Science.gov

Sample records for accelerated hydrogen peroxide

  1. [Accelerated senescence of fresh-cut Chinese water chestnut tissues in relation to hydrogen peroxide accumulation].

    PubMed

    Peng, Li-Tao; Jiang, Yue-Ming; Yang, Shu-Zhen; Pan, Si-Yi

    2005-10-01

    Accelerated senescence of fresh-cut Chinese water chestnut (CWC) tissues in relation to active oxygen species (AOS) metabolism was investigated. Fresh-cut CWC (2 mm thick) and intact CWC were stored at 4 degrees C in trays wrapped with plastic films. Changes in superoxide anion production rate, activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were monitored, while contents of hydrogen peroxide, ascorbic acid, MDA as well as electrolyte leakage were measured. Fresh-cutting of CWC induced activities of SOD, CAT and APX to a certain extent (Fig. 2B and Fig. 3), but simultaneously stimulated superoxide anion production markedly (Fig. 2A), enhanced hydrogen peroxide accumulation and accelerated loss in ascorbic acid (Figs. 4 and 5), which resulted in increased lipid peroxidation indicated by malondialdehyde (MDA) content and electrolyte leakage (Fig. 1). Statistics analysis indicated that there was a significantly positive correlation among hydrogen peroxide accumulation, MDA content and electrolyte leakage (Table 1). Histochemical detection with 3, 3'-diaminobenzidine further demonstrated that hydrogen peroxide accumulation increased in fresh-cut CWC during storage (Fig. 5). AOS production rate and activities of SOD, CAT and APX changed little while no obvious hydrogen peroxide accumulation was observed, in intact CWC during storage.

  2. Hydrogen peroxide poisoning

    MedlinePlus

    ... peroxide is used in these products: Hydrogen peroxide Hair bleach Some contact lens cleaners Note: Household hydrogen peroxide ... it contains 97% water and 3% hydrogen peroxide. Hair bleaches are stronger. They usually have a concentration of ...

  3. Bioconversion of paper mill sludge to bioethanol in the presence of accelerants or hydrogen peroxide pretreatment.

    PubMed

    Gurram, Raghu Nandan; Al-Shannag, Mohammad; Lecher, Nicholas Joshua; Duncan, Shona M; Singsaas, Eric Lawrence; Alkasrawi, Malek

    2015-09-01

    In this study we investigated the technical feasibility of convert paper mill sludge into fuel ethanol. This involved the removal of mineral fillers by using either chemical pretreatment or mechanical fractionation to determine their effects on cellulose hydrolysis and fermentation to ethanol. In addition, we studied the effect of cationic polyelectrolyte (as accelerant) addition and hydrogen peroxide pretreatment on enzymatic hydrolysis and fermentation. We present results showing that removing the fillers content (ash and calcium carbonate) from the paper mill sludge increases the enzymatic hydrolysis performance dramatically with higher cellulose conversion at faster rates. The addition of accelerant and hydrogen peroxide pretreatment further improved the hydrolysis yields by 16% and 25% (g glucose / g cellulose), respectively with the de-ashed sludge. The fermentation process of produced sugars achieved up to 95% of the maximum theoretical ethanol yield and higher ethanol productivities within 9h of fermentation.

  4. Bioconversion of paper mill sludge to bioethanol in the presence of accelerants or hydrogen peroxide pretreatment.

    PubMed

    Gurram, Raghu Nandan; Al-Shannag, Mohammad; Lecher, Nicholas Joshua; Duncan, Shona M; Singsaas, Eric Lawrence; Alkasrawi, Malek

    2015-09-01

    In this study we investigated the technical feasibility of convert paper mill sludge into fuel ethanol. This involved the removal of mineral fillers by using either chemical pretreatment or mechanical fractionation to determine their effects on cellulose hydrolysis and fermentation to ethanol. In addition, we studied the effect of cationic polyelectrolyte (as accelerant) addition and hydrogen peroxide pretreatment on enzymatic hydrolysis and fermentation. We present results showing that removing the fillers content (ash and calcium carbonate) from the paper mill sludge increases the enzymatic hydrolysis performance dramatically with higher cellulose conversion at faster rates. The addition of accelerant and hydrogen peroxide pretreatment further improved the hydrolysis yields by 16% and 25% (g glucose / g cellulose), respectively with the de-ashed sludge. The fermentation process of produced sugars achieved up to 95% of the maximum theoretical ethanol yield and higher ethanol productivities within 9h of fermentation. PMID:26086086

  5. Macrophage Response to UHMWPE Submitted to Accelerated Ageing in Hydrogen Peroxide.

    PubMed

    Rocha, Magda F G; Mansur, Alexandra A P; Martins, Camila P S; Barbosa-Stancioli, Edel F; Mansur, Herman S

    2010-01-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been the most commonly used bearing material in total joint arthroplasty. Wear and oxidation fatigue resistance of UHMWPE are regarded as two important properties to extend the longevity of knee prostheses. The present study investigated the accelerated ageing of UHMWPE in hydrogen peroxide highly oxidative chemical environment. The sliced samples of UHMWPE were oxidized in a hydrogen peroxide solution for 120 days with their total level of oxidation (Iox) characterized by Fourier Transformed Infrared Spectroscopy (FTIR). The potential inflammatory response, cell viability and biocompatibility of such oxidized UHMWPE systems were assessed by a novel biological in vitro assay based on the secretion of nitric oxide (NO) by activated murine macrophages with gamma interferon (IFN-gamma) cytokine and lipopolysaccharide (LPS). Furthermore, macrophage morphologies in contact with UHMWPE oxidized surfaces were analyzed by cell spreading-adhesion procedure using scanning electron microscopy (SEM). The results have given significant evidence that the longer the period of accelerated aging of UHMWPE the higher was the macrophage inflammatory equivalent response based on NO secretion analysis.

  6. Concentration of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2006-01-01

    Methods for concentrating hydrogen peroxide solutions have been described. The methods utilize a polymeric membrane separating a hydrogen peroxide solution from a sweep gas or permeate. The membrane is selective to the permeability of water over the permeability of hydrogen peroxide, thereby facilitating the concentration of the hydrogen peroxide solution through the transport of water through the membrane to the permeate. By utilizing methods in accordance with the invention, hydrogen peroxide solutions of up to 85% by volume or higher may be generated at a point of use without storing substantial quantities of the highly concentrated solutions and without requiring temperatures that would produce explosive mixtures of hydrogen peroxide vapors.

  7. Hydrogen Peroxide Concentrator

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F.

    2007-01-01

    A relatively simple and economical process and apparatus for concentrating hydrogen peroxide from aqueous solution at the point of use have been invented. The heart of the apparatus is a vessel comprising an outer shell containing tubular membranes made of a polymer that is significantly more permeable by water than by hydrogen peroxide. The aqueous solution of hydrogen peroxide to be concentrated is fed through the interstitial spaces between the tubular membranes. An initially dry sweep gas is pumped through the interiors of the tubular membranes. Water diffuses through the membranes and is carried away as water vapor mixed into the sweep gas. Because of the removal of water, the hydrogen peroxide solution flowing from the vessel at the outlet end is more concentrated than that fed into the vessel at the inlet end. The sweep gas can be air, nitrogen, or any other gas that can be conveniently supplied in dry form and does not react chemically with hydrogen peroxide.

  8. Preparation of hydrogen peroxide

    SciTech Connect

    Brill, W.F.

    1984-07-31

    Hydrogen peroxide is produced in a reaction between carbon monoxide, oxygen, and water in the presence of a solvent using a Group 8 noble metal as a catalyst. Especially preferred as the working solution is palladium chloride in acetone.

  9. Hydrogen peroxide poisoning.

    PubMed

    Watt, Barbara E; Proudfoot, Alex T; Vale, J Allister

    2004-01-01

    Hydrogen peroxide is an oxidising agent that is used in a number of household products, including general-purpose disinfectants, chlorine-free bleaches, fabric stain removers, contact lens disinfectants and hair dyes, and it is a component of some tooth whitening products. In industry, the principal use of hydrogen peroxide is as a bleaching agent in the manufacture of paper and pulp. Hydrogen peroxide has been employed medicinally for wound irrigation and for the sterilisation of ophthalmic and endoscopic instruments. Hydrogen peroxide causes toxicity via three main mechanisms: corrosive damage, oxygen gas formation and lipid peroxidation. Concentrated hydrogen peroxide is caustic and exposure may result in local tissue damage. Ingestion of concentrated (>35%) hydrogen peroxide can also result in the generation of substantial volumes of oxygen. Where the amount of oxygen evolved exceeds its maximum solubility in blood, venous or arterial gas embolism may occur. The mechanism of CNS damage is thought to be arterial gas embolisation with subsequent brain infarction. Rapid generation of oxygen in closed body cavities can also cause mechanical distension and there is potential for the rupture of the hollow viscus secondary to oxygen liberation. In addition, intravascular foaming following absorption can seriously impede right ventricular output and produce complete loss of cardiac output. Hydrogen peroxide can also exert a direct cytotoxic effect via lipid peroxidation. Ingestion of hydrogen peroxide may cause irritation of the gastrointestinal tract with nausea, vomiting, haematemesis and foaming at the mouth; the foam may obstruct the respiratory tract or result in pulmonary aspiration. Painful gastric distension and belching may be caused by the liberation of large volumes of oxygen in the stomach. Blistering of the mucosae and oropharyngeal burns are common following ingestion of concentrated solutions, and laryngospasm and haemorrhagic gastritis have been

  10. Hydrogen peroxide catalytic decomposition

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2010-01-01

    Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated through the use of concentrated hydrogen peroxide fed as a monopropellant into a catalyzed thruster assembly. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50%-70% by volume, and may be increased in concentration in a continuous process preceding decomposition in the thruster assembly. The exhaust of the thruster assembly, rich in hydroxyl and/or hydroperoxy radicals, may be fed into a stream containing oxidizable components, such as nitric oxide, to facilitate their oxidation.

  11. Electrochemical Hydrogen Peroxide Generator

    NASA Technical Reports Server (NTRS)

    Tennakoon, Charles L. K.; Singh, Waheguru; Anderson, Kelvin C.

    2010-01-01

    Two-electron reduction of oxygen to produce hydrogen peroxide is a much researched topic. Most of the work has been done in the production of hydrogen peroxide in basic media, in order to address the needs of the pulp and paper industry. However, peroxides under alkaline conditions show poor stabilities and are not useful in disinfection applications. There is a need to design electrocatalysts that are stable and provide good current and energy efficiencies to produce hydrogen peroxide under acidic conditions. The innovation focuses on the in situ generation of hydrogen peroxide using an electrochemical cell having a gas diffusion electrode as the cathode (electrode connected to the negative pole of the power supply) and a platinized titanium anode. The cathode and anode compartments are separated by a readily available cation-exchange membrane (Nafion 117). The anode compartment is fed with deionized water. Generation of oxygen is the anode reaction. Protons from the anode compartment are transferred across the cation-exchange membrane to the cathode compartment by electrostatic attraction towards the negatively charged electrode. The cathode compartment is fed with oxygen. Here, hydrogen peroxide is generated by the reduction of oxygen. Water may also be generated in the cathode. A small amount of water is also transported across the membrane along with hydrated protons transported across the membrane. Generally, each proton is hydrated with 3-5 molecules. The process is unique because hydrogen peroxide is formed as a high-purity aqueous solution. Since there are no hazardous chemicals or liquids used in the process, the disinfection product can be applied directly to water, before entering a water filtration unit to disinfect the incoming water and to prevent the build up of heterotrophic bacteria, for example, in carbon based filters. The competitive advantages of this process are: 1. No consumable chemicals are needed in the process. The only raw materials

  12. Microcalorimetric Measurements of Hydrogen Peroxide Stability

    NASA Technical Reports Server (NTRS)

    Davis, Dennis D.; Hornung, Steven D.; Baker, Dave L.

    1999-01-01

    Recent interest in propellants with nontoxic reaction products has led to a resurgence of interest in hydrogen peroxide for various propellant applications. Because hydrogen peroxide is sensitive to contaminants and materials interactions, stability and shelf life are issues. A relatively new, ultrasensitive heat measurement technique, isothermal microcalorimetry, is being used at the White Sands Test Facility to monitor the decomposition of hydrogen peroxide at near ambient temperatures. Isothermal microcalorimetry measures the beat flow from a reaction vessel into a surrounding heat sink. In these applications, microcalorimetry is approximately 1,000 times more sensitive than accelerating rate calorimetry or differential scanning calorimetry for measuring thermal events. Experimental procedures have been developed for the microcalorimetric measurement of the ultra-small beat effects caused by incompatible interactions of hydrogen peroxide. The decomposition rates of hydrogen peroxide at the picomole/sec/gram level have been measured showing the effects of stabilizers and peroxide concentration. Typical measurements are carried out at 40 C over a 24-hour period, This paper describes a method for the conversion of the heat flow measurements to chemical reaction rates based on thermochemical considerations. The reaction rates are used in a study of the effects of stabilizer levels on the decomposition of propellant grade hydrogen peroxide.

  13. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No... distillation of the hydrogen peroxide formed; by decomposition of barium peroxide with sulfuric or...

  14. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No... distillation of the hydrogen peroxide formed; by decomposition of barium peroxide with sulfuric or...

  15. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No... distillation of the hydrogen peroxide formed; by decomposition of barium peroxide with sulfuric or...

  16. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogen peroxide. 184.1366 Section 184.1366 Food... Specific Substances Affirmed as GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No... distillation of the hydrogen peroxide formed; by decomposition of barium peroxide with sulfuric or...

  17. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogen peroxide. 184.1366 Section 184.1366 Food... GRAS § 184.1366 Hydrogen peroxide. (a) Hydrogen peroxide (H2O2, CAS Reg. No. 7722-84-1) is also... peroxide formed; by decomposition of barium peroxide with sulfuric or phosphoric acid; by...

  18. Stabilized aqueous hydrogen peroxide solution

    SciTech Connect

    Malin, M.J.; Sciafani, L.D.

    1988-05-17

    This patent describes a stabilized aqueous hydrogen peroxide solution having a pH below 7 and an amount of Ferric ion up to about 2 ppm comprising hydrogen peroxide, acetanilide having a concentration which ranges between 0.74 M Mol/L and 2.22 mMol/L, and o-benzene disulfonic acid or salt thereof at a concentration between about 0.86 mMol/L to about 1.62 mMol/L.

  19. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be... to exceed 0.001 percent by weight of the whey, providing that residual hydrogen peroxide is...

  20. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be... to exceed 0.001 percent by weight of the whey, providing that residual hydrogen peroxide is...

  1. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be... to exceed 0.001 percent by weight of the whey, providing that residual hydrogen peroxide is...

  2. Mechanism of toxicity of hydrogen peroxide

    SciTech Connect

    Imlay, J.A.

    1987-01-01

    We examined the capacity of hydrogen peroxide to injure E. coli. Externally applied hydrogen peroxide rapidly permeates the bacterial cell and causes at least two classes of potentially lethal damage. These classes were initially distinguished by the kinetics of their production. Additional distinctions have been made regarding the chemistry of cell injury and the details of the cell response. One class of cell damage consists of DNA lesions; if unrepaired, mode one killing results. Hydrogen peroxide does not directly attack the DNA. Instead, ferrous iron reduces the peroxide to generate a hydroxyl-radical-like species, which acts as a DNA oxidant. The peculiar kinetics of mode-one killing may reflect an high reaction rate between this radical and peroxide itself. Interestingly, NADH may chemically reduce ferric iron in order to start and maintain the sequence of redox reactions. The target of the other class of cell damage is unknown. This damage, unlike that associated with mode-one killing, does not rely upon Fenton chemistry. Scavenging enzymes, such as catalase and superoxide dismutase, contribute to resisting oxidative stress. Increases in catalase titer accelerate detoxification of peroxide and are responsible for the protective effects of oxyR induction. When oxidants elude this defense and nick DNA, a variety of enzymes-exonuclease III, endonuclease IV, and DNA polymerase I-repair the damage.

  3. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  4. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may be safely used to treat food in accordance with..., providing that residual hydrogen peroxide is removed by appropriate chemical or physical means during...

  5. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  6. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  7. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  8. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen peroxide... group. Eggs: Some strains of rainbow trout eggs are sensitive to hydrogen peroxide treatment at a...

  9. Progress toward hydrogen peroxide micropulsion

    SciTech Connect

    Whitehead, J C; Dittman, M D; Ledebuhr, A G

    1999-07-08

    A new self-pressurizing propulsion system has liquid thrusters and gas jet attitude control without heavy gas storage vessels. A pump boosts the pressure of a small fraction of the hydrogen peroxide, so that reacted propellant can controllably pressurize its own source tank. The warm decomposition gas also powers the pump and is supplied to the attitude control jets. The system has been incorporated into a prototype microsatellite for terrestrial maneuvering tests. Additional progress includes preliminary testing of a bipropellant thruster, and storage of unstabilized hydrogen peroxide in small sealed tanks.

  10. Materials Compatibility in High Test Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Gostowski, Rudy

    1999-01-01

    Previous ratings of the compatibility of high test hydrogen peroxide (HTP) with materials are not adequate for current needs. The goal of this work was to develop a new scheme of evaluation of compatibility of HTP with various materials. Procedures were developed to enrich commercially available hydrogen peroxide to 90% concentration and to assay the product. Reactivity testing, accelerated aging of materials and calorimetry studies were done on HTP with representative metallic and non-metallic materials. It was found that accelerated aging followed by concentration determination using refractive index effectively discriminated between different Class 2 metallic materials. Preliminary experiments using Differential Scanning Calorimetry (DSC) suggest that a calorimetry experiment is the most sensitive means to assay the compatibility of HTP with materials.

  11. Improved dual flow aluminum hydrogen peroxide battery

    NASA Astrophysics Data System (ADS)

    Marsh, Catherine; Licht, Stuart L.; Matthews, Donna

    1993-11-01

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  12. Improved dual flow aluminum hydrogen peroxide battery

    SciTech Connect

    Marsh, C.; Licht, S.L.; Matthews, D.

    1993-11-30

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  13. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  14. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  15. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  16. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  17. Sampling Stoichiometry: The Decomposition of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Clift, Philip A.

    1992-01-01

    Describes a demonstration of the decomposition of hydrogen peroxide to provide an interesting, quantitative illustration of the stoichiometric relationship between the decomposition of hydrogen peroxide and the formation of oxygen gas. This 10-minute demonstration uses ordinary hydrogen peroxide and yeast that can be purchased in a supermarket.…

  18. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  19. Improved Electrolytic Hydrogen Peroxide Generator

    NASA Technical Reports Server (NTRS)

    James, Patrick I.

    2005-01-01

    An improved apparatus for the electrolytic generation of hydrogen peroxide dissolved in water has been developed. The apparatus is a prototype of H2O2 generators for the safe and effective sterilization of water, sterilization of equipment in contact with water, and other applications in which there is need for hydrogen peroxide at low concentration as an oxidant. Potential applications for electrolytic H2O2 generators include purification of water for drinking and for use in industrial processes, sanitation for hospitals and biotechnological industries, inhibition and removal of biofouling in heat exchangers, cooling towers, filtration units, and the treatment of wastewater by use of advanced oxidation processes that are promoted by H2O2.

