana Srebernich

    2007-12-01

    propiciaram melhores resultados no controle microbiano. Entretanto, de acordo com os padrões existentes na legislação em vigor para Salmonella (ausência em 25 g de amostra e para E. coli (Minimally processed vegetables are ready to eat products that should be free of pathogenic microorganisms. These vegetables must be washed in good quality water, followed by the addition of a sanitizer to reduce the microbial count and minimize the product's deterioration, increasing its preservation and making it microbiologically safer. Sodium hypochlorite is the only sanitizer for this purpose allowed by Brazilian legislation. Although efficient, its use has been questioned because it is a precursor of organic chloramines, compounds of high carcinogenic potential. Many sanitizers have been proposed as substitutes of sodium hypochlorite in the disinfection of vegetables, including chlorine dioxide and peracetic acid. Therefore, based on microbial analyses, this research aimed to test the efficiency of chlorine dioxide (10, 25 and 50 ppm /2, 5 and 10 minutes and peracetic acid (60, 80 and 100 ppm/5, 10 and 15 minutes in comparison with sodium hypochlorite (120 ppm/15 minutes in the control of natural microbiota of minimally processed green seasoning. The green seasoning, which consists of fresh parsley and welsh onions, was washed in various concentrations of sanitizing solutions for given times and then processed to obtain sample of green seasoning. The control sample was washed only in tap water. The treatments were repeated on 3 distinct occasions at 4-month intervals, and 3 samples (packages of 150 g were collected from each treatment for microbial analysis of pathogenic Salmonella sp., total coliforms, Escherichia coli and total fungal count. The results of these analyses after statistical evaluation indicated that higher concentrations and longer sanitizing treatments led to better microbial control. However, according to the standards in the current legislation on Salmonella sp

  10. Risk assessment of Pseudomonas aeruginosa in water.

    Science.gov (United States)

    Mena, Kristina D; Gerba, Charles P

    2009-01-01

    . 1986). Outbreaks have also been reported from exposure to P. aeruginosa in swimming pools and water slides. Although P. aeruginosa has a reputation for being resistant to disinfection, most studies show that it does not exhibit any marked resistance to the disinfectants used to treat drinking water such as chlorine, chloramines, ozone, or iodine. One author, however, did find it to be slightly more resistant to UV disinfection than most other bacteria (Wolfe 1990). Although much has been written about biofilms in the drinking water industry, very little has been reported regarding the role of P. aeruginosa in biofilms. Tap water appears to be a significant route of transmission in hospitals, from colonization of plumbing fixtures. It is still not clear if the colonization results from the water in the distribution system, or personnel use within the hospital. Infections and colonization can be significantly reduced by placement of filters on the water taps. The oral dose of P. aeruginosa required to establish colonization in a healthy subject is high (George et al. 1989a). During dose-response studies, even when subjects (mice or humans) were colonized via ingestion, there was no evidence of disease. P. aeruginosa administered by the aerosol route at levels of 10(7) cells did cause disease symptoms in mice, and was lethal in aerosolized doses of 10(9) cells. Aerosol dose-response studies have not been undertaken with human subjects. Human health risks associated with exposure to P. aeruginosa via drinking water ingestion were estimated using a four-step risk assessment approach. The risk of colonization from ingesting P. aeruginosa in drinking water is low. The risk is slightly higher if the subject is taking an antibiotic resisted by P. aeruginosa. The fact that individuals on ampicillin are more susceptible to Pseudomonas gastrointestinal infection probably results from suppression of normal intestinal flora, which would allow Pseudomonas to colonize. The process of

  11. Effect of intestinal ischemia-reperfusion injury on the leptin levels in serum and adipose tissue%肠缺血再灌注损伤对血清及脂肪组织Leptin水平的影响

    Institute of Scientific and Technical Information of China (English)