  20. NASA Hydrogen Peroxide Propulsion Perspective

    NASA Technical Reports Server (NTRS)

    Unger, Ronald; Lyles, Garry M. (Technical Monitor)

    2002-01-01

    This presentation is to provide the current status of NASA's efforts in the development of hydrogen peroxide in both mono-propellant and bi-propellant applications, consistent with the Space Launch Initiative goals of pursuing low toxicity and operationally simpler propellants for application in the architectures being considered for the 2nd Generation Reusable Launch Vehicle, also known as the Space Launch Initiative, or SLI.

  1. Coating for components requiring hydrogen peroxide compatibility

    NASA Technical Reports Server (NTRS)

    Yousefiani, Ali (Inventor)

    2010-01-01

    The present invention provides a heretofore-unknown use for zirconium nitride as a hydrogen peroxide compatible protective coating that was discovered to be useful to protect components that catalyze the decomposition of hydrogen peroxide or corrode when exposed to hydrogen peroxide. A zirconium nitride coating of the invention may be applied to a variety of substrates (e.g., metals) using art-recognized techniques, such as plasma vapor deposition. The present invention further provides components and articles of manufacture having hydrogen peroxide compatibility, particularly components for use in aerospace and industrial manufacturing applications. The zirconium nitride barrier coating of the invention provides protection from corrosion by reaction with hydrogen peroxide, as well as prevention of hydrogen peroxide decomposition.

  2. Hydrogen peroxide on the surface of Europa.

    PubMed

    Carlson, R W; Anderson, M S; Johnson, R E; Smythe, W D; Hendrix, A R; Barth, C A; Soderblom, L A; Hansen, G B; McCord, T B; Dalton, J B; Clark, R N; Shirley, J H; Ocampo, A C; Matson, D L

    1999-03-26

    Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis. PMID:10092224

  3. High Temperature Decomposition of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydropemxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  4. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2005-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  5. Hydrogen peroxide on the surface of Europa

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.; Anderson, M. S.; Johnson, R. E.; Smythe, W. D.; Hendrix, A. R.; Barth, C. A.; Soderblom, L. A.; Hansen, G. B.; McCord, T. B.; Dalton, J. B.; Clark, R. N.; Shirley, J. H.; Ocampo, A. C.; Matson, D. L.

    1999-01-01

    Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis.

  6. Hydrogen peroxide, from Wieland to Sies.

    PubMed

    Koppenol, Willem H

    2016-04-01

    A history of the formation of hydrogen peroxide in vivo is presented, starting with the discovery of catalase. The first hypothesis was formulated by Heinrich Wieland, who assumed that dioxygen reacted directly with organic molecules. This view was strongly criticised by Otto Warburg, Helmut Sies' academic grandfather. The involvement of hydrogen peroxide in physiological processes was investigated by Theodor Bücher, the "Doktorvater" of Helmut. Helmut's research made it possible to quantitate hydrogen peroxide in tissues.

  7. Hydrogen peroxide is a true first messenger.

    PubMed

    Holmquist, L; Stuchbury, G; Steele, M; Münch, G

    2007-01-01

    Hydrogen peroxide has been shown to act as a second messenger mediating intracellular redox-sensitive signal transduction. Here we show that hydrogen peroxide is also able to transmit pro-inflammatory signals from one cell to the other and that this action can be inhibited by extracellularly added catalase. If these data can be further substantiated, hydrogen peroxide might become as important as nitric oxide as a small molecule intercellular (first) messenger.

  8. Oxidative cleavage of cycloalkanones by hydrogen peroxide

    SciTech Connect

    Starostin, E.K.; Aleksandrov, A.V.; Nikishin, G.I.

    1986-07-10

    The authors have studied the reaction of cyclopentanone, cyclohexanone, cycloheptanone, and cyclododecanone with aqueous hydrogen peroxide over the temperature range 110-150/sup 0/C. The effects of temperature, hydrogen peroxide concentration, and the molar proportions of the reagents on the composition and yields of the products have been examined in the case of cyclohexanone. Oxidation of cyclohexanone by aqueous hydrogen peroxide at 110-150/sup 0/C gives 1,10-decanedicarboxylic acid and hexanoic acid as the principal products. Cyclopentanone and cycloheptanone react with hydrogen peroxide similarly to cyclohexanone, giving sebacic and pentanoic acids, and 1,12-dodecanedicarboxylic acids, respectively.

  9. Hydrogen peroxide enteritis: the "snow white" sign.

    PubMed

    Bilotta, J J; Waye, J D

    1989-01-01

    Hydrogen peroxide is a useful disinfectant that has achieved widespread utility in varied clinical settings. We report an epidemic of hydrogen peroxide enteritis that developed in seven patients in our gastrointestinal endoscopy unit during a 2-week period in early 1988. During endoscopy, using recently sterilized endoscopes that were flushed with 3% hydrogen peroxide after the glutaraldehyde cycle, instantaneous blanching (the "snow white" sign) and effervescence were noted on the mucosal surfaces when the water button was depressed. No patient subsequently suffered morbidity or mortality associated with this peroxide enteritis, and the biopsy specimens revealed nonspecific inflammation. The toxicity of hydrogen peroxide when used in enema form is reviewed, as well as the pathogenesis of peroxide enteritis.

  10. Molecular Association and Structure of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Giguere, Paul A.

    1983-01-01

    The statement is sometimes made in textbooks that liquid hydrogen peroxide is more strongly associated than water, evidenced by its higher boiling point and greater heat of vaporization. Discusses these and an additional factor (the nearly double molecular mass of the peroxide), focusing on hydrogen bonds and structure of the molecule. (JN)

  11. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  12. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  13. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  14. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  15. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  16. Fundamentals of ISCO Using Hydrogen Peroxide

    EPA Science Inventory

    Hydrogen peroxide is a common oxidant that has been applied extensively with in situ chemical oxidation (ISCO). Because of its widespread use in this and other fields, it has been extensively researched. This research has revealed that hydrogen peroxide has very complex chemistry...

  17. Vapor Hydrogen Peroxide Sterilization Certification

    NASA Astrophysics Data System (ADS)

    Chen, Fei; Chung, Shirley; Barengoltz, Jack

    For interplanetary missions landing on a planet of potential biological interest, United States NASA planetary protection currently requires that the flight system must be assembled, tested and ultimately launched with the intent of minimizing the bioload taken to and deposited on the planet. Currently the only NASA approved microbial reduction method is dry heat sterilization process. However, with utilization of such elements as highly sophisticated electronics and sensors in modern spacecraft, this process presents significant materials challenges and is thus an undesirable bioburden reduction method to design engineers. The objective of this work is to introduce vapor hydrogen peroxide (VHP) as an alternative to dry heat microbial reduction to meet planetary protection requirements. The VHP sterilization technology is widely used by the medical industry, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal of our study is determine the minimum VHP process conditions for PP acceptable microbial reduction levels. A series of experiments were conducted using Geobacillus stearothermophilus to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters -hydrogen peroxide concentration, number of pulses, and exposure duration -the investigation also considered the possible effect of environmental pa-rameters. Temperature, relative humidity, and material substrate effects on lethality were also studied. Based on the results, a most conservative D value was recommended. This recom-mended D value was also validated using VHP "hardy" strains that were isolated from clean-rooms and environmental populations collected from spacecraft relevant areas. The efficiency of VHP at ambient condition as well as VHP material compatibility will also be

  18. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  19. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2011-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  20. Membrane transport of hydrogen peroxide.

    PubMed

    Bienert, Gerd P; Schjoerring, Jan K; Jahn, Thomas P

    2006-08-01

    Hydrogen peroxide (H2O2) belongs to the reactive oxygen species (ROS), known as oxidants that can react with various cellular targets thereby causing cell damage or even cell death. On the other hand, recent work has demonstrated that H2O2 also functions as a signalling molecule controlling different essential processes in plants and mammals. Because of these opposing functions the cellular level of H2O2 is likely to be subjected to tight regulation via processes involved in production, distribution and removal. Substantial progress has been made exploring the formation and scavenging of H2O2, whereas little is known about how this signal molecule is transported from its site of origin to the place of action or detoxification. From work in yeast and bacteria it is clear that the diffusion of H2O2 across membranes is limited. We have now obtained direct evidence that selected aquaporin homologues from plants and mammals have the capacity to channel H2O2 across membranes. The main focus of this review is (i) to summarize the most recent evidence for a signalling role of H2O2 in various pathways in plants and mammals and (ii) to discuss the relevance of specific transport of H2O2.

  1. Hydrogen peroxide treatment of TCE contaminated soil

    SciTech Connect

    Hurst, D.H.; Robinson, K.G.; Siegrist, R.L.

    1993-12-31

    Solvent contaminated soils are ubiquitous in the industrial world and represent a significant environmental hazard due to their persistence and potentially negative impacts on human health and the environment. Environmental regulations favor treatment of soils with options which reduce the volume and toxicity of contaminants in place. One such treatment option is the in-situ application of hydrogen peroxide to soils contaminated with chlorinated solvents such as trichloroethylene (TCE). This study investigated hydrogen peroxide mass loading rates on removal of TCE from soils of varying organic matter content. Batch experiments conducted on contaminated loam samples using GC headspace analysis showed up to 80% TCE removal upon peroxide treatment. Column experiments conducted on sandy loam soils with high organic matter content showed only 25% TCE removal, even at hydrogen peroxide additions of 25 g peroxide per kg soil.

  2. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell

    PubMed Central

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D.

    2012-01-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells. PMID:23457415

  3. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell.

    PubMed

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D

    2012-11-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells.

  4. Ultrasonic degradation of Rhodamine B in the presence of hydrogen peroxide and some metal oxide.

    PubMed

    Mehrdad, Abbas; Hashemzadeh, Robab

    2010-01-01

    In this research, degradation of Rodamine B in the presence of (hydrogen peroxide), (hydrogen peroxide+ultrasound), (hydrogen peroxide+aluminum oxide), (hydrogen peroxide+aluminum oxide+ultrasound with different ultrasound power), (hydrogen peroxide+iron oxide) and (hydrogen peroxide+iron oxide+ultrasound with different ultrasound power) were investigated at 25 degrees C. The apparent rate constants for the examined systems were calculated by pseudo-first-order kinetics. The results indicate that the rate of degradation was accelerated by ultrasound. The rate of degradation was increased by increasing power ultrasound. The efficiency of the (hydrogen peroxide+iron oxide+ultrasound) system for degradation of Rodamine B was higher than the others examined.

  5. Isothermal Decomposition of Hydrogen Peroxide Dihydrate

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Baragiola, R. A.

    2011-01-01

    We present a new method of growing pure solid hydrogen peroxide in an ultra high vacuum environment and apply it to determine thermal stability of the dihydrate compound that forms when water and hydrogen peroxide are mixed at low temperatures. Using infrared spectroscopy and thermogravimetric analysis, we quantified the isothermal decomposition of the metastable dihydrate at 151.6 K. This decomposition occurs by fractional distillation through the preferential sublimation of water, which leads to the formation of pure hydrogen peroxide. The results imply that in an astronomical environment where condensed mixtures of H2O2 and H2O are shielded from radiolytic decomposition and warmed to temperatures where sublimation is significant, highly concentrated or even pure hydrogen peroxide may form.

  6. NASA Hydrogen Peroxide Propellant Hazards Technical Manual

    NASA Technical Reports Server (NTRS)

    Baker, David L.; Greene, Ben; Frazier, Wayne

    2005-01-01

    The Fire, Explosion, Compatibility and Safety Hazards of Hydrogen Peroxide NASA technical manual was developed at the NASA Johnson Space Center White Sands Test Facility. NASA Technical Memorandum TM-2004-213151 covers topics concerning high concentration hydrogen peroxide including fire and explosion hazards, material and fluid reactivity, materials selection information, personnel and environmental hazards, physical and chemical properties, analytical spectroscopy, specifications, analytical methods, and material compatibility data. A summary of hydrogen peroxide-related accidents, incidents, dose calls, mishaps and lessons learned is included. The manual draws from art extensive literature base and includes recent applicable regulatory compliance documentation. The manual may be obtained by United States government agencies from NASA Johnson Space Center and used as a reference source for hazards and safe handling of hydrogen peroxide.

  7. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  8. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in...)(1) of this section. (a) Identity. For the purpose of this section, hydrogen peroxide solution is...

  9. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, R.; Randhava, S.S.; Tsai, S.P.

    1997-09-02

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H{sub 2}O{sub 2} laden permeate. 1 fig.

  10. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, Rathin; Randhava, Sarabjit S.; Tsai, Shih-Perng

    1997-01-01

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H.sub.2 O.sub.2 laden permeate.

  11. Titanium corrosion in alkaline hydrogen peroxide environments

    NASA Astrophysics Data System (ADS)

    Been, Jantje

    1998-12-01

    The corrosion of Grade 2 titanium in alkaline hydrogen peroxide environments has been studied by weight loss corrosion tests, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) measurements and potentiodynamic polarography. Calcium ions and wood pulp were investigated as corrosion inhibitors. In alkaline peroxide, the titanium corrosion rate increased with increasing pH, temperature, and hydrogen peroxide concentration. The corrosion controlling mechanism is thought to be the reaction of the oxide with the perhydroxyl ion. No evidence of thermodynamically stable calcium titanate was found in the surface film of test coupons exposed to calcium-inhibited alkaline peroxide solutions. Calcium inhibition is probably the result of low local alkali and peroxide concentrations at the metal surface produced by reaction of adsorbed calcium with hydrogen peroxide. It has been shown that the inhibiting effect of calcium is temporary, possibly through an effect of calcium on the chemical and/or physical stability of the surface oxide. Pulp is an effective and stable corrosion inhibitor. Raising the pulp concentration decreased the corrosion rate. The inhibiting effect of pulp may be related to the adsorption and interaction of the pulp fibers with H 2O2, thereby decreasing the peroxide concentration and rendering the solution less corrosive. The presence of both pulp and calcium led to higher corrosion rates than obtained by either one inhibitor alone. Replacement of hydrofluoric acid with alkaline peroxide for pickling of titanium was investigated. Titanium corrosion rates in alkaline peroxide exceeded those obtained in the conventional hydrofluoric acid bath. General corrosion was observed with extensive roughening of the surface giving a dull gray appearance. Preferred dissolution of certain crystallographic planes was investigated through the corrosion of a titanium single crystal. Whereas the overall effect on the corrosion rate was small

  12. Catalyst Development for Hydrogen Peroxide Rocket Engines

    NASA Technical Reports Server (NTRS)

    Morlan, P. W.; Wu, P.-K.; Ruttle, D. W.; Fuller, R. P.; Nejad, A. S.; Anderson, W. E.

    1999-01-01

    The development of various catalysts of hydrogen peroxide was conducted for the applications of liquid rocket engines. The catalyst development includes silver screen technology, solid catalyst technology, and homogeneous catalyst technology. The silver screen technology development was performed with 85% (by weight) hydrogen peroxide. The results of this investigation were used as the basis for the catalyst design of a pressure-fed liquid-fueled upper stage engine. Both silver-plated nickel 200 screens and pure silver screens were used as the active metal catalyst during the investigation, The data indicate that a high decomposition efficiency (greater than 90%) of 85% hydrogen peroxide can be achieved at a bed loading of 0.5 lbm/sq in/sec with both pure silver and silver plated screens. Samarium oxide coating, however, was found to retard the decomposition process and the catalyst bed was flooded at lower bed loading. A throughput of 200 lbm of hydrogen peroxide (1000 second run time) was tested to evaluate the catalyst aging issue and performance degradation was observed starting at approximately 400 seconds. Catalyst beds of 3.5 inch in diameter was fabricated using the same configuration for a 1,000-lbf rocket engine. High decomposition efficiency was obtained with a low pressure drop across the bed. Solid catalyst using precious metal was also developed for the decomposition of hydrogen peroxide from 85% to 98% by weight. Preliminary results show that the catalyst has a strong reactivity even after 15 minutes of peroxide decomposition. The development effort also includes the homogeneous catalyst technology. Various non-toxic catalysts were evaluated with 98% peroxide and hydrocarbon fuels. The results of open cup drop tests indicate an ignition delay around 11 ms.

  13. Hydrogen Peroxide - Material Compatibility Studied by Microcalorimetry

    NASA Technical Reports Server (NTRS)

    Homung, Steven D.; Davis, Dennis D.; Baker, David; Popp, Christopher G.

    2003-01-01

    Environmental and toxicity concerns with current hypergolic propellants have led to a renewed interest in propellant grade hydrogen peroxide (HP) for propellant applications. Storability and stability has always been an issue with HP. Contamination or contact of HP with metallic surfaces may cause decomposition, which can result in the evolution of heat and gas leading to increased pressure or thermal hazards. The NASA Johnson Space Center White Sands Test Facility has developed a technique to monitor the decompositions of hydrogen peroxide at temperatures ranging from 25 to 60 C. Using isothermal microcalorimetry we have measured decomposition rates at the picomole/s/g level showing the catalytic effects of materials of construction. In this paper we will present the results of testing with Class 1 and 2 materials in 90 percent hydrogen peroxide.

  14. [Hydrogen peroxide inhibits acetylcholinesterase of myometrium sarcolemma].

    PubMed

    Danylovych, Iu V

    2009-01-01

    The action of hydrogen peroxide on acetylcholinesterase enzymatic activity in myometrium sarcolemma fraction is investigated. Hydrogen peroxide (0.1-26 microM), depending on the concentration, suppressed the activity. Acetylcholinesterase proved to be highly sensitive to the action of H2O2, making Ki = 2.4 +/- 0.4 microM, nH = 0.65 +/- 0.08 (n = 4-5). It is established, that hydrogen peroxide in the range of 1.6 - 6.4 microM essentially reduce V(0,max) and K(M). In the presence of dithiothreitole (a reducer of SH-groups of the membrane surface) the investigated substance effect considerably decreased.

  15. [Rasburicase therapy may cause hydrogen peroxide shock].

    PubMed

    Góth, László

    2008-08-24

    Hyperuricemia contributes to the pathomechanism of diseases such as renal failure, gout, tumor lysis syndrome and metabolic syndrome. Tumor lysis syndrome is a complication of malignancies caused by massive tumor cell lysis due to either spontaneous tumor cell lysis or to different therapies and it may cause hyperuricemia. Recently, for treatment of hyperuricemia the recombinant urate oxidase (rasburicase) therapy has been used. This enzyme converts uric acid with high affinity into soluble allantoin which is eliminated by the kidneys. In this reaction high concentration of hydrogen peroxide is generated. This hydrogen peroxide could cause hemolysis and especially methemoglobin formation, in case of glucose-6-phosphate-dehydrogenase and catalase deficiencies. Therefore it is recommended that these enzymes are determined before therapy. For monitoring of rasburicase therapy the determination of serum uric acid concentration is used. More than 95 per cent of Hungarian clinical laboratories are using the uricate oxidase/peroxidase reactions and hydrogen peroxide measurements in the uric acid assays. These assays may be interfered by ascorbic acid and hydrogen peroxide which is generated by rasburicase either in vivo or in vitro. PMID:18708312

  16. Recent Development in Hydrogen Peroxide Pumped Propulsion

    SciTech Connect

    Ledebuhr, A G; Antelman, D R; Dobie, D W; Gorman, T S; Jones, M S; Kordas, J F; McMahon, D H; Ng, L C; Nielsen, D P; Ormsby, A E; Pittenger, L C; Robinson, J A; Skulina, K M; Taylor, W G; Urone, D A; Wilson, B A

    2004-03-22

    This paper describes the development of a lightweight high performance pump-fed divert and attitude control system (DACS). Increased kinetic Kill Vehicles (KV) capabilities (higher .v and acceleration capability) will especially be needed for boost phase engagements where a lower mass KV DACS enables smaller overall interceptors. To increase KV performance while reducing the total DACS dry mass (<10 kg), requires a design approach that more closely emulates those found in large launch vehicles, where pump-fed propulsion enables high propellant-mass-fraction systems. Miniaturized reciprocating pumps, on a scale compatible with KV applications, offer the potential of a lightweight DACS with both high {Delta}v and acceleration capability, while still enabling the rapid pulsing of the divert thrusters needed in the end-game fly-in. Pumped propulsion uses lightweight low-pressure propellant tanks, as the main vehicle structure and eliminates the need for high-pressure gas bottles, reducing mass and increasing the relative propellant load. Prior work used hydrazine and demonstrated a propellant mass fraction >0.8 and a vehicle propulsion dry mass of {approx}3 kg. Our current approach uses the non-toxic propellants 90% hydrogen peroxide and kerosene. This approach enables faster development at lower costs due to the ease of handling. In operational systems these non-toxic propellants can simplify the logistics for manned environments including shipboard applications. This DACS design configuration is expected to achieve sufficient mass flows to support divert thrusters in the 1200 N to 1330 N (270 lbf to 300 lbf) range. The DACS design incorporates two pairs of reciprocating differential piston pumps (oxidizer and fuel), a warm-gas drive system, compatible bi-propellant thrusters, lightweight valves, and lightweight low-pressure propellant tanks. This paper summarizes the current development status and plans.

  17. Hydrogen peroxide fuels aging, inflammation, cancer metabolism and metastasis

    PubMed Central

    Martinez-Outschoorn, Ubaldo E; Lin, Zhao; Pavlides, Stephanos; Whitaker-Menezes, Diana; Pestell, Richard G; Howell, Anthony

    2011-01-01

    In 1889, Dr. Stephen Paget proposed the “seed and soil” hypothesis, which states that cancer cells (the seeds) need the proper microenvironment (the soil) for them to grow, spread and metastasize systemically. In this hypothesis, Dr. Paget rightfully recognized that the tumor microenvironment has an important role to play in cancer progression and metastasis. In this regard, a series of recent studies have elegantly shown that the production of hydrogen peroxide, by both cancer cells and cancer-associated fibroblasts, may provide the necessary “fertilizer,” by driving accelerated aging, DNA damage, inflammation and cancer metabolism, in the tumor microenvironment. By secreting hydrogen peroxide, cancer cells and fibroblasts are mimicking the behavior of immune cells (macrophages/neutrophils), driving local and systemic inflammation, via the innate immune response (NFκB). Thus, we should consider using various therapeutic strategies (such as catalase and/or other antioxidants) to neutralize the production of cancer-associated hydrogen peroxide, thereby preventing tumor-stroma co-evolution and metastasis. The implications of these findings for overcoming chemo-resistance in cancer cells are also discussed in the context of hydrogen peroxide production and cancer metabolism. PMID:21734470

  18. Systems and methods for generation of hydrogen peroxide vapor

    SciTech Connect

    Love, Adam H; Eckels, Joel Del; Vu, Alexander K; Alcaraz, Armando; Reynolds, John G

    2014-12-02

    A system according to one embodiment includes a moisture trap for drying air; at least one of a first container and a second container; and a mechanism for at least one of: bubbling dried air from the moisture trap through a hydrogen peroxide solution in the first container for producing a hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above a hydrogen peroxide solution in the second container for producing a hydrogen peroxide vapor. A method according one embodiment includes at least one of bubbling dried air through a hydrogen peroxide solution in a container for producing a first hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above the hydrogen peroxide solution in a container for producing a second hydrogen peroxide vapor. Additional systems and methods are also presented.

  19. An upper limit for stratospheric hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Traub, W. A.

    1984-01-01

    It has been postulated that hydrogen peroxide is important in stratospheric chemistry as a reservoir and sink for odd hydrogen species, and for its ability to interconvert them. The present investigation is concerned with an altitude dependent upper limit curve for stratospheric hydrogen peroxide, taking into account an altitude range from 21.5 to 38.0 km for January 23, 1983. The data employed are from balloon flight No. 1316-P, launched from the National Scientific Balloon Facility (NSBF) in Palestine, Texas. The obtained upper limit curve lies substantially below the data reported by Waters et al. (1981), even though the results are from the same latitude and are both wintertime measurements.

  20. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  1. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  2. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  3. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  4. Experimental investigation of hydrogen peroxide RF plasmas

    NASA Astrophysics Data System (ADS)

    Barni, R.; Decina, A.; Zanini, S.; D'Orazio, A.; Riccardi, C.

    2016-04-01

    This work reports a detailed experimental study of the plasma properties in low pressure RF discharges in hydrogen peroxide and a comparison with argon under the same operating conditions. H2O2 plasmas have been proposed for sterilization purposes. Electrical properties of the discharge were shown to be similar, as for the RF and DC voltages of the driving electrode. Bulk plasma volume remains stable, concentrated in an almost cylindrical region between the two facing electrodes. It was found that the electron temperature is almost uniform across the plasma and independent of the power level. This is higher than in argon discharges: T e  =  4.6  ±  0.9 eV versus T e  =  3.3  ±  1.1 eV. The plasma density increases almost linearly with the power level and a substantial negative ion component has been ruled out in hydrogen peroxide. Dissociation in the plasma gas phase was revealed by atomic hydrogen and hydroxyl radical emission in the discharge spectra. Emission from hydroxyl and atomic oxygen demonstrates that oxidizing radicals are produced by hydrogen peroxide discharges, revealing its usefulness for plasma processing other than sterilization, for instance to increase polymer film surface energy. On the other hand, argon could be considered as a candidate for the sterilization purposes due to the intense production of UV radiation.

  5. Asymmetric Epoxidation Using Hydrogen Peroxide as Oxidant.

    PubMed

    Wang, Chuan; Yamamoto, Hisashi

    2015-10-01

    Asymmetric epoxidation is one of the most important transformations in organic synthesis. Although tremendous progress was achieved in this field in the 1980s and 1990s, it is still desirable from both economical and ecological views to develop environmentally friendly catalytic epoxidation with a broad substrate scope. Hydrogen peroxide is a safe and cheap oxidant, which is easy to handle and generates water as the sole byproduct. Therefore, asymmetric epoxidation of olefins using hydrogen peroxide as oxidant has been a very active research field and has been investigated by many research groups in recent years. In this review, the exciting very recent developments of this rapidly growing area are surveyed and organized according to the catalyst systems.

  6. In vivo levels of mitochondrial hydrogen peroxide increase with age in mtDNA mutator mice.

    PubMed

    Logan, Angela; Shabalina, Irina G; Prime, Tracy A; Rogatti, Sebastian; Kalinovich, Anastasia V; Hartley, Richard C; Budd, Ralph C; Cannon, Barbara; Murphy, Michael P

    2014-08-01

    In mtDNA mutator mice, mtDNA mutations accumulate leading to a rapidly aging phenotype. However, there is little evidence of oxidative damage to tissues, and when analyzed ex vivo, no change in production of the reactive oxygen species (ROS) superoxide and hydrogen peroxide by mitochondria has been reported, undermining the mitochondrial oxidative damage theory of aging. Paradoxically, interventions that decrease mitochondrial ROS levels in vivo delay onset of aging. To reconcile these findings, we used the mitochondria-targeted mass spectrometry probe MitoB to measure hydrogen peroxide within mitochondria of living mice. Mitochondrial hydrogen peroxide was the same in young mutator and control mice, but as the mutator mice aged, hydrogen peroxide increased. This suggests that the prolonged presence of mtDNA mutations in vivo increases hydrogen peroxide that contributes to an accelerated aging phenotype, perhaps through the activation of pro-apoptotic and pro-inflammatory redox signaling pathways.

  7. Aluminium salts accelerate peroxidation of membrane lipids stimulated by iron salts.

    PubMed

    Gutteridge, J M; Quinlan, G J; Clark, I; Halliwell, B

    1985-07-31

    Aluminium salts do not themselves stimulate peroxidation of ox-brain phospholipid liposomes, but they greatly accelerate the peroxidation induced by iron(II) salts at acidic pH values. This effect of Al(III) is not seen at pH 7.4, perhaps because Al(III) salts form insoluble complexes at this pH in aqueous solution. Peroxidation of liposomes in the presence of Al(III) and Fe(II) salts is inhibited by the chelating agent desferrioxamine, and by EDTA and diethylenetriaminepentaacetic acid at concentrations greater than those of Fe(II) salt. Aluminium salts slightly stimulate the peroxidation of peroxide-depleted linolenic acid micelles, but they do not accelerate the peroxidation induced by addition of iron(II) salts to the micelles at acidic pH. Aluminium salts accelerate the peroxidation observed when human erythrocytes are treated with hydrogen peroxide at pH 7.4. Desferrioxamine decreases the peroxidation. We suggest that Al(III) ions produce an alteration in membrane structure that facilitates lipid peroxidation, and that the increased formation of fluorescent age pigments in the nervous system of patients exposed to toxic amounts of Al(III) may be related to this phenomenon. The ability of desferal to bind both iron (III) and aluminium(III) salts and to inhibit lipid peroxidation makes it an especially useful chelating agent in the treatment of 'aluminium overload'. PMID:2861853

  8. Vaporized hydrogen peroxide sterilization of freeze dryers.

    PubMed

    Johnson, J W; Arnold, J F; Nail, S L; Renzi, E

    1992-01-01

    The feasibility of using vapor hydrogen peroxide (VHP) as an alternative to steam sterilization has been examined using a pilot plant freeze dryer equipped with a prototype vapor generator. Specific objectives of the study discussed in this presentation were to: 1. Identify critical process variables affecting the lethality of VHP to Bacillus stearothermophilus spores, particularly within dead legs in the system. 2. Measure the efficacy of system degassing after sterilization. 3. Determine the effect of repeated sterilization cycles on the integrity of elastomeric components of the freeze dryer. Penetration of adequate concentrations of hydrogen peroxide vapor into small diameter piping, such as tubing connected to pressure gauges, is the most challenging aspect of VHP sterilization of freeze dryers. Prior to equipment modifications, spore strips placed within such dead legs remained positive irrespective of the number of gas/degas pulses and system pressure. Equipment modifications necessary to effect complete kill of biological indicators placed in system dead legs is discussed. Results of this study support the conclusion that vaporized hydrogen peroxide shows promise as an alternative sterilization method for freeze dryers. PMID:1474433

  9. PROCESS OF ELIMINATING HYDROGEN PEROXIDE IN SOLUTIONS CONTAINING PLUTONIUM VALUES

    DOEpatents

    Barrick, J.G.; Fries, B.A.

    1960-09-27

    A procedure is given for peroxide precipitation processes for separating and recovering plutonium values contained in an aqueous solution. When plutonium peroxide is precipitated from an aqueous solution, the supernatant contains appreciable quantities of plutonium and peroxide. It is desirable to process this solution further to recover plutonium contained therein, but the presence of the peroxide introduces difficulties; residual hydrogen peroxide contained in the supernatant solution is eliminated by adding a nitrite or a sulfite to this solution.

  10. Hazard Assessment of Personal Protective Clothing for Hydrogen Peroxide Service

    NASA Technical Reports Server (NTRS)

    Greene, Ben; McClure, Mark B.; Johnson, Harry T.

    2004-01-01

    Selection of personal protective equipment (PPE) for hydrogen peroxide service is an important part of the hazard assessment process. But because drip testing of chemical protective clothing for hydrogen peroxide service has not been reported for about 40 years, it is of great interest to test new protective clothing materials with new, high-concentration hydrogen peroxide following similar procedures. The suitability of PPE for hydrogen peroxide service is in part determined by observations made when hydrogen peroxide is dripped onto swatches of protective clothing material. Protective clothing material was tested as received, in soiled condition, and in grossly soiled condition. Materials were soiled by pretreating the material with potassium permanganate (KMnO4) solution then drying to promote a reaction. Materials were grossly soiled with solid KMnO4 to greatly promote reaction. Observations of results including visual changes to the hydrogen peroxide and materials, times to ignition, and self-extinguishing characteristics of the materials are reported.

  11. [Carbamide peroxide as source of hydrogen peroxide for the luminol application at crime scenes].

    PubMed

    Schwarz, Lothar; Hermanowski, Mona-Lena

    2009-01-01

    The solution of hydrogen peroxide is a critical ingredient of the Weber luminol application for blood detection at the crime scene. An ideal alternative to the unstable hydrogen peroxide is a solid compound which is easy to transport, stable and quick to solve in water at the crime scene. Carbamide peroxide (urea peroxide) is one of these solid hydrogen peroxide carriers which is easy to obtain as one gram tablets. At dry conditions it is stable over a long period at room temperature and even for a short time at higher temperatures. But at 70 degrees C (180 degrees F) the tablets go out of shape and cake after one hour. In the application of luminol there are no differences between the use of hydrogen peroxide and carbamide peroxide.

  12. Preliminary study of a hydrogen peroxide rocket for use in moving source jet noise tests

    NASA Technical Reports Server (NTRS)

    Plencner, R. M.

    1977-01-01

    A preliminary investigation was made of using a hydrogen peroxide rocket to obtain pure moving source jet noise data. The thermodynamic cycle of the rocket was analyzed. It was found that the thermodynamic exhaust properties of the rocket could be made to match those of typical advanced commercial supersonic transport engines. The rocket thruster was then considered in combination with a streamlined ground car for moving source jet noise experiments. When a nonthrottlable hydrogen peroxide rocket was used to accelerate the vehicle, propellant masses and/or acceleration distances became too large. However, when a throttlable rocket or an auxiliary system was used to accelerate the vehicle, reasonable propellant masses could be obtained.

  13. A Modified Demonstration of the Catalytic Decomposition of Hydrogen Peroxide

    NASA Astrophysics Data System (ADS)

    Trujillo, Carlos Alexander

    2005-06-01

    A safer and cheaper version of the popular catalyzed decomposition of hydrogen peroxide demonstration commonly called the “Elephants’ Toothpaste” is presented. Hydrogen peroxide is decomposed in the presence of a surfactant by the enzyme catalase producing foam. Catalase has a higher activity compared with the traditional iodide and permits the use of diluted hydrogen peroxide solutions. The demonstration can be made with household products with similar amazing effects.

  14. Amperometric sensing of hydrogen peroxide vapor for security screening.

    PubMed

    Benedet, John; Lu, Donglai; Cizek, Karel; La Belle, Jeff; Wang, Joseph

    2009-09-01

    Rapid detection of the hydrogen peroxide precursor of peroxide explosives is required in numerous security screening applications. We describe a highly sensitive and selective amperometric detection of hydrogen peroxide vapor at an agarose-coated Prussian-blue (PB) modified thick-film carbon transducer. The sensor responds rapidly and reversibly to dynamic changes in the level of the peroxide vapor, with no apparent carry over and with a detection limit of 6 ppbv. The remarkable selectivity of the PB-based screen-printed electrode towards hydrogen peroxide leads to effective discrimination against common beverage samples. For example, blind tests have demonstrated the ability to selectively and non-invasively identify concealed hydrogen peroxide in drinking cups and bottles. The attractive performance of the new microfabricated PB-based amperometric peroxide vapor sensor indicates great potential for addressing a wide range of security screening and surveillance applications.

  15. Use of Hydrogen Peroxide to Disinfect Hydroponic Plant Growth Systems

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Henderson, Keith

    2000-01-01

    Hydrogen peroxide was studied as an alternative to conventional bleach and rinsing methods to disinfect hydroponic plant growth systems. A concentration of 0.5% hydrogen peroxide was found to be effective. Residual hydrogen peroxide can be removed from the system by repeated rinsing or by flowing the solution through a platinum on aluminum catalyst. Microbial populations were reduced to near zero immediately after treatment but returned to pre-disinfection levels 2 days after treatment. Treating nutrient solution with hydrogen peroxide and planting directly into trays being watered with the nutrient solution without replenishment, was found to be detrimental to lettuce germination and growth.

  16. Monolithic Hydrogen Peroxide Catalyst Bed Development

    NASA Technical Reports Server (NTRS)

    Ponzo, J. B.

    2003-01-01

    With recent increased industry and government interest in rocket grade hydrogen peroxide as a viable propellant, significant effort has been expended to improve on earlier developments. This effort has been predominately centered in improving heterogeneous. typically catalyst beds; and homogeneous catalysts, which are typically solutions of catalytic substances. Heterogeneous catalyst beds have traditionally consisted of compressed wire screens plated with a catalytic substance, usually silver, and were used m many RCS applications (X-1, Mercury, and Centaur for example). Aerojet has devised a heterogeneous catalyst design that is monolithic (single piece), extremely compact, and has pressure drops equal to or less than traditional screen beds. The design consists of a bonded stack of very thin, photoetched metal plates, silver coated. This design leads to a high surface area per unit volume and precise flow area, resulting in high, stable, and repeatable performance. Very high throughputs have been demonstrated with 90% hydrogen peroxide. (0.60 lbm/s/sq in at 1775-175 psia) with no flooding of the catalyst bed. Bed life of over 900 seconds has also been demonstrated at throughputs of 0.60 lbm/s/sq in across varying chamber pressures. The monolithic design also exhibits good starting performance, short break-in periods, and will easily scale to various sizes.

  17. PROPULSE 980: A Hydrogen Peroxide Enrichment System

    NASA Technical Reports Server (NTRS)

    Boxwell, Robert; Bromley, G.; Wanger, Robert; Pauls, Dan; Maynard, Bryon; McNeal, Curtis; Dumbacher, D. L. (Technical Monitor)

    2000-01-01

    The PROPULSE 980 unit is a transportable processing plant that enriches aerospace grade hydrogen peroxide from 90% to 98% final concentration. The unit was developed by Degussa-H Is, in cooperation with Orbital, NASA Marshall Space Center, and NASA Stennis Space Center. The system is a self-contained unit that houses all of the process equipment, instrumentation and controls to perform the concentration operation nearly autonomously. It is designed to produce non-bulk quantities of 98% hydrogen peroxide. The enrichment unit design also maintains system, personnel and environmental safety during all aspects of the enrichment process and final product storage. As part of the Propulse 980 checkout and final buyoff, it will be disassembled at the Degussa-H Is Corporation plant in Theodore, AL, transported to the Stennis Space Center, reassembled and subjected to a series of checkout tests to verify design objectives have been met. This paper will summarize the basic project elements and provide an update on the present status of the project.