    林季; 颜光涛; 王录焕; 郝秀华; 张凯; 薛辉

    2004-01-01

    BACKGROUND: Recent studies suggest that adipose tissue is not only the reservation of fat, but also a multi-potential endocrine organ secreting many functional cytokines. Leptin is a protein specifically secreted by adipose tissue, and primarily reduces food-intake and promotes energy expenditure.OBJECTIVE: To explore the effect of intestinal ischemia-reperfusion injury on leptin levels in serum and adipose tissue, and find out the role of leptin playing in acute inflammatory responses.DESIGN: A completely random self-and mutual-control experiment.SETTING and MATERIALS: The experiment was collected and completed in Research Laboratory of Biochemistry, General Hospital of Chinese PLA.Three male New Zealand white rabbits and fifty-four male Sprague-Dawley rats were used for experimental use.INTERVENTIONS: New Zealand white rabbits were immunized to obtain anti-leptin, leptin antigen was iodinated by chloramines-T method, thus we established a concise radioimmunoassay for murine leptin. An intestinal ischemia-reperfusion injury model of rats was established, and rats were divided randomly into six groups: sham-operation group(sham), 60-minute ischemia and 30-minute reperfusion group(I60-R30), I60-R90, I60-R150,I60-R240 and I60-R360; each group contained nine rats.MAIN OUTCOME MEASURES: The changes of leptin concentrations in serum and adipose tissue before and after ischemia-reperfusion injury were checked by the radioimmunoassay.RESULTS: Compared with self-control(before injury), serum leptin level of I60-R30 decreased significantly(t=2.3891, P<0.05), that of I60-R150 expressed a trend to increase and that of I60-R360 increased significantly ( t = - 2. 3437, P<0.05 ). Compared with sham after injury [ (9.88±1.87)μg/L], serum leptin level of I60-R240 expressed a trend to increase, that of I60-R360[ (19.43±2.84) μg/L] increased significantly( t = - 2. 8085, P <0.05) . Compared with sham after injury [ ( 11.12±1.27 ) ng], adipose leptin levels of I60-R30[ (4

  12. 益气养阴、活血化瘀中药对糖尿病大鼠脂代谢紊乱及蛋白质非酶糖基化的影响%Effect of Chinese herb for benefiting qi, nourishing yin, activating blood circulation and resolving stasis on lipid metabolic disturbance and protein nonenzyme glycosylation in diabetic rats

    Institute of Scientific and Technical Information of China (English)

    戴红

    2005-01-01

    administered once every day in above 6 groups,and the treating course was 8 weeks. ③ Before treatment, on the 3rd, 6th and 8th weeks after treatment, fasting blood sugar was tested with One Touch Ⅱ tester. 8 weeks later, automatic biochemistry analyzer was used to assay triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDLC) and high-density lipoprotein cholesterol (HDLC). Thoracic aorta was collected swiftly and chloramine-T method was used to assay hydroxyproline content in the extract from aorta. Hydroxyproline content ×7.14=collagen content. Fluorescence spectrometer was used to assay the fluorescence degree of AGEs in collagen extract. ④ t test was applied for difference comparison of measurement data.MAIN OUTCOME MEASURES: ① Comparison of fasting blood sugar before and after treatment in each group. ② Comparison of blood lipid,collagen content and fluorescence degree of collagen-protein AGEs in thoracic aorta in 8 weeks after treatment in each group.RESULTS: At the end of experiment, 8, 4, 2, 2 and 3 rats were died in model group, insulin group, HXY low, middle and high-dose groups respectively, due to which, 12, 8, 11, 13, 13 and 12 rats entered result analysis in various groups respectively. ① Fasting blood sugar: Before treatment, it was higher remarkably in model and various treating groups compared with normal control (P < 0.01) and 8 weeks after treatment, it was lower remarkably in insulin group and various HXY groups compared with model group and before treatment (P < 0.01). ② Levels of TC, TG, LDLC in serum: Those in insulin and model groups were higher remarkably than normal control (P < 0.05-0.01). Those in insulin group and various HXY groups were lower remarkably than normal group (P < 0.05-0.01). ③ Level of HDLC: It was lower remarkably in insulin group and model group compared with normal control (P < 0.05-0.01), it was higher remarkably in HXY low and middle-dose groups compared with model group (P