  18. Simple, field portable colorimetric detection device for organic peroxides and hydrogen peroxide

    SciTech Connect

    Pagoria, Philip F.; Mitchell, Alexander R.; Whipple, Richard E.; Carman, M. Leslie; Reynolds, John G.; Nunes, Peter; Shields, Sharon J.

    2010-11-09

    A simple and effective system for the colorimetric determination of organic peroxides and hydrogen peroxide. A peroxide pen utilizing a swipe material attached to a polyethylene tube contains two crushable vials. The two crushable vials contain a colorimetric reagent separated into dry ingredients and liquid ingredients. After swiping a suspected substance or surface the vials are broken, the reagent is mixed thoroughly and the reagent is allowed to wick into the swipe material. The presence of organic peroxides or hydrogen peroxide is confirmed by a deep blue color.

  19. Demonstration of the Catalytic Decomposition of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Conklin, Alfred R. Jr.; Kessinger, Angela

    1996-01-01

    Describes a demonstration known as Elephant's Toothpaste in which the decomposition of hydrogen peroxide is catalyzed by iodide. Oxygen is released and soap bubbles are produced. The foam produced is measured, and results show a good relationship between the amount of foam and the concentration of the hydrogen peroxide. (DDR)

  20. Measurement of hydrogen peroxide from aircraft

    SciTech Connect

    Kok, G.L.

    1980-01-01

    Hydrogen peroxide (H/sub 2/O/sub 2/) is an important species in both the homogeneous and the heterogeneous chemistry of the troposphere. Measurement of H/sub 2/O/sub 2/ from aircraft provides information on the distribution of H/sub 2/O/sub 2/ in the troposphere and provides a great deal of additional information which cannot be obtained from ground-based measurements. Three analytical techniques for atmospheric H/sub 2/O/sub 2/ are available. Two of these are colorimetric methods involving the formation of a colored complex with titanium salt. In 1978, a chemiluminescent method for the determination of atmospheric H/sub 2/O/sub 2/ was introduced. This method involves the reaction of H/sub 2/O/sub 2/ with luminol in the presence of a copper catalyst, with the chemiluminescence serving as the basis of the analytical reaction.

  1. Locating bomb factories by detecting hydrogen peroxide.

    PubMed

    Romolo, Francesco Saverio; Connell, Samantha; Ferrari, Carlotta; Suarez, Guillaume; Sauvain, Jean-Jacques; Hopf, Nancy B

    2016-11-01

    The analytical capability to detect hydrogen peroxide vapour can play a key role in localizing a site where a H2O2 based Improvised Explosive (IE) is manufactured. In security activities it is very important to obtain information in a short time. For this reason, an analytical method to be used in security activity needs portable devices. The authors have developed the first analytical method based on a portable luminometer, specifically designed and validated to locate IE manufacturing sites using quantitative on-site vapour analysis for H2O2. The method was tested both indoor and outdoor. The results demonstrate that the detection of H2O2 vapours could allow police forces to locate the site, while terrorists are preparing an attack. The collected data are also very important in developing new sensors, able to give an early alarm if located at a proper distance from a site where an H2O2 based IE is prepared.

  2. Hydrogen Peroxide Storage in Small Sealed Tanks

    SciTech Connect

    Whitehead, J.

    1999-10-20

    Unstabilized hydrogen peroxide of 85% concentration has been prepared in laboratory quantities for testing material compatibility and long term storage on a small scale. Vessels made of candidate tank and liner materials ranged in volume from 1 cc to 2540 cc. Numerous metals and plastics were tried at the smallest scales, while promising ones were used to fabricate larger vessels and liners. An aluminum alloy (6061-T6) performed poorly, including increasing homogeneous decay due to alloying elements entering solution. The decay rate in this high strength aluminum was greatly reduced by anodizing. Better results were obtained with polymers, particularly polyvinylidene fluoride. Data reported herein include ullage pressures as a function of time with changing decay rates, and contamination analysis results.

  3. Bactericidal effect of hydrogen peroxide on spacecraft isolates

    NASA Technical Reports Server (NTRS)

    Wardle, M. D.; Renninger, G. M.

    1975-01-01

    Results are presented for an experimental study designed to assess the effect of hydrogen peroxide on both sporeforming and nonsporeforming spacecraft isolates as an initial step in determining its suitability for microbiological decontamination of certain United States spacecraft. Survivor data were obtained for eight bacterial isolates (six sporeformers and two nonsporeformers) recovered before launch Mariner 9 and exposed to concentrations of 3, 10, and 15% hydrogen peroxide. The effects of various concentrations of hydrogen peroxide on the spores are presented in tabular form, along with the percentage of survival of nonsporeformers exposed to hydrogen peroxide. No viable vegetative cells were recovered after a 10-min exposure time to any of the three concentration of hydrogen peroxide.

  4. Kohlrabi-based amperometric biosensor for hydrogen peroxide measurement

    SciTech Connect

    Lu Chen; Meng Shan Lin; Hara, Minoru; Rechnitz, G.A. )

    1991-01-01

    Hydrogen peroxide is a very important substance both in biological and environmental reactions. Hydrogen peroxide was determined amperometrically in a steady-state arrangement by utilizing a kohlrabi-ferrocene based carbon paste electrode. A very short response time (2.6 seconds) and a relatively large usable pH range (5.0-7.4) were obtained. Several important hydrogen donors were studied as possible interferences.

  5. Kinetics of Platinum-Catalyzed Decomposition of Hydrogen Peroxide

    NASA Astrophysics Data System (ADS)

    Vetter, Tiffany A.; Colombo, D. Philip, Jr.

    2003-07-01

    CIBA Vision Corporation markets a contact lens cleaning system that consists of an AOSEPT disinfectant solution and an AOSEPT lens cup. The disinfectant is a buffered 3.0% m/v hydrogen peroxide solution and the cup includes a platinum-coated AOSEPT disc. The hydrogen peroxide disinfects by killing bacteria, fungi, and viruses found on the contact lenses. Because the concentration of hydrogen peroxide needed to disinfect is irritating to eyes, the hydrogen peroxide needs to be neutralized, or decomposed, before the contact lenses can be used again. A general chemistry experiment is described where the kinetics of the catalyzed decomposition of the hydrogen peroxide are studied by measuring the amount of oxygen generated as a function of time. The order of the reaction with respect to the hydrogen peroxide, the rate constant, and the energy of activation are determined. The integrated rate law is used to determine the time required to decompose the hydrogen peroxide to a concentration that is safe for eyes.

  6. Hydrogen peroxide mechanosynthesis in siloxane-hydrogel contact lenses.

    PubMed

    Tavazzi, Silvia; Ferraro, Lorenzo; Cozza, Federica; Pastori, Valentina; Lecchi, Marzia; Farris, Stefano; Borghesi, Alessandro

    2014-11-26

    Drug-loaded contact lenses are emerging as the preferred treatment method for several ocular diseases, and efforts are being directed to promote extended and controlled delivery. One strategy is based on delivery induced by environmental triggers. One of these triggers can be hydrogen peroxide, since many platforms based on drug-loaded nanoparticles were demonstrated to be hydrogen-peroxide responsive. This is particularly interesting when hydrogen peroxide is the result of a specific pathophysiological condition. Otherwise, an alternative route to induce drug delivery is here proposed, namely the mechano-synthesis. The present work represents the proof-of-concept of the mechanosynthesis of hydrogen peroxide in siloxane-hydrogel contact lenses as a consequence of the cleavage of siloxane bonds at the interface between the polymer and water in aqueous phase. Their spongy morphology makes contact lenses promising systems for mechanical-to-chemical energy conversion, since the amount of hydrogen peroxide is expected to scale with the interfacial area between the polymer and water. The eyelid pressure during wear is sufficient to induce the hydrogen peroxide synthesis with concentrations which are biocompatible and suitable to trigger the drug release through hydrogen-peroxide-responsive platforms. For possible delivery on demand, the integration of piezoelectric polymers in the siloxane-hydrogel contact lenses could be designed, whose mechanical deformation could be induced by an applied wireless-controlled voltage.

  7. Locating bomb factories by detecting hydrogen peroxide.

    PubMed

    Romolo, Francesco Saverio; Connell, Samantha; Ferrari, Carlotta; Suarez, Guillaume; Sauvain, Jean-Jacques; Hopf, Nancy B

    2016-11-01

    The analytical capability to detect hydrogen peroxide vapour can play a key role in localizing a site where a H2O2 based Improvised Explosive (IE) is manufactured. In security activities it is very important to obtain information in a short time. For this reason, an analytical method to be used in security activity needs portable devices. The authors have developed the first analytical method based on a portable luminometer, specifically designed and validated to locate IE manufacturing sites using quantitative on-site vapour analysis for H2O2. The method was tested both indoor and outdoor. The results demonstrate that the detection of H2O2 vapours could allow police forces to locate the site, while terrorists are preparing an attack. The collected data are also very important in developing new sensors, able to give an early alarm if located at a proper distance from a site where an H2O2 based IE is prepared. PMID:27591582

  8. Molecular evolution of hydrogen peroxide degrading enzymes.

    PubMed

    Zámocký, Marcel; Gasselhuber, Bernhard; Furtmüller, Paul G; Obinger, Christian

    2012-09-15

    For efficient removal of intra- and/or extracellular hydrogen peroxide by dismutation to harmless dioxygen and water (2H(2)O(2) → O(2) + 2H(2)O), nature designed three metalloenzyme families that differ in oligomeric organization, monomer architecture as well as active site geometry and catalytic residues. Here we report on the updated reconstruction of the molecular phylogeny of these three gene families. Ubiquitous typical (monofunctional) heme catalases are found in all domains of life showing a high structural conservation. Their evolution was directed from large subunit towards small subunit proteins and further to fused proteins where the catalase fold was retained but lost its original functionality. Bifunctional catalase-peroxidases were at the origin of one of the two main heme peroxidase superfamilies (i.e. peroxidase-catalase superfamily) and constitute a protein family predominantly present among eubacteria and archaea, but two evolutionary branches are also found in the eukaryotic world. Non-heme manganese catalases are a relatively small protein family with very old roots only present among bacteria and archaea. Phylogenetic analyses of the three protein families reveal features typical (i) for the evolution of whole genomes as well as (ii) for specific evolutionary events including horizontal gene transfer, paralog formation and gene fusion. As catalases have reached a striking diversity among prokaryotic and eukaryotic pathogens, understanding their phylogenetic and molecular relationship and function will contribute to drug design for prevention of diseases of humans, animals and plants. PMID:22330759

  9. Hydrogen peroxide diffusion dynamics in dental tissues.

    PubMed

    Ubaldini, A L M; Baesso, M L; Medina Neto, A; Sato, F; Bento, A C; Pascotto, R C

    2013-07-01

    The aim of this study was to investigate the diffusion dynamics of 25% hydrogen peroxide (H2O2) through enamel-dentin layers and to correlate it with dentin's structural alterations. Micro-Raman Spectroscopy (MRS) and Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) were used to measure the spectra of specimens before and during the bleaching procedure. H2O2 was applied to the outer surface of human enamel specimens for 60 minutes. MRS measurements were performed on the inner surface of enamel or on the subsurface dentin. In addition, H2O2 diffusion dynamics from outer enamel to dentin, passing through the dentin-enamel junction (DEJ) was obtained with Raman transverse scans. FTIR-PAS spectra were collected on the outer dentin. MRS findings revealed that H2O2 (O-O stretching µ-Raman band) crossed enamel, had a more marked concentration at DEJ, and accumulated in dentin. FTIR-PAS analysis showed that H2O2 modified dentin's organic compounds, observed by the decrease in amides I, II, and III absorption band intensities. In conclusion, H2O2 penetration was demonstrated to be not merely a physical passage through enamel interprismatic spaces into the dentinal tubules. H2O2 diffusion dynamics presented a concentration gradient determined by the chemical affinity of the H2O2 with each specific dental tissue.

  10. Materials Compatibility Testing in Concentrated Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Boxwell, R.; Bromley, G.; Mason, D.; Crockett, D.; Martinez, L.; McNeal, C.; Lyles, G. (Technical Monitor)

    2000-01-01

    Materials test methods from the 1960's have been used as a starting point in evaluating materials for today's space launch vehicles. These established test methods have been modified to incorporate today's analytical laboratory equipment. The Orbital test objective was to test a wide range of materials to incorporate the revolution in polymer and composite materials that has occurred since the 1960's. Testing is accomplished in 3 stages from rough screening to detailed analytical tests. Several interesting test observations have been made during this testing and are included in the paper. A summary of the set-up, test and evaluation of long-term storage sub-scale tanks is also included. This sub-scale tank test lasted for a 7-month duration prior to being stopped due to a polar boss material breakdown. Chemical evaluations of the hydrogen peroxide and residue left on the polar boss surface identify the material breakdown quite clearly. The paper concludes with recommendations for future testing and a specific effort underway within the industry to standardize the test methods used in evaluating materials.

  11. Inactivation of rabies virus by hydrogen peroxide.

    PubMed

    Abd-Elghaffar, Asmaa A; Ali, Amal E; Boseila, Abeer A; Amin, Magdy A

    2016-02-01

    Development of safe and protective vaccines against infectious pathogens remains a challenge. Inactivation of rabies virus is a critical step in the production of vaccines and other research reagents. Beta-propiolactone (βPL); the currently used inactivating agent for rabies virus is expensive and proved to be carcinogenic in animals. This study aimed to investigate the ability of hydrogen peroxide (H2O2) to irreversibly inactivate rabies virus without affecting its antigenicity and immunogenicity in pursuit of finding safe, effective and inexpensive alternative inactivating agents. H2O2 3% rapidly inactivated a Vero cell adapted fixed rabies virus strain designated as FRV/K within 2h of exposure without affecting its antigenicity or immunogenicity. No residual infectious virus was detected and the H2O2-inactivated vaccine proved to be safe and effective when compared with the same virus harvest inactivated with the classical inactivating agent βPL. Mice immunized with H2O2-inactivated rabies virus produced sufficient level of antibodies and were protected when challenged with lethal CVS virus. These findings reinforce the idea that H2O2 can replace βPL as inactivating agent for rabies virus to reduce time and cost of inactivation process. PMID:26731189

  12. Inactivation of rabies virus by hydrogen peroxide.

    PubMed

    Abd-Elghaffar, Asmaa A; Ali, Amal E; Boseila, Abeer A; Amin, Magdy A

    2016-02-01

    Development of safe and protective vaccines against infectious pathogens remains a challenge. Inactivation of rabies virus is a critical step in the production of vaccines and other research reagents. Beta-propiolactone (βPL); the currently used inactivating agent for rabies virus is expensive and proved to be carcinogenic in animals. This study aimed to investigate the ability of hydrogen peroxide (H2O2) to irreversibly inactivate rabies virus without affecting its antigenicity and immunogenicity in pursuit of finding safe, effective and inexpensive alternative inactivating agents. H2O2 3% rapidly inactivated a Vero cell adapted fixed rabies virus strain designated as FRV/K within 2h of exposure without affecting its antigenicity or immunogenicity. No residual infectious virus was detected and the H2O2-inactivated vaccine proved to be safe and effective when compared with the same virus harvest inactivated with the classical inactivating agent βPL. Mice immunized with H2O2-inactivated rabies virus produced sufficient level of antibodies and were protected when challenged with lethal CVS virus. These findings reinforce the idea that H2O2 can replace βPL as inactivating agent for rabies virus to reduce time and cost of inactivation process.

  13. Electrochemical Visualization of Intracellular Hydrogen Peroxide at Single Cells.

    PubMed

    He, Ruiqin; Tang, Huifen; Jiang, Dechen; Chen, Hong-yuan

    2016-02-16

    In this Letter, the electrochemical visualization of hydrogen peroxide inside one cell was achieved first using a comprehensive Au-luminol-microelectrode and electrochemiluminescence. The capillary with a tip opening of 1-2 μm was filled with the mixture of chitosan and luminol, which was coated with the thin layers of polyvinyl chloride/nitrophenyloctyl ether (PVC/NPOE) and gold as the microelectrode. Upon contact with the aqueous hydrogen peroxide, hydrogen peroxide and luminol in contact with the gold layer were oxidized under the positive potential resulting in luminescence for the imaging. Due to the small diameter of the electrode, the microelectrode tip was inserted into one cell and the bright luminescence observed at the tip confirmed the visualization of intracellular hydrogen peroxide. The further coupling of oxidase on the electrode surface could open the field in the electrochemical imaging of intracellular biomolecules at single cells, which benefited the single cell electrochemical detection. PMID:26879364

  14. Catalytic hydroxylation of benzoic acid by hydrogen peroxide

    SciTech Connect

    Pulippurasseril, C.R.; Filippova, T.Yu.; Dedov, A.G.

    1992-12-31

    An effective catalytic system based on Fe(III) and surfactants is proposed for the hydroxylation of benozic acid by hydrogen peroxide in an aqueous medium at a temperature of 30-80{degrees}C. 8 refs., 1 tab.

  15. Electrochemical Visualization of Intracellular Hydrogen Peroxide at Single Cells.

    PubMed

    He, Ruiqin; Tang, Huifen; Jiang, Dechen; Chen, Hong-yuan

    2016-02-16

    In this Letter, the electrochemical visualization of hydrogen peroxide inside one cell was achieved first using a comprehensive Au-luminol-microelectrode and electrochemiluminescence. The capillary with a tip opening of 1-2 μm was filled with the mixture of chitosan and luminol, which was coated with the thin layers of polyvinyl chloride/nitrophenyloctyl ether (PVC/NPOE) and gold as the microelectrode. Upon contact with the aqueous hydrogen peroxide, hydrogen peroxide and luminol in contact with the gold layer were oxidized under the positive potential resulting in luminescence for the imaging. Due to the small diameter of the electrode, the microelectrode tip was inserted into one cell and the bright luminescence observed at the tip confirmed the visualization of intracellular hydrogen peroxide. The further coupling of oxidase on the electrode surface could open the field in the electrochemical imaging of intracellular biomolecules at single cells, which benefited the single cell electrochemical detection.

  16. Sodium Borohydride/Hydrogen Peroxide Fuel Cells For Space Application

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Deelo, M. E.; Narayanan, S. R.

    2006-01-01

    This viewgraph presentation examines Sodium Borohydride and Hydrogen Peroxide Fuel Cells as they are applied to space applications. The topics include: 1) Motivation; 2) The Sodium Borohydride Fuel Cell; 3) Sodium Borohydride Fuel Cell Test Stands; 4) Fuel Cell Comparisons; 5) MEA Performance; 6) Anode Polarization; and 7) Electrode Analysis. The benefits of hydrogen peroxide as an oxidant and benefits of sodium borohydride as a fuel are also addressed.

  17. Prediction and assignment of the FIR spectrum of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Helminger, P.; Messer, J. K.; De Lucia, F. C.; Bowman, W. C.

    1984-01-01

    Millimeter and submillimeter microwave studies are used to predict and assign the FIR rotational-torsional spectrum of hydrogen peroxide. Special attention is given to the strong Q-branch features that have recently been used by Traub and Chance to place an upper limit on the atmospheric abundance of hydrogen peroxide. In addition, 67 new transitions are reported in the 400-1000 GHz region.

  18. [Hydrogen peroxide in the surgery of hydatid cyst].

    PubMed

    Djilali, G; Mahrour, A; Oussedik, T; Abad, M; Bouguerra, T; Nekrouf, G; Belkaid, M; Souilamas, F

    1983-01-29

    Discouraged by the dangers and drawbacks of the usual scolicidal agents (formalin or strongly hypertonic saline), the authors have tried and adopted hydrogen peroxide in surgery of hydatid cysts. Liberal applications of this product on the operative field seem to be devoid of harmful effects. This, together with constant and rapid effectiveness, easy handling, low cost and wide availability should recommend hydrogen peroxide as the sole scolicidal agent in general surgery units.

  19. Hydrogen peroxide deposition and decomposition in rain and dew waters

    NASA Astrophysics Data System (ADS)

    Ortiz, Vicky; Angélica Rubio, M.; Lissi, Eduardo A.

    Peroxides and hydrogen peroxide were determined by a fluorometric method in dew and rain collected in the atmosphere of Santiago of Chile city. The measured peroxides comprise hydrogen peroxide (the main component) and peroxides not decomposed by catalase. The collected natural peroxides readily decompose in the natural matrix, rendering difficult an estimation of the values present in real-time. In order to establish the kinetics of the process and the factors that condition their decomposition, the kinetics of the decay at several pHs and/or the presence of metal chelators were followed. The kinetics of hydrogen peroxide decomposition in the water matrix was evaluated employing the natural peroxides or hydrogen peroxide externally added. First-order kinetics was followed, with half decay times ranging from 80 to 2300 min. The addition of Fe(II) in the micromolar range increases the decomposition rate, while lowering the pH (<3) notably reduces the rate of the process. The contribution of metals to the decomposition of the peroxides in the natural waters was confirmed by the reduction in decomposition rate elicited by its treatment with Chelex-100. Dew and rain waters were collected in pre-acidified collectors, rendering values considerably higher than those measured in non-treated collectors. This indicates that acidification can be proposed as an easy procedure to stabilize the samples, reducing its decomposition during collection time and the time elapsed between collection and analysis. The weighted average concentration for total peroxides measured in pre-treated collectors was 5.4 μM in rains and 2.2 μM in dews.

  20. Generation of hydrogen peroxide in a shorted fuel cell

    SciTech Connect

    Webb, S.P.; McIntyre, J.A.

    1996-12-31

    Hydrogen peroxide is a {open_quotes}green{close_quotes} chemical with a well-assured future. As such, significant growth in demand is predicted for this material. To meet this growth, new technologies of manufacture are being contemplated to compete with the established Anthraquinone process. Some of these new methods seek the niche market of on-site generation of hydrogen peroxide. One good example of this is Dow`s caustic/peroxide generation scheme for the bleaching of paper pulp. Others rely on externally-supplied electrical power in an electrochemical reactor scheme, where peroxide may be generated additionally in neutral or acidic solution. It has long been realized that the chemical potential of the reactants themselves can be used in a controlled manner in an electrolytic cell. This is the basis of fuel cells (to generate electrical power) and has been extended to the synthesis of useful chemical species, either using solid polymer electrolytes or active oxygen transporting membranes. Use has also been made of the inherent chemical potential in H{sub 2}/O{sub 2} reactions to produce hydrogen peroxide. This reactor utilized a liquid phase cathode with dissolved air or oxygen to produce small concentrations of peroxide in a fixed volume. In fact, most schemes for the direct, electrochemical production of peroxide from hydrogen and oxygen yield low, millimolar peroxide concentrations. This paper describes the development of a scalable, segmented-flow, shorted fuel cell for the generation of greater than 1 w/o hydrogen peroxide. Three areas are of major importance in the development of a continuous, peroxide-forming reactor: the reactor design, catalyst choice and application, and the operating parameters for the reactor. The cathode catalyst is probably the single most important part. Operating parameters include such basics as temperature, pressure, gas flow rate, and liquid flow rate. Each of these topics will be discussed.

  1. Atmospheric hydrogen peroxide and Eoarchean iron formations.

    PubMed

    Pecoits, E; Smith, M L; Catling, D C; Philippot, P; Kappler, A; Konhauser, K O

    2015-01-01

    It is widely accepted that photosynthetic bacteria played a crucial role in Fe(II) oxidation and the precipitation of iron formations (IF) during the Late Archean-Early Paleoproterozoic (2.7-2.4 Ga). It is less clear whether microbes similarly caused the deposition of the oldest IF at ca. 3.8 Ga, which would imply photosynthesis having already evolved by that time. Abiological alternatives, such as the direct oxidation of dissolved Fe(II) by ultraviolet radiation may have occurred, but its importance has been discounted in environments where the injection of high concentrations of dissolved iron directly into the photic zone led to chemical precipitation reactions that overwhelmed photooxidation rates. However, an outstanding possibility remains with respect to photochemical reactions occurring in the atmosphere that might generate hydrogen peroxide (H2 O2 ), a recognized strong oxidant for ferrous iron. Here, we modeled the amount of H2 O2 that could be produced in an Eoarchean atmosphere using updated solar fluxes and plausible CO2 , O2 , and CH4 mixing ratios. Irrespective of the atmospheric simulations, the upper limit of H2 O2 rainout was calculated to be <10(6) molecules cm(-2) s(-1) . Using conservative Fe(III) sedimentation rates predicted for submarine hydrothermal settings in the Eoarchean, we demonstrate that the flux of H2 O2 was insufficient by several orders of magnitude to account for IF deposition (requiring ~10(11) H2 O2 molecules cm(-2) s(-1) ). This finding further constrains the plausible Fe(II) oxidation mechanisms in Eoarchean seawater, leaving, in our opinion, anoxygenic phototrophic Fe(II)-oxidizing micro-organisms the most likely mechanism responsible for Earth's oldest IF. PMID:25324177

  2. Atmospheric hydrogen peroxide and Eoarchean iron formations.

    PubMed

    Pecoits, E; Smith, M L; Catling, D C; Philippot, P; Kappler, A; Konhauser, K O

    2015-01-01

    It is widely accepted that photosynthetic bacteria played a crucial role in Fe(II) oxidation and the precipitation of iron formations (IF) during the Late Archean-Early Paleoproterozoic (2.7-2.4 Ga). It is less clear whether microbes similarly caused the deposition of the oldest IF at ca. 3.8 Ga, which would imply photosynthesis having already evolved by that time. Abiological alternatives, such as the direct oxidation of dissolved Fe(II) by ultraviolet radiation may have occurred, but its importance has been discounted in environments where the injection of high concentrations of dissolved iron directly into the photic zone led to chemical precipitation reactions that overwhelmed photooxidation rates. However, an outstanding possibility remains with respect to photochemical reactions occurring in the atmosphere that might generate hydrogen peroxide (H2 O2 ), a recognized strong oxidant for ferrous iron. Here, we modeled the amount of H2 O2 that could be produced in an Eoarchean atmosphere using updated solar fluxes and plausible CO2 , O2 , and CH4 mixing ratios. Irrespective of the atmospheric simulations, the upper limit of H2 O2 rainout was calculated to be <10(6) molecules cm(-2) s(-1) . Using conservative Fe(III) sedimentation rates predicted for submarine hydrothermal settings in the Eoarchean, we demonstrate that the flux of H2 O2 was insufficient by several orders of magnitude to account for IF deposition (requiring ~10(11) H2 O2 molecules cm(-2) s(-1) ). This finding further constrains the plausible Fe(II) oxidation mechanisms in Eoarchean seawater, leaving, in our opinion, anoxygenic phototrophic Fe(II)-oxidizing micro-organisms the most likely mechanism responsible for Earth's oldest IF.

  3. Hydrogen Peroxide in Groundwater at Rifle, Colorado

    NASA Astrophysics Data System (ADS)

    Yuan, X.; Nico, P. S.; Williams, K. H.; Hobson, C.; Davis, J. A.

    2015-12-01

    Hydrogen peroxide (H2O2), as a reactive transient presenting ubiquitously in natural surface waters, can react with a large suite of biologically important and redox-sensitive trace elements. The dominant source of H2O2 in natural waters has long been thought to be photo-oxidation of chromophoric dissolved organic matter by molecular oxygen to produce superoxide radical, which then proceeds via dismutation to generate H2O2. However, recent studies have indicated that dark production of H2O2 in deep seawater, principally by biological production, is potentially on par with photochemical generation. Here, we present evidence for abiotic dark generation of H2O2 in groundwater in an alluvial aquifer adjacent to the Colorado River near Rifle, CO. Background H2O2 concentrations were determined in situ using a sensitive chemiluminescence-based method. Our results suggest H2O2 concentrations ranged from lower than the detection limit (1 nM) to 54 nM in different monitoring wells at the site, and the concentrations exhibited close correlations with profiles of dissolved oxygen and iron concentrations in the wells, indicating a possible metal redox cycling mechanism. In addition, dissolved natural organic matter, which could potentially coordinate the interconversion of ferric and ferrous species, might also play an important role in H2O2 formation. While biologically mediated activities have been recognized as the major sink of H2O2, the detected H2O2 pattern in groundwater suggests the existence of a balance between H2O2 source and decay, which potentially involves a cascade of biogeochemically significant processes, including the interconversion of ferrous/ferric species, the generation of more reactive oxygen species, such as hydroxyl radical, the depletion of dissolved oxygen and further transformation of natural organic matter and other chemical pollutants.

  4. Localised hydrogen peroxide sensing for reproductive health

    NASA Astrophysics Data System (ADS)

    Purdey, Malcolm S.; Schartner, Erik P.; Sutton-McDowall, Melanie L.; Ritter, Lesley J.; Thompson, Jeremy G.; Monro, Tanya M.; Abell, Andrew D.

    2015-05-01

    The production of reactive oxygen species (ROS) is known to affect the developmental competence of embryos. Hydrogen peroxide (H2O2) an important reactive oxygen species, is also known to causes DNA damage and defective sperm function. Current techniques require incubating a developing embryo with an organic fluorophore which is potentially hazardous for the embryo. What we need is a localised ROS sensor which does not require fluorophores in solution and hence will allow continuous monitoring of H2O2 production without adversely affect the development of the embryo. Here we report studies on such a fibre-based sensor for the detection of H2O2 that uses a surface-bound aryl boronate fluorophore carboxyperoxyfluor-1(CPF1). Optical fibres present a unique platform due to desirable characteristics as dip sensors in biological solutions. Attempts to functionalise the fibre tips using polyelectrolyte layers and (3-aminopropyl)triethoxysilane (APTES) coatings resulted in a limited signal and poor fluorescent response to H2O2 due to a low tip surface density of the fluorophore. To increase the surface density, CPF1 was integrated into a polymer matrix formed on the fibre tip by a UV-catalysed polymerisation process of acrylamide onto a methacrylate silane layer. The polyacrylamide containing CPF1 gave a much higher surface density than previous surface attachment methods and the sensor was found to effectively detect H2O2. Using this method, biologically relevant concentrations of H2O2 were detected, enabling remote sensing studies into ROS releases from embryos throughout early development.

  5. Different Modes of Hydrogen Peroxide Action During Seed Germination.

    PubMed

    Wojtyla, Łukasz; Lechowska, Katarzyna; Kubala, Szymon; Garnczarska, Małgorzata

    2016-01-01

    Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins, and ethylene, and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and aging.

  6. Different Modes of Hydrogen Peroxide Action During Seed Germination.

    PubMed

    Wojtyla, Łukasz; Lechowska, Katarzyna; Kubala, Szymon; Garnczarska, Małgorzata

    2016-01-01

    Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins, and ethylene, and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and aging. PMID:26870076

  7. Different Modes of Hydrogen Peroxide Action During Seed Germination

    PubMed Central

    Wojtyla, Łukasz; Lechowska, Katarzyna; Kubala, Szymon; Garnczarska, Małgorzata

    2016-01-01

    Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins, and ethylene, and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and aging. PMID:26870076

  8. Microbiologic evaluation of a hydrogen peroxide sterilization system.

    PubMed

    Wilkins, D L; Chung, P Y; Tsuchiya, P Y; Wessels, I F; Zuccarelli, A J

    1994-01-01

    The reliability of chemical sterilizers (acetone and/or 30-percent hydrogen peroxide at 25 degrees C and at 60 degrees C) was tested against Bacillus subtilis inoculated onto glass slides, commercial biological indicator discs (Bacillus stearothermophilus and B. subtilis), and B. subtilis spore survival. Acetone alone was not sporicidal. Hydrogen-peroxide-sterilized glass slides were sterile after 5 minutes. The indicator discs required 25 minutes at 25 degrees C, and less than 3 minutes at 60 degrees C (P < .0001). The D value of B. subtilis in 27-percent hydrogen peroxide at 25 degrees C is 2 minutes, with z values of 22 degrees C and 26 degrees C at 25 degrees C and 40 degrees C, respectively. For delicate instruments, a 30-percent peroxide solution followed by an acetone rinse provides an effective alternative to classic heat sterilization.

  9. Probing skin interaction with hydrogen peroxide using diffuse reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Zonios, George; Dimou, Aikaterini; Galaris, Dimitrios

    2008-01-01

    Hydrogen peroxide is an important oxidizing agent in biological systems. In dermatology, it is frequently used as topical antiseptic, it has a haemostatic function, it can cause skin blanching, and it can facilitate skin tanning. In this work, we investigated skin interaction with hydrogen peroxide, non-invasively, using diffuse reflectance spectroscopy. We observed transient changes in the oxyhaemoglobin and deoxyhaemoglobin concentrations as a result of topical application of dilute H2O2 solutions to the skin, with changes in deoxyhaemoglobin concentration being more pronounced. Furthermore, we did not observe any appreciable changes in melanin absorption properties as well as in the skin scattering properties. We also found no evidence for production of oxidized haemoglobin forms. Our observations are consistent with an at least partial decomposition of hydrogen peroxide within the stratum corneum and epidermis, with the resulting oxygen and/or remaining hydrogen peroxide inducing vasoconstriction to dermal blood vessels and increasing haemoglobin oxygen saturation. An assessment of the effects of topical application of hydrogen peroxide to the skin may serve as the basis for the development of non-invasive techniques to measure skin antioxidant capacity and also may shed light onto skin related disorders such as vitiligo.

  10. Improvement of adventitious root formation in flax using hydrogen peroxide.

    PubMed

    Takáč, Tomáš; Obert, Bohuš; Rolčík, Jakub; Šamaj, Jozef

    2016-09-25

    Flax (Linum usitatissimum L.) is an important crop for the production of oil and fiber. In vitro manipulations of flax are used for genetic improvement and breeding while improvements in adventitious root formation are important for biotechnological programs focused on regeneration and vegetative propagation of genetically valuable plant material. Additionally, flax hypocotyl segments possess outstanding morphogenetic capacity, thus providing a useful model for the investigation of flax developmental processes. Here, we investigated the crosstalk between hydrogen peroxide and auxin with respect to reprogramming flax hypocotyl cells for root morphogenetic development. Exogenous auxin induced the robust formation of adventitious roots from flax hypocotyl segments while the addition of hydrogen peroxide further enhanced this process. The levels of endogenous auxin (indole-3-acetic acid; IAA) were positively correlated with increased root formation in response to exogenous auxin (1-Naphthaleneacetic acid; NAA). Histochemical staining of the hypocotyl segments revealed that hydrogen peroxide and peroxidase, but not superoxide, were positively correlated with root formation. Measurements of antioxidant enzyme activities showed that endogenous levels of hydrogen peroxide were controlled by peroxidases during root formation from hypocotyl segments. In conclusion, hydrogen peroxide positively affected flax adventitious root formation by regulating the endogenous auxin levels. Consequently, this agent can be applied to increase flax regeneration capacity for biotechnological purposes such as improved plant rooting. PMID:26921706

  11. Improvement of adventitious root formation in flax using hydrogen peroxide.

    PubMed

    Takáč, Tomáš; Obert, Bohuš; Rolčík, Jakub; Šamaj, Jozef

    2016-09-25

    Flax (Linum usitatissimum L.) is an important crop for the production of oil and fiber. In vitro manipulations of flax are used for genetic improvement and breeding while improvements in adventitious root formation are important for biotechnological programs focused on regeneration and vegetative propagation of genetically valuable plant material. Additionally, flax hypocotyl segments possess outstanding morphogenetic capacity, thus providing a useful model for the investigation of flax developmental processes. Here, we investigated the crosstalk between hydrogen peroxide and auxin with respect to reprogramming flax hypocotyl cells for root morphogenetic development. Exogenous auxin induced the robust formation of adventitious roots from flax hypocotyl segments while the addition of hydrogen peroxide further enhanced this process. The levels of endogenous auxin (indole-3-acetic acid; IAA) were positively correlated with increased root formation in response to exogenous auxin (1-Naphthaleneacetic acid; NAA). Histochemical staining of the hypocotyl segments revealed that hydrogen peroxide and peroxidase, but not superoxide, were positively correlated with root formation. Measurements of antioxidant enzyme activities showed that endogenous levels of hydrogen peroxide were controlled by peroxidases during root formation from hypocotyl segments. In conclusion, hydrogen peroxide positively affected flax adventitious root formation by regulating the endogenous auxin levels. Consequently, this agent can be applied to increase flax regeneration capacity for biotechnological purposes such as improved plant rooting.

  12. Fluorescence ratiometric sensor for trace vapor detection of hydrogen peroxide.

    PubMed

    Xu, Miao; Han, Ji-Min; Wang, Chen; Yang, Xiaomei; Pei, Jian; Zang, Ling

    2014-06-11

    Trace vapor detection of hydrogen peroxide (H2O2) represents a practical approach to nondestructive detection of peroxide-based explosives, including liquid mixtures of H2O2 and fuels and energetic peroxide derivatives, such as triacetone triperoxide (TATP), diacetone diperoxide (DADP), and hexamethylene triperoxide diamine (HMTD). Development of a simple chemical sensor system that responds to H2O2 vapor with high reliability and sufficient sensitivity (reactivity) remains a challenge. We report a fluorescence ratiometric sensor molecule, diethyl 2,5-bis((((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)oxy)carbonyl)amino)terephthalate (DAT-B), for H2O2 that can be fabricated into an expedient, reliable, and sensitive sensor system suitable for trace vapor detection of H2O2. DAT-B is fluorescent in the blue region, with an emission maximum at 500 nm in the solid state. Upon reaction with H2O2, DAT-B is converted to an electronic "push-pull" structure, diethyl 2,5-diaminoterephthalate (DAT-N), which has an emission peak at a longer wavelength centered at 574 nm. Such H2O2-mediated oxidation of aryl boronates can be accelerated through the addition of an organic base such as tetrabutylammonium hydroxide (TBAH), resulting in a response time of less than 0.5 s under 1 ppm of H2O2 vapor. The strong overlap between the absorption band of DAT-N and the emission band of DAT-B enables efficient Förster resonance energy transfer (FRET), thus allowing further enhancement of the sensing efficiency of H2O2 vapor. The detection limit of a drop-cast DAT-B/TBAH film was projected to be 7.7 ppb. By combining high sensitivity and selectivity, the reported sensor system may find broad application in vapor detection of peroxide-based explosives and relevant chemical reagents through its fabrication into easy-to-use, cost-effective kits. PMID:24801730

  13. The electrochemistry of SIMFUEL in dilute alkaline hydrogen peroxide solutions

    NASA Astrophysics Data System (ADS)

    Goldik, Jon

    of the H2O2 molecule. The next set of experiments focused on the effects of dissolved bicarbonate and carbonate ions on the rates and mechanism of H2O2 reduction on SIMFUEL. The reduction kinetics were found to be influenced by the dissolved carbonate ions. The formation of hydrated UVI species on the electrode surface is avoided in carbonate solutions, allowing H2O2 reduction to proceed at more positive potentials than in carbonate-free solutions. At more negative potentials, the adsorption of carbonate ions on the active reduction sites inhibits the H2O 2 reduction reaction. Over a narrow potential region, the reduction of peroxide is catalyzed by coadsorption of H2O2 and HCO3-/CO32-. The pH dependence of the H2O2 reduction reaction is more complex in carbonate solutions than in solutions that do not contain carbonate. This can be attributed to the displacement of inhibiting CO32-/HCO 3- adsorbed ions by OH-. Under natural corrosion conditions, steady-state corrosion potentials were found to be very similar to those measured in carbonate-free electrolytes. XPS evidence shows that the electrode surface contains a much lower UVI contribution at high corrosion potentials, confirming that the formation of hydrated U VI species is prevented. The influence of carbonate on the anodic dissolution mechanism was also examined in a limited number of experiments. The onset of dissolution occurs at more negative potentials as the carbonate concentration is increased, indicating an acceleration of the SIMFUEL dissolution reaction. EIS evidence suggests that adsorbed carbonate and bicarbonate species are involved in the dissolution mechanism. Lastly, the influence of the dopant elements in SIMFUEL (which chemically simulate fission products in spent fuel) on the rate of hydrogen peroxide reduction was studied. Using steady-state polarization, the reaction rate was found to increase with the doping level of the SIMFUEL, under transport-compensated conditions. The noble metal

  14. 14 CFR 420.66 - Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored... Responsibilities of a Licensee § 420.66 Separation distance requirements for storage of hydrogen peroxide... section for each explosive hazard facility storing: (1) Hydrogen peroxide in concentrations of...

  15. 14 CFR 420.66 - Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored... Responsibilities of a Licensee § 420.66 Separation distance requirements for storage of hydrogen peroxide... section for each explosive hazard facility storing: (1) Hydrogen peroxide in concentrations of...

  16. Selective electrochemical generation of hydrogen peroxide from water oxidation

    DOE PAGES

    Viswanathan, Venkatasubramanian; Hansen, Heine A.; Norskov, Jens K.

    2015-10-08

    Water is a life-giving source, fundamental to human existence, yet over a billion people lack access to clean drinking water. The present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, wemore » show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e– water oxidation to H2O2 and the 4e– oxidation to O2. We show that materials which bind oxygen intermediates sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. Furthermore, we present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively.« less

  17. Selective electrochemical generation of hydrogen peroxide from water oxidation

    SciTech Connect

    Viswanathan, Venkatasubramanian; Hansen, Heine A.; Norskov, Jens K.

    2015-10-08

    Water is a life-giving source, fundamental to human existence, yet over a billion people lack access to clean drinking water. The present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, we show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e– water oxidation to H2O2 and the 4e– oxidation to O2. We show that materials which bind oxygen intermediates sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. Furthermore, we present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively.

  18. Selective Electrochemical Generation of Hydrogen Peroxide from Water Oxidation.

    PubMed

    Viswanathan, Venkatasubramanian; Hansen, Heine A; Nørskov, Jens K

    2015-11-01

    Water is a life-giving source, fundamental to human existence, yet over a billion people lack access to clean drinking water. The present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, we show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e(-) water oxidation to H2O2 and the 4e(-) oxidation to O2. We show that materials which bind oxygen intermediates sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. We present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively.

  19. Hydrogen peroxide sensor using laser grade dye Rhodamine B

    NASA Astrophysics Data System (ADS)

    Pattanaik, Amitansu; Sahare, P. D.; Nanda, Maitreyee

    2007-11-01

    Many chemical sensors based on fluorescence spectroscopy have been reported in applications, ranging from biomedical and environmental monitoring to industrial process control. In these diverse applications, the analyte can be probed directly, by measuring its intrinsic absorption, or by incorporating some transduction mechanism such as reagent chemistry to enhance sensitivity and selectivity. Hydrogen Peroxide is a colorless liquid. It is a common oxidizing and bleaching agent. It plays an important role in High Power Laser such as Chemical Oxygen Iodine Laser (COIL). As it is on the Hazardous substance list and on the special health hazard substance list, detection of Hydrogen Peroxide is of great importance. In the present study the detection of hydrogen Peroxide is by fluorescence quenching of laser grade dye Rhodamine B. Estimation of rate constant of the bimolecular quenching reaction is made.

  20. Cathodic electrocatalyst layer for electrochemical generation of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Rhodes, Christopher P. (Inventor); Tennakoon, Charles L. K. (Inventor); Singh, Waheguru Pal (Inventor); Anderson, Kelvin C. (Inventor)

    2011-01-01

    A cathodic gas diffusion electrode for the electrochemical production of aqueous hydrogen peroxide solutions. The cathodic gas diffusion electrode comprises an electrically conductive gas diffusion substrate and a cathodic electrocatalyst layer supported on the gas diffusion substrate. A novel cathodic electrocatalyst layer comprises a cathodic electrocatalyst, a substantially water-insoluble quaternary ammonium compound, a fluorocarbon polymer hydrophobic agent and binder, and a perfluoronated sulphonic acid polymer. An electrochemical cell using the novel cathodic electrocatalyst layer has been shown to produce an aqueous solution having between 8 and 14 weight percent hydrogen peroxide. Furthermore, such electrochemical cells have shown stable production of hydrogen peroxide solutions over 1000 hours of operation including numerous system shutdowns.

  1. Oxidative desulfurization of Tufanbeyli coal by hydrogen peroxide solution

    SciTech Connect

    Guru, M.; Sarioz, B.V.; Cakanyildirim, C.

    2008-07-01

    It is becoming popular to use fossil fuels efficiently since the necessary energy is mostly supplied from fossil fuels. Altough there are high lignite reserves, high sulfur content limits the efficient use of them. In this article, we aimed to convert combustible sulfur in coal to non-combustible sulfate form in the ash by oxidizing it with a hydrogen peroxide solution. The parameters affecting the sulfur conversion were determined to be: hydrogen peroxide concentration, reaction time, mean particle size at constant room temperature and shaking rate. The maximum desulfurization efficiency reached was 74% of the original combustible sulfur with 15% (w/w) hydrogen peroxide solution, 12 hours of reaction time, and 0.25 mm mean particle size.

  2. Hydrogen Peroxide Gas Generator Cycle with a Reciprocating Pump

    SciTech Connect

    Whitehead, J C

    2002-06-11

    A four-chamber piston pump is powered by decomposed 85% hydrogen peroxide. The performance envelope of the evolving 400 gram pump has been expanded to 172 cc/s water flow at discharge pressures near 5 MPa. A gas generator cycle system using the pump has been tested under similar conditions of pressure and flow. The powerhead gas is derived from a small fraction of the pumped hydrogen peroxide, and the system starts from tank pressures as low as 0.2 MPa. The effects of steam condensation on performance have been evaluated.

  3. Distillation Kinetics of Solid Mixtures of Hydrogen Peroxide and Water and the Isolation of Pure Hydrogen Peroxide in Ultrahigh Vacuum

    NASA Technical Reports Server (NTRS)

    Teolis, B. D.; Baragiola, R. A.

    2006-01-01

    We present results of the growth of thin films of crystalline H2O2 and H2O2.2H2O (dihydrate) in ultrahigh vacuum by distilling an aqueous solution of hydrogen peroxide. We traced the process using infrared reflectance spectroscopy, mass loss on a quartz crystal microbalance, and in a few cases ultraviolet-visible reflectance. We find that the different crystalline phases-water, dihydrate, and hydrogen peroxide-have very different sublimation rates, making distillation efficient to isolate the less volatile component, crystalline H2O2.

  4. Oxygen Mass Flow Rate Generated for Monitoring Hydrogen Peroxide Stability

    NASA Technical Reports Server (NTRS)

    Ross, H. Richard

    2002-01-01

    Recent interest in propellants with non-toxic reaction products has led to a resurgence of interest in hydrogen peroxide for various propellant applications. Because peroxide is sensitive to contaminants, material interactions, stability and storage issues, monitoring decomposition rates is important. Stennis Space Center (SSC) uses thermocouples to monitor bulk fluid temperature (heat evolution) to determine reaction rates. Unfortunately, large temperature rises are required to offset the heat lost into the surrounding fluid. Also, tank penetration to accomodate a thermocouple can entail modification of a tank or line and act as a source of contamination. The paper evaluates a method for monitoring oxygen evolution as a means to determine peroxide stability. Oxygen generation is not only directly related to peroxide decomposition, but occurs immediately. Measuring peroxide temperature to monitor peroxide stability has significant limitations. The bulk decomposition of 1% / week in a large volume tank can produce in excess of 30 cc / min. This oxygen flow rate corresponds to an equivalent temperature rise of approximately 14 millidegrees C, which is difficult to measure reliably. Thus, if heat transfer were included, there would be no temperature rise. Temperature changes from the surrounding environment and heat lost to the peroxide will also mask potential problems. The use of oxygen flow measurements provides an ultra sensitive technique for monitoring reaction events and will provide an earlier indication of an abnormal decomposition when compared to measuring temperature rise.

  5. Assessment of The Compatibility of Composite Materials With High-Test Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Gostowski, Rudy; Griffin, Dennis E. (Technical Monitor)

    2000-01-01

    The compatibility of composite materials with high-test hydrogen peroxide (HTP) was assessed using various chemical and mechanical techniques. Methods included classical schemes combining concentration assay with accelerated aging by means of a heated water bath. Exothermic reactivity was observed using Isothermal Microcalorimetry. Mechanical Properties testing determined degradation of the composite material. Photoacoustic Infrared Spectroscopy was used to monitor chemical alteration of the resin matrix. Other materials were examined including some polymers and metals.

  6. Hydrogen peroxide evolution during V-UV photolysis of water.

    PubMed

    Azrague, Kamal; Bonnefille, Eric; Pradines, Vincent; Pimienta, Véronique; Oliveros, Esther; Maurette, Marie-Thérèse; Benoit-Marquié, Florence

    2005-05-01

    Hydrogen peroxide evolution during the vacuum-ultraviolet (V-UV, 172 nm) photolysis of water is considerably affected by the presence of oxalic acid (employed as a model water pollutant) and striking differences are observed in the absence and in the presence of dioxygen.

  7. Hydrogen peroxide as a fungicide for fish culture

    USGS Publications Warehouse

    Dawson, V.K.; Rach, J.J.; Schreier, T.M.

    1994-01-01

    Antifungal agents are needed to maintain healthy stocks of fish in the intensive culture systems currently employed in fish hatcheries. Malachite green has been the most widely used antifungal agent; however, its potential for producing teratology in animals and fish precludes further use in fish culture. Preliminary studies at the National Fisheries Research Center, La Crosse, WI, USA (La Crosse Center) indicate that hydrogen peroxide is effective for control of Saprolegnia sp. fungus on incubating eggs of rainbow trout. It is also effective against a wide variety of other organisms such as bacteria, yeasts, viruses, and spores, and has been proposed as a treatment for sea lice on salmon. Hydrogen peroxide and its primary decomposition products, oxygen and water, are not systemic poisons and are considered environmentally compatible. In response to a petition from the La Crosse Center, the U.S. Food and Drug Administration (FDA) recently classified hydrogen peroxide as a 'low regulatory priority' when used for control of fungus on fish and fish eggs. Preliminary tests conducted at the La Crosse Center suggest that prophylactic treatments of 250 to 500 ppm (based on 100% active ingredient) for 15 minutes every other day will inhibit fungal infections on healthy rainbow trout (Oncorhynchus mykiss) eggs. This treatment regime also seems to inhibit fungal development and increase hatching success among infected eggs. Efficacy and safety of hydrogen peroxide as a fungicide for fish are currently being evaluated.

  8. Hydrogen peroxide in sulfuric acid extraction of uranium ores

    SciTech Connect

    DeVries, F.W.

    1984-01-10

    Uranium can be extracted from its ores at a pH of 2.5 to 5.5 using sulfuric acid, hydrogen peroxide, trace of iron and a sulfate. The extraction process is applicable to both tank leaching of conventionally mined ores and in situ leaching.

  9. Inactivation of penicillin G in milk using hydrogen peroxide.

    PubMed

    Hanway, W H; Hansen, A P; Anderson, K L; Lyman, R L; Rushing, J E

    2005-02-01

    Milk antibiotic residues have been a public concern in recent years. The Grade A Pasteurized Milk Ordinance mandates that raw Grade A milk will test negative for beta-lactam antibiotic residues before processing. The purpose of this research was to investigate the ability of various levels of peroxide and heat to inactivate penicillin G in raw milk. Whole milk spiked to a mean of 436 +/- 15.1 (standard error of the mean) ppb of potassium penicillin G was treated with hydrogen peroxide at levels of 0.0, 0.09, 0.17, and 0.34%. Samples at each peroxide level (n = 6 per treatment) were treated as follows: 1) incubated at 54.4 degrees C for 3 h, 2) pasteurized at 62.8 degrees C for 30 min, 3) incubated and pasteurized as in treatments 1 and 2, or 4) received no further treatment. A beta-lactam competitive microbial receptor assay was used for quantification of penicillin G. Concentrations of penicillin in selected samples were determined by HPLC for a comparison of test methods. Treatments were evaluated relative to their ability to reduce milk penicillin G levels to below the safe level of 5 ppb. The 0.09% hydrogen peroxide level was ineffective for all treatments. Hydrogen peroxide at 0.17% lowered the mean penicillin G (+/- SEM) from 436 +/- 15.1 to 6 +/- 1.49 ppb using the incubated and pasteurized heat treatment. The 0.34% concentration of hydrogen peroxide was the most effective, inactivating penicillin G to a level well below the safe level of 5 ppb with the pasteurized heat treatment, with or without incubation.

  10. Toxicity of hydrogen peroxide treatments to rainbow trout eggs

    USGS Publications Warehouse

    Gaikowski, M.P.; Rach, J.J.; Olson, J.J.; Ramsay, R.T.

    1998-01-01

    Hydrogen peroxide treatments of 0, 500, 1,000, and 3,000 I?L/L, concentrations that were multiples of the Low Regulatory Priority limit of 500 I?L/L, were administered for 15 min every weekday (Mondaya??Friday) to eggs of rainbow trout Oncorhynchus mykiss and steelhead (anadromous rainbow trout) to determine the margin of safety existing for standard egg treatments. All untreated and treated eggs remained free of fungal infection throughout incubation. Hydrogen peroxide treatment reduced the mean percent hatch of rainbow trout eggs by 1.4a??5.9% among those treated at 500 I?L/L, 6.8a??15.4% among those treated at 1,000 I?L/L, and 13.2a??25.3% among those treated at 3,000 I?L/L. Mean percent hatch of rainbow trout eggs treated at 1,000 I?L H2O2/L was 7% lower than that for eggs treated at 500 I?L H2O2/L. Mean percent hatch of Skamania strain steelhead was significantly reduced by hydrogen peroxide treatment, whereas the mean percent hatch of Ganaraska strain steelhead was similar to the mean percent hatch of rainbow trout eggs. Daily percent mortality of rainbow trout eggs increased significantly from day 6 to day 10 (78a??135 daily temperature units, DTUsA?C) of incubation. Discontinuing hydrogen peroxide treatments to Skamania strain steelhead eggs from day 7 to day 11 (78a??105 DTUsA?C) of incubation significantly increased the probability of eggs reaching the eyed egg stage. The mean percent hatch of rainbow trout eggs treated with hydrogen peroxide at concentrations up to 1,000 I?L/L may be increased if no treatments are administered between 70 and 140 DTUsA?C. Mortality of sac fry was not observed at hydrogen peroxide concentrations of 1,000 I?L/L or lower. Fish culturists should be aware that other species or strains may be more sensitive than rainbow trout. Other species and strains should be initially treated with hydrogen peroxide at 500 I?L/L until monitoring of egg mortality identifies the presence or absence of a sensitive period.

  11. Oxygen dependency of one-electron reactions generating ascorbate radicals and hydrogen peroxide from ascorbic acid.

    PubMed

    Boatright, William L

    2016-04-01

    The effect of oxygen on the two separate one-electron reactions involved in the oxidation of ascorbic acid was investigated. The rate of ascorbate radical (Asc(-)) formation (and stability) was strongly dependent on the presence of oxygen. A product of ascorbic acid oxidation was measurable levels of hydrogen peroxide, as high as 32.5 μM from 100 μM ascorbic acid. Evidence for a feedback mechanism where hydrogen peroxide generated during the oxidation of ascorbic acid accelerates further oxidation of ascorbic acid is also presented. The second one-electron oxidation reaction of ascorbic acid leading to the disappearance of Asc(-) was also strongly inhibited in samples flushed with argon. In the range of 0.05-1.2 mM ascorbic acid, maximum levels of measurable hydrogen peroxide were achieved with an initial concentration of 0.2 mM ascorbic acid. Hydrogen peroxide generation was greatly diminished at ascorbic acid levels of 0.8 mM or above.

  12. Hydrogen peroxide oxidant fuel cell systems for ultra-portable applications

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Narayanan, S. R.

    2001-01-01

    This paper will address the issues of using hydrogen peroxide as an oxidant fuel in a miniature DMFC system. Cell performance for DMFC based fuel cells operating on hydrogen peroxide will be presented and discussed.

  13. Contact Lens Solutions With Hydrogen Peroxide: To Avoid Injury, Follow All Instructions

    MedlinePlus

    ... For Consumers Consumer Updates Contact Lens Solutions With Hydrogen Peroxide: To Avoid Injury, Follow All Instructions Share Tweet ... Program . back to top Checklist for Solutions With Hydrogen Peroxide Talk to your eye-care provider before deciding ...

  14. 78 FR 73697 - New Animal Drugs; Hyaluronate Sodium; Hydrogen Peroxide; Imidacloprid and Moxidectin; Change of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ...; Hyaluronate Sodium; Hydrogen Peroxide; Imidacloprid and Moxidectin; Change of Sponsor AGENCY: Food and Drug... interest in, NADA 141-255 for PEROX-AID (hydrogen peroxide) 35% Solution to Western Chemical, Inc.,...

  15. Application of a newly developed hydrogen peroxide vapor phase sensor to HPV sterilizer.

    PubMed

    Taizo, I; Sinichi, A; Kawamura, K

    1998-01-01

    A new type of concentration sensor for hydrogen peroxide vapor has been developed by making use of a semiconductor. Output from the vapor sensor has been shown to have a good linear relationship with the logarithm of the concentration of hydrogen peroxide vapor. Concentration of hydrogen peroxide vapor introduced into the sterilization chamber could be kept constant by monitoring the concentration of the hydrogen peroxide vapor continuously and controlling the vapor supply. Temperature and humidity have also been kept constant. D-values for B. stearothermophilus ATCC 12980 at various concentrations of hydrogen peroxide vapor have been determined by using the combination system of the hydrogen peroxide vapor sensor, the hydrogen peroxide vapor supplier, thermosensor and humidity sensor. D-values at the temperature of 30 degrees C and the absolute humidity of 0.7 mg H2O/L thus obtained, were 0.2 minutes at hydrogen peroxide concentration of 600 ppm and 1.2 minutes at 200 ppm at the temperature of 30 degrees C and 0.7 mg/L absolute humidity. D-values for B. stearothermophilus ATCC 12980 at various temperatures, humidity and levels of hydrogen peroxide concentration have also been determined. These fundamental data indicate that the sterilization by hydrogen peroxide vapor can be validated as precisely as steam sterilization by measuring and controlling the concentration of hydrogen peroxide vapor using a combination of the hydrogen peroxide concentration sensor and the vapor generator. Influence of temperature and humidity have also been studied. The hydrogen peroxide sensor has been calibrated and standardized by using the standard hydrogen peroxide vapor whose concentration has been determined by calculating partial pressure of hydrogen peroxide over the water-hydrogen peroxide solution. PMID:9542409

  16. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  17. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Silver nitrate and hydrogen peroxide solution. 172... FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely...

  18. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  19. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  20. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  1. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Silver nitrate and hydrogen peroxide solution. 172... Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely used in accordance with the...

  2. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  3. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  4. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Silver nitrate and hydrogen peroxide solution. 172... FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely...

  5. 40 CFR 180.1197 - Hydrogen peroxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Hydrogen peroxide; exemption from the... Exemptions From Tolerances § 180.1197 Hydrogen peroxide; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of hydrogen peroxide in or on...

  6. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Silver nitrate and hydrogen peroxide solution. 172... FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely...

  7. 21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Silver nitrate and hydrogen peroxide solution. 172... FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely...

  8. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  9. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  10. 40 CFR 415.90 - Applicability; description of the hydrogen peroxide production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrogen peroxide production subcategory. 415.90 Section 415.90 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Hydrogen Peroxide Production Subcategory § 415.90 Applicability; description of the hydrogen peroxide production subcategory. The provisions of this subpart are applicable to...

  11. Hydrogen peroxide modified sodium titanates with improved sorption capabilities

    SciTech Connect

    Nyman, May D.; Hobbs, David T.

    2009-02-24

    The sorption capabilities (e.g., kinetics, selectivity, capacity) of the baseline monosodium titanate (MST) sorbent material currently being used to sequester Sr-90 and alpha-emitting radioisotopes at the Savannah River Site are significantly improved when treated with hydrogen peroxide; either during the original synthesis of MST, or, as a post-treatment step after the MST has been synthesized. It is expected that these peroxide-modified MST sorbent materials will have significantly improved sorption capabilities for non-radioactive cations found in industrial processes and waste streams.

  12. Heme degradation upon production of endogenous hydrogen peroxide via interaction of hemoglobin with sodium dodecyl sulfate.

    PubMed

    Salehi, N; Moosavi-Movahedi, A A; Fotouhi, L; Yousefinejad, S; Shourian, M; Hosseinzadeh, R; Sheibani, N; Habibi-Rezaei, M

    2014-04-01

    In this study the hemoglobin heme degradation upon interaction with sodium dodecyl sulfate (SDS) was investigated using UV-vis and fluorescence spectroscopy, multivariate curve resolution analysis, and chemiluminescence method. Our results showed that heme degradation occurred during interaction of hemoglobin with SDS producing three fluorescent components. We showed that the hydrogen peroxide, produced during this interaction, caused heme degradation. In addition, the endogenous hydrogen peroxide was more effective in hemoglobin heme degradation compared to exogenously added hydrogen peroxide. The endogenous form of hydrogen peroxide altered oxyHb to aquamethemoglobin and hemichrome at low concentration. In contrast, the exogenous hydrogen peroxide lacked this ability under same conditions.

  13. Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.

    PubMed

    Palo, R M; Bonetti-Filho, I; Valera, M C; Camargo, C H R; Camargo, Sea; Moura-Netto, C; Pameijer, C

    2012-01-01

    The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the

  14. Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.

    PubMed

    Palo, R M; Bonetti-Filho, I; Valera, M C; Camargo, C H R; Camargo, Sea; Moura-Netto, C; Pameijer, C

    2012-01-01

    The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the

  15. Hydrogen peroxide-induced apoptosis in human gingival fibroblasts

    PubMed Central

    Gutiérrez-Venegas, Gloria; Guadarrama-Solís, Adriana; Muñoz-Seca, Carmen; Arreguín-Cano, Juan Antonio

    2015-01-01

    In the process of bleaching vital, discolored teeth, low concentrations of hydrogen peroxide (H2O2) are effective alternatives to heat-activated 30% H2O2. However, interest has been expressed in the assessment of pathological effects of long-term exposure to bleaching agents such as irritation and ulceration of the gingival or other soft tissues. The aim of the present study was to determine the effect of hydrogen peroxide on apoptosis in human gingival fibroblasts (HGF). Cytochrome c, Bcl-2, Bax, Bid and caspase-3 protein expression were detected by Western blotting. HGF cell apoptosis induced by H2O2 was both dose and time dependent. The addition of H2O2 resulted in the release of cytochrome c to the cytosol, and an increase of Caspase-3 cleavage. Data suggest that oxidative stress-induced apoptosis in HGF is intrinsic pathway involved the release of apoptotic signal from mitochondria. PMID:26884825

  16. Ozonation of deciduous wood in the presence of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Mamleeva, N. A.; Kharlanov, A. N.; Fionov, A. V.; Lunin, V. V.

    2011-10-01

    The kinetic curves of the dependence of ozone specific absorption ( Q r, sp ) upon aspen wood ozonation in the presence and absence of hydrogen peroxide are obtained. It is established that the rate of ozone and Q r, sp absorption increase in the O3/H2O2 system. It is demonstrated by ESR, IR, and UV spectroscopy of diffuse reflection that wood ozonation in the O3/H2O2 system results in the destruction of lignin aromatic and quinoid structures. The ozonation process in the presence of H2O2 is accompanied by destruction of the carbohydrate component of the lignocarbohydrate complex. We conclude that O3/H2O2 can be used in the deep delignification of wood. It is shown that the presence of hydrogen peroxide upon ozonation increases the efficiency of the process, allowing its duration and total ozone consumption to be reduced.

  17. Novel aqueous dual-channel aluminum-hydrogen peroxide battery

    NASA Astrophysics Data System (ADS)

    Marsh, Catherine; Licht, Stuart

    1994-06-01

    A dual-channel aluminum hydrogen peroxide battery is introduced with an open-circuit voltage of 1.9 volts, polarization losses of 0.9 mV cm(exp 2) mA(exp -1), and power densities of 1 W/cm(exp 2). Catholyte and anolyte cell compartments are separated by an Ir/Pd modified porous nickel cathode. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode. The battery is expressed by aluminum oxidation and aqueous solution phase hydrogen peroxide reduction for an overall battery discharge consisting of 2Al + 3H2O2 + 2OH(-) yields 2AlO2(-) + 4H2O E = 2.3 V. The search for electrical propulsion sources which fit the requirements for electrically powered vehicles has blurred the standard characteristics associated with electrochemical storage systems. Presently, electrochemical systems comprised of mechanically rechargeable primary batteries, secondary batteries, and fuel cells are candidates for electrochemical propulsion sources. While important advances in energy and power density continue for nonaqueous and molten electrolytes, aqueous electrolyte batteries often have an advantage in simplicity, conductivity, cost effectiveness, and environmental impact. Systems coupling aluminum anodes and aqueous electrolytes have been investigated. These systems include: aluminum/silver oxide, aluminum/manganese dioxide, aluminum air, aluminum/hydrogen peroxide aqueous batteries, and the recently introduced aluminum/ferricyanide and aluminum sulfur aqueous batteries. Conventional aqueous systems such as the nickel cadmium and lead-acid batteries are characterized by their relatively low energy densities and adverse environmental impact. Other systems have substantially higher theoretical energy capacities. While aluminum-silver oxide has demonstrated the highest steady-state power density, its high cost is an impediment for widespread utilization for electric propulsion.

  18. Hydrogen peroxide propulsion for smaller satellites (SSC98-VIII-1)

    SciTech Connect

    Whitehead, J C

    1998-07-13

    As satellite designs shrink, providing maneuvering and control capability falls outside the realm of available propulsion technology. While cold gas has been used on the smallest satellites, hydrogen peroxide propellant is suggested as the next step in performance and cost before hydrazine. Minimal toxicity and a small scale enable benchtop propellant preparation and development testing. Progress toward low-cost thrusters and self-pressurizing tank systems is described.

  19. SONEX-Hydrogen Peroxide, Methylhydroperoxide and Formaldehyde Measurements

    NASA Technical Reports Server (NTRS)

    Heikes, Brian

    1999-01-01

    We measured gas phase H2O2, CH3OOH, and CH2O on board the NASA DC-8 during the SONEX field mission, presented preliminary results at three scientific meetings, participated in two data workshops and contributed to joint publications of final results. The observations of peroxides and formaldehyde were instrumental in assessing odd-hydrogen radical chemistry, ozone chemistry, and in tracing meteorological transport paths.

  20. Ultraviolet absorption spectrum of hydrogen peroxide vapor. [for atmospheric abundances

    NASA Technical Reports Server (NTRS)

    Molina, L. T.; Schinke, S. D.; Molina, M. J.

    1977-01-01

    The ultraviolet absorption cross sections of hydrogen peroxide vapor have been determined over the wavelength range 210 to 350 nm at 296 K. At the longer wavelengths, the gas phase absorptivities are significantly larger than the corresponding values in condensed phase. The atmospheric H2O2 photodissociation rate for overhead sun at the earth's surface is estimated to be about 1.3 x 10 to the -5th/sec.

  1. Microsolvation of methyl hydrogen peroxide: Ab initio quantum chemical approach

    NASA Astrophysics Data System (ADS)

    Kulkarni, Anant D.; Rai, Dhurba; Bartolotti, Libero J.; Pathak, Rajeev K.

    2009-08-01

    Methyl hydrogen peroxide (MHP), one of the simplest organic hydroperoxides, is a strong oxidant, with enhanced activity in aqueous ambience. The present study investigates, at the molecular level, the role of hydrogen bonding that is conducive to cluster formation of MHP with water molecules from its peroxide end, with the methyl group remaining hydrophobic for up to five water molecules. Ab initio quantum chemical computations on MHP⋯(H2O)n, [n =1-5] are performed at second order Møller-Plesset (MP2) perturbation theory employing the basis sets 6-31G(d,p) and 6-311++G(2d,2p) to study the cluster formation of MHP with water molecules from its peroxide end and hydrophobic hydration due to the methyl group. Successive addition of water molecules alters the hydrogen bonding pattern, which leads to changes in overall cluster geometry and in turn to IR vibrational frequency shifts. Molecular co-operativity in these clusters is gauged directly through a detailed many-body interaction energy analysis. Molecular electrostatic potential maps are shown to have a bearing on predicting further growth of these clusters, which is duly corroborated through sample calculations for MHP⋯(H2O)8. Further, a continuum solvation model calculation for energetically stable clusters suggests that this study should serve as a precursor for pathways to aqueous solvation of MHP.

  2. A reaction-diffusion model of cytosolic hydrogen peroxide.

    PubMed

    Lim, Joseph B; Langford, Troy F; Huang, Beijing K; Deen, William M; Sikes, Hadley D

    2016-01-01

    As a signaling molecule in mammalian cells, hydrogen peroxide (H2O2) determines the thiol/disulfide oxidation state of several key proteins in the cytosol. Localization is a key concept in redox signaling; the concentrations of signaling molecules within the cell are expected to vary in time and in space in manner that is essential for function. However, as a simplification, all theoretical studies of intracellular hydrogen peroxide and many experimental studies to date have treated the cytosol as a well-mixed compartment. In this work, we incorporate our previously reported reduced kinetic model of the network of reactions that metabolize hydrogen peroxide in the cytosol into a model that explicitly treats diffusion along with reaction. We modeled a bolus addition experiment, solved the model analytically, and used the resulting equations to quantify the spatiotemporal variations in intracellular H2O2 that result from this kind of perturbation to the extracellular H2O2 concentration. We predict that micromolar bolus additions of H2O2 to suspensions of HeLa cells (0.8 × 10(9)cells/l) result in increases in the intracellular concentration that are localized near the membrane. These findings challenge the assumption that intracellular concentrations of H2O2 are increased uniformly throughout the cell during bolus addition experiments and provide a theoretical basis for differing phenotypic responses of cells to intracellular versus extracellular perturbations to H2O2 levels.

  3. Improving the hydrogen peroxide bleaching efficiency of aspen chemithermomechanical pulp by using chitosan.

    PubMed

    Li, Zongquan; Dou, Hongyan; Fu, Yingjuan; Qin, Menghua

    2015-11-01

    The presence of transition metals during the hydrogen peroxide bleaching of pulp results in the decomposition of hydrogen peroxide, which decreases the bleaching efficiency. In this study, chitosans were used as peroxide stabilizer in the alkaline hydrogen peroxide bleaching of aspen chemithermomechanical pulp (CTMP). The results showed that the brightness of the bleached CTMP increased 1.5% ISO by addition of 0.1% chitosan with 95% degree of deacetylation during peroxide bleaching. Transition metals in the form of ions or metal colloid particles, such as iron, copper and manganese, could be adsorbed by chitosans. Chitosans could inhibit the decomposition of hydrogen peroxide catalyzed by different transition metals under alkaline conditions. The ability of chitosans to inhibit peroxide decomposition depended on the type of transition metals, chitosan concentration and degree of deacetylation applied. The addition of chitosan slightly reduced the concentration of the hydroxyl radical formed during the hydrogen peroxide bleaching of aspen CTMP.

  4. Pentachlorophenol (PCP) degradation using heme and hydrogen peroxide

    SciTech Connect

    Chen, S.T.

    1996-11-01

    Investigations of pentachlorophenol (PCP) degradation using both biotic and abiotic methods have been extensively studied. Due to the hydrophobic nature of PCP and its toxicity, the performance of the biotic treatments varies from site to site and is not satisfactory in most cases. An abiotic method for oxidative PCP degradation in soil under unsaturated conditions and a neutral pH was found. Hydrogen peroxide was used as an oxidant and heme as a catalyst. A mechanism was proposed to describe the possible reaction of heme and peroxide at the presence of PCP. In order to ensure that heme and peroxide are the most important factors during the reaction, two screening tests were run. In order to find the best conditions of PCP degradation using heme and peroxide, a statistical technique, so-called response surface methodology (RSM), was employed and the best conditions for PCP degradation in soil were determined. In order to examine the rate and extent of PCP degradation, kinetic studies were conducted and the results showed that about 70% of PCP was degraded within the first two hours and up to 80% of PCP was degraded within one day. Up to 17% of the PCP was mineralized to carbon dioxide as well. A scaled-up experiment was also studied to confirm the results in the laboratory. The result of the scaled-up experiment showed not much difference between the laboratory and the scaled-up experiments.

  5. Durability of bleaching results achieved with 15% carbamide peroxide and 38% hydrogen peroxide in vitro.

    PubMed

    Knösel, Michael; Reus, Monika; Rosenberger, Albert; Attin, Thomas; Ziebolz, Dirk

    2011-01-01

    The aim of this study was to assess the durability of bleaching results achieved with (1) 15% carbamide peroxide home bleaching and (2) 38% hydrogen peroxide in-office bleaching. A total of 231 extracted anterior teeth were randomly divided into three groups (n = 77 in each group) with comparable mean baseline L*-values (68.24 ± 0.8): a non-bleached control group A, a 15% carbamide peroxide group B (5 bleaching intervals of 8 hours), and a 38% hydrogen peroxide group C (3 intervals of 15 minutes). Durability of bleaching was assessed by comparing CIE-L*a*b* data after intervals of 2, 4, 12, and 26 weeks from baseline. Both bleaching regimes initially produced a highly significant increase in lightness parameter L*, with no significant difference between the respective bleaching regimes (B: 68.23 / 72.48; C: 68.32 / 73.25). Six months after starting the trial, L*-values for group B yielded no significant differences compared to baseline (69.55), whereas L*-values for group C were still significantly raised (69.91), despite a highly significant decrease when compared to initial bleaching results. In both treatment groups, there was a lasting response to bleaching in terms of CIE-a* and -b* value decreases. Results for both home- and in-practice regimes were found to be similar for about 12 weeks. However, in-office results were longer lasting, despite the shorter treatment intervals. Summarized bleaching effects, in terms of delta E values, revealed no significant differences between treatment groups and the control group after 6 months, indicating an abatement of the bleaching results achieved.

  6. Hydrogen peroxide in the western Mediterranean Sea: a tracer for vertical advection

    NASA Astrophysics Data System (ADS)

    Johnson, Kenneth S.; Willason, Stewart W.; Wiesenburg, Denis A.; Lohrenz, Steven E.; Arnone, Robert A.

    1989-02-01

    Hydrogen peroxide, micronutrients, chlorophyll, primary production and light were measured at a series of stations in the western Mediterranean Sea. Hydrogen peroxide concentrations greater than 100 nmol 1 -1 were found in this region. There was a significant relationship between hydrogen peroxide and primary production rates near the surface where the light intensity was high. This link between hydrogen peroxide and biological activity may have resulted from photochemically reactive organic compounds that were excreted during photosynthesis or from the direct biological production of hydrogen peroxide. Elevated concentrations were not found in the deep chlorophyll maximum however, which indicates that high light intensities are necessary for biogenic hydrogen peroxide production in this area. Hydrogen peroxide concentrations decreased much more slowly with depth than did light. The decoupling of light and hydrogen peroxide must have been due to a combination of a slow decay rate and rapid vertical transport. However, simple calculations indicate that eddy diffusion alone could not have transported enough hydrogen peroxide to produce the effects that were seen. Large anomalies in the concentration profiles that were detected in frontal regions indicate that hydrogen peroxide can be a useful tracer of vertical transport in the upper ocean. The size of the anomalies appears to be coupled to the salinity gradient across the front, which drives the frontal circulation.

  7. Photochemical formation of hydrogen peroxide in surface and ground waters exposed to sunlight

    SciTech Connect

    Cooper, W.J.; Zika, R.G.

    1983-05-13

    A rapid increase in the concentration of hydrogen peroxide was observed when samples of natural surface and ground water from various locations in the United States were exposed to sunlight. The hydrogen peroxide is photochemically generated from organic constitutents present in the water; humic materials are believed to be the primary agent producing the peroxide. Studies with superoxide dismutase suggest that the superoxide anion is the precursor of the peroxide.

  8. Vapor hydrogen peroxide as alternative to dry heat microbial reduction

    NASA Astrophysics Data System (ADS)

    Chung, S.; Kern, R.; Koukol, R.; Barengoltz, J.; Cash, H.

    2008-09-01

    The Jet Propulsion Laboratory (JPL), in conjunction with the NASA Planetary Protection Officer, has selected vapor phase hydrogen peroxide (VHP) sterilization process for continued development as a NASA approved sterilization technique for spacecraft subsystems and systems. The goal was to include this technique, with an appropriate specification, in NASA Procedural Requirements 8020.12 as a low-temperature complementary technique to the dry heat sterilization process. The VHP process is widely used by the medical industry to sterilize surgical instruments and biomedical devices, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal for this study was to determine the minimum VHP process conditions for planetary protection acceptable microbial reduction levels. Experiments were conducted by the STERIS Corporation, under contract to JPL, to evaluate the effectiveness of vapor hydrogen peroxide for the inactivation of the standard spore challenge, Geobacillus stearothermophilus. VHP process parameters were determined that provide significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters of interest: hydrogen peroxide concentration, number of injection cycles, and exposure duration, the investigation also considered the possible effect on lethality of environmental parameters: temperature, absolute humidity, and material substrate. This study delineated a range of test sterilizer process conditions: VHP concentration, process duration, a process temperature range for which the worst case D-value may be imposed, a process humidity range for which the worst case D-value may be imposed, and the dependence on selected spacecraft material substrates. The derivation of D-values from the lethality data permitted conservative planetary protection recommendations.

  9. Efficacy of hydrogen peroxide for treating saprolegniasis in channel catfish

    USGS Publications Warehouse

    Howe, G.E.; Gingerich, W.H.; Dawson, V.K.; Olson, J.J.

    1999-01-01

    Hatchery-reared fish and their eggs are commonly afflicted with saprolegniasis, a fungal disease that can cause significant losses in production. Fish culturists need safe and effective fungicides to minimize losses and meet production demands. The efficacy of hydrogen peroxide was evaluated for preventing or controlling mortality associated with saprolegniasis in channel catfish Ictalurus punctatus. Saprolegniasis was systematically induced in channel catfish so various therapies could be evaluated in a controlled laboratory environment. Both prophylactic and therapeutic hydrogen peroxide bath treatments of 50, 100, and 150 ??L/L for 1 h were administered every other day for seven total treatments. All untreated positive control fish died of saprolegniasis during the prophylactic and therapeutic tests. Hydrogen peroxide treatments of 150 ??L/L were harmful (relative to lower concentrations) to test fish and resulted in 73-95% mortality. Mortality was attributed to a combination of abrasion, temperature, chemical treatment, and disease stressors. Treatments of 100 ??L/L were less harmful (relatively) but also appeared to contribute to mortality (60-79%). These treatments, however, significantly reduced the incidence of mortality and infection compared with those observed for fish of the positive control or 150-??L/L treatment groups. Overall, treatments of 50 ??L/L were found to be the most safe and effective of those tested. Mortality with this concentration ranged from 16% in therapeutic tests to 41% in prophylactic tests. The statistical model employed estimated that the optimum treatment concentration for preventing or controlling mortality, reducing the incidence of infections, and enhancing the recovery of infected fish was 75 ??L H2O2/L.

  10. Hydrogen peroxide as an effective disinfectant for Pasteurella multocida.

    PubMed

    Jung, In-Soo; Kim, Hyun-Jung; Jung, Won-Yong; Kim, Chan-Wha

    2014-07-01

    Pasteurella multocida (P. multocida) infections vary widely, from local infections resulting from animal bites and scratches to general infections. As of yet, no vaccine against P. multocida has been developed, and the most effective way to prevent pathogenic transmission is to clean the host environment using disinfectants. In this study, we identified which disinfectants most effectively inhibited environmental isolates of P. multocida. Three readily available disinfectants were compared: 3% hydrogen peroxide (HP), 70% isopropyl alcohol, and synthetic phenol. In suspension tests and zone inhibition tests, 3% HP was the most promising disinfectant against P. multocida.

  11. Hydrogen peroxide in inflammation: messenger, guide, and assassin.

    PubMed

    Wittmann, C; Chockley, P; Singh, S K; Pase, L; Lieschke, G J; Grabher, C

    2012-01-01

    Starting as a model for developmental genetics, embryology, and organogenesis, the zebrafish has become increasingly popular as a model organism for numerous areas of biology and biomedicine over the last decades. Within haematology, this includes studies on blood cell development and function and the intricate regulatory mechanisms within vertebrate immunity. Here, we review recent studies on the immediate mechanisms mounting an inflammatory response by in vivo analyses using the zebrafish. These recently revealed novel roles of the reactive oxygen species hydrogen peroxide that have changed our view on the initiation of a granulocytic inflammatory response. PMID:22737171

  12. Detection of hydrogen peroxide by lactoperoxidase-mediated dityrosine formation.

    PubMed

    Donkó, Agnes; Orient, Anna; Szabó, Pál T; Németh, Gábor; Vántus, Tibor; Kéri, György; Orfi, László; Hunyady, László; Buday, László; Geiszt, Miklós

    2009-05-01

    The aim of this work was to study the dityrosine-forming activity of lactoperoxidase (LPO) and its potential application for measuring hydrogen peroxide (H2O2). It was observed that LPO was able to form dityrosine at low H2O2 concentrations. Since dityrosine concentration could be measured in a simple fluorimetric reaction, this activity of the enzyme was utilized for the measurement of H2O2 production in different systems. These experiments successfully measured the activity of NADPH oxidase 4 (Nox4) by this method. It was concluded that LPO-mediated dityrosine formation offers a simple way for H2O2 measurement.

  13. Hydrogen peroxide as a signal controlling plant programmed cell death

    PubMed Central

    Gechev, Tsanko S.; Hille, Jacques

    2005-01-01

    Hydrogen peroxide (H2O2) has established itself as a key player in stress and programmed cell death responses, but little is known about the signaling pathways leading from H2O2 to programmed cell death in plants. Recently, identification of key regulatory mutants and near-full genome coverage microarray analysis of H2O2-induced cell death have begun to unravel the complexity of the H2O2 network. This review also describes a novel link between H2O2 and sphingolipids, two signals that can interplay and regulate plant cell death. PMID:15631987

  14. Hydrogen peroxide-based propulsion and power systems.

    SciTech Connect

    Melof, Brian Matthew; Keese, David L.; Ingram, Brian V.; Grubelich, Mark Charles; Ruffner, Judith Alison; Escapule, William Rusty

    2004-04-01

    Less toxic, storable, hypergolic propellants are desired to replace nitrogen tetroxide (NTO) and hydrazine in certain applications. Hydrogen peroxide is a very attractive replacement oxidizer, but finding acceptable replacement fuels is more challenging. The focus of this investigation is to find fuels that have short hypergolic ignition delays, high specific impulse, and desirable storage properties. The resulting hypergolic fuel/oxidizer combination would be highly desirable for virtually any high energy-density applications such as small but powerful gas generating systems, attitude control motors, or main propulsion. These systems would be implemented on platforms ranging from guided bombs to replacement of environmentally unfriendly existing systems to manned space vehicles.

  15. The effect of hydrogen peroxide on polishing removal rate in CMP with various abrasives

    NASA Astrophysics Data System (ADS)

    Manivannan, R.; Ramanathan, S.

    2009-01-01

    The effect of hydrogen peroxide in chemical mechanical planarization slurries for shallow trench isolation was investigated. The various abrasives used in this study were ceria, silica, alumina, zirconia, titania, silicon carbide, and silicon nitride. Hydrogen peroxide suppresses the polishing of silicon dioxide and silicon nitride surfaces by ceria abrasives. The polishing performances of other abrasives were either unaffected or enhanced slightly with the addition of hydrogen peroxide. The ceria abrasives were treated with hydrogen peroxide, and the polishing of the work surfaces with the treated abrasive shows that the inhibiting action of hydrogen peroxide is reversible. It was found that the effect of hydrogen peroxide as an additive is a strong function of the nature of the abrasive particle.

  16. Revisiting the mesosome as a novel site of hydrogen peroxide accumulation in Escherichia coli.

    PubMed

    Xin, Li; Lipeng, Yang; Jiaju, Qiao; Hanqing, Feng; Yunhong, Liu; Min, Zhang; Yuxian, Zhang; Hongyu, Li

    2014-10-01

    The major source of endogenous hydrogen peroxide is generally thought to be the respiratory chain of bacteria and mitochondria. In our previous works, mesosome structure was induced in cells during rifampicin effect, and the mesosome formation is always accompanied by excess hydrogen peroxide accumulation in bacterial cells. However, the underlying mechanisms of hydrogen peroxide production and the rationale behind it remain still unknown. Here we report that hydrogen peroxide can specifically accumulate in the mesosome in vitro. Mesosomes were interpreted earlier as artifacts of specific cells under stress through TEM preparation, while, in the current study, mesosomes were shown as intracellular compartments with specific roles and features by using quickly freezing preparation of TEM. Formation of hydrogen peroxide was observed in suspension of mesosomal vesicles by using either a fluorescence-based reporter assay or a histochemical method, respectively. Our investigation provides experimental evidence that mesosomes can be a novel site of hydrogen peroxide accumulation.

  17. APPARATUS AND METHOD FOR TREATING POLLUTANTS IN A GAS USING HYDROGEN PEROXIDE AND UV LIGHT

    NASA Technical Reports Server (NTRS)

    Cooper, Charles David (Inventor); Clauseu, christian Anthony (Inventor)

    2005-01-01

    An apparatus for treating pollutants in a gas may include a source of hydrogen peroxide, and a treatment injector for creating and injecting dissociated hydrogen peroxide into the flow of gas. The treatment injector may further include an injector housing having an inlet, an outlet, and a hollow interior extending there between. The inlet may be connected in fluid communication with the source of hydrogen peroxide so that hydrogen peroxide flows through the hollow interior and toward the outlet. At least one ultraviolet (UV) lamp may be positioned within the hollow interior of the injector housing. The at least one UV lamp may dissociate the hydrogen peroxide flowing through the tube. The dissociated hydrogen peroxide may be injected into the flow of gas from the outlet for treating pollutants, such as nitrogen oxides.

  18. Apparatus and method for treating pollutants in a gas using hydrogen peroxide and UV light

    NASA Technical Reports Server (NTRS)

    Cooper, Charles David (Inventor); Clausen, Christian Anthony (Inventor)

    2005-01-01

    An apparatus for treating pollutants in a gas may include a source of hydrogen peroxide, and a treatment injector for creating and injecting dissociated hydrogen peroxide into the flow of gas. The treatment injector may further include an injector housing having an inlet, an outlet, and a hollow interior extending therebetween. The inlet may be connected in fluid communication with the source of hydrogen peroxide so that hydrogen peroxide flows through the hollow interior and toward the outlet. At least one ultraviolet (UV) lamp may be positioned within the hollow interior of the injector housing. The at least one UV lamp may dissociate the hydrogen peroxide flowing through the tube. The dissociated hydrogen peroxide may be injected into the flow of gas from the outlet for treating pollutants, such as nitrogen oxides.

  19. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    SciTech Connect

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-25

    Liquid natural rubber (LNR) with molecular weight of lower than 10{sup 5} and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA)

  20. Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

    NASA Astrophysics Data System (ADS)

    Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-01

    Liquid natural rubber (LNR) with molecular weight of lower than 105 and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA).

  1. Hydrogen Peroxide Accidents and Incidents: What We Can Learn From History

    NASA Technical Reports Server (NTRS)

    Greene, Ben; Baker, David L.; Frazier, Wayne

    2005-01-01

    Historical accidents and incidents involving hydrogen peroxide are reviewed and presented. These hydrogen peroxide events are associated with storage, transportation, handling, and disposal and they include exposures, fires, and explosions. Understanding the causes and effects of these accident and incident examples may aid personnel currently working with hydrogen peroxide to mitigate and perhaps avoid similar situations. Lessons learned, best practices, and regulatory compliance information related to the cited accidents and incidents are also discussed.

  2. Time-course diffusion of hydrogen peroxide using modern technologies

    NASA Astrophysics Data System (ADS)

    Florez, F. L. E.; Vollet-Filho, J. D.; Oliveira-Junior, O. B.; Bagnato, V. S.

    2009-02-01

    The concern with the hydrogen penetration towards the pulp can be observed on the literature by the great number of papers published on this topic; Those measurements often uses chemical agents to quantify the concentration of the bleaching agent that cross the enamel and dentin. The objective of this work was the quantification of oxygen free radicals by fluorescence that are located in the interface between enamel and dentin. It was used to accomplish our objectives a Ruthenium probe (FOXY R - Ocean Optics) a 405nm LED, a bovine tooth and a portable diagnostic system (Science and support LAB - LAT - IFSC/USP). The fluorescence of the probe is suppressed in presence of oxygen free radicals in function of time. The obtained results clearly shows that the hydrogen peroxide when not catalyzed should be kept in contact with the tooth for longer periods of time.

  3. Use of hydrogen peroxide as a biocide: new consideration of its mechanisms of biocidal action.

    PubMed

    Linley, Ezra; Denyer, Stephen P; McDonnell, Gerald; Simons, Claire; Maillard, Jean-Yves

    2012-07-01

    Hydrogen peroxide is extensively used as a biocide, particularly in applications where its decomposition into non-toxic by-products is important. Although increasing information on the biocidal efficacy of hydrogen peroxide is available, there is still little understanding of its biocidal mechanisms of action. This review aims to combine past and novel evidence of interactions between hydrogen peroxide and the microbial cell and its components, while reflecting on alternative applications that make use of gaseous hydrogen peroxide. It is currently believed that the Fenton reaction leading to the production of free hydroxyl radicals is the basis of hydrogen peroxide action and evidence exists for this reaction leading to oxidation of DNA, proteins and membrane lipids in vivo. Investigations of DNA oxidation suggest that the oxidizing radical is the ferryl radical formed from DNA-associated iron, not hydroxyl. Investigations of protein oxidation suggest that selective oxidation of certain proteins might occur, and that vapour-phase hydrogen peroxide is a more potent oxidizer of protein than liquid-phase hydrogen peroxide. Few studies have investigated membrane damage by hydrogen peroxide, though it is suggested that this is important for the biocidal mechanism. No studies have investigated damage to microbial cell components under conditions commonly used for sterilization. Despite extensive studies of hydrogen peroxide toxicity, the mechanism of its action as a biocide requires further investigation.

  4. Singlet oxygen generation from [bis(trifluoroacetoxy)iodo]benzene and hydrogen peroxide.

    PubMed

    Catir, Mustafa; Kilic, Hamdullah; Nardello-Rataj, Véronique; Aubry, Jean-Marie; Kazaz, Cavit

    2009-06-19

    Decomposition of hydrogen peroxide with a hypervalent iodine compound was examined. The results indicate that treatment of a hypervalent iodine compound with hydrogen peroxide produces singlet molecular oxygen ((1)O(2)). Convergent evidence for the production of singlet molecular oxygen ((1)O(2)) by decomposition of hydrogen peroxide with a hypervalent iodine compound comes from chemical trapping experiments and the specific chemiluminescence detection of (1)O(2) at 1270 nm. Substantial evidence demonstrates that hydroperoxyl radical produced from hydrogen peroxide with hypervalent iodine reacts via a tetraoxidane intermediate, decomposing to give singlet molecular oxygen. PMID:19449850

  5. Hydrogen peroxide generation from hydrated protein drink mixes.

    PubMed

    Boatright, William L

    2013-11-01

    Generation of oxygen radicals upon hydration of powdered protein products was examined using luminol-enhanced chemiluminescence. Among individual proteins powders examined oxidative bursts occurred almost immediately, and then rapidly declined in the 1st 5 min. Commercially available powdered protein drink mixes behaved differently, with an initial lag phase followed by a sustained increase in luminol-enhanced luminescence, lasting for an hour or beyond. The drink mix that produced the highest level of luminol-enhanced luminescence also contained 379 nM ascorbate radical when hydrated (28 nmole/g of powdered drink mix). The entire ascorbic acid content of this drink mix was oxidized to nondetectable levels (using HPLC-diode array detection) within 60 min of being hydrated. Treatment of the hydrated drink mixes with the enzyme catalase almost completely inhibited the luminol-enhanced luminescence from the hydrated drink mix demonstrating that hydrogen peroxide generated via a chemical reaction among the drink mixes' ingredients was a primary reactive oxygen species (ROS). This is the strongest oxidative capacity demonstrated in a food product as consumed (without any manipulation to increase ROS) and the 1st time that the ascrobate radical in a food product as been quantified. Generation of hydrogen peroxide in the hydrated drink mixes from metal catalyzed reactions involving oxygen and reducing equivalents from ascorbic acid is proposed.

  6. MEMS-based satellite micropropulsion via catalyzed hydrogen peroxide decomposition

    NASA Astrophysics Data System (ADS)

    Hitt, Darren L.; Zakrzwski, Charles M.; Thomas, Michael A.

    2001-12-01

    Microelectromechanical systems (MEMS) techniques offer great potential in satisfying the mission requirements for the next generation of miniaturized spacecraft being designed by NASA and Department of Defense agencies. More commonly referred to as `nanosats', these spacecraft feature masses in the range of 10-100 kg and therefore have unique propulsion requirements. The propulsion systems must be capable of providing extremely low levels of thrust and impulse while also satisfying stringent demands on size, mass, power consumption and cost. We begin with an overview of micropropulsion requirements and some current MEMS-based strategies being developed to meet these needs. The remainder of the paper focuses on the progress being made at NASA Goddard Space Flight Center toward the development of a prototype monopropellant MEMS thruster which uses the catalyzed chemical decomposition of high-concentration hydrogen peroxide as a propulsion mechanism. The products of decomposition are delivered to a microscale converging/diverging supersonic nozzle, which produces the thrust vector; the targeted thrust level is approximately 500 µN with a specific impulse of 140-180 s. Macroscale hydrogen peroxide thrusters have been used for satellite propulsion for decades; however, the implementation of traditional thruster designs on the MEMS scale has uncovered new challenges in fabrication, materials compatibility, and combustion and hydrodynamic modeling. A summary of the achievements of the project to date is given, as is a discussion of remaining challenges and future prospects.

  7. Fiber optic biosensors for hydrogen peroxide and L-lactate

    NASA Astrophysics Data System (ADS)

    Schubert, Florian; Rinneberg, Herbert H.; Wang, Fang

    1995-02-01

    An optical fiber biosensor for the selective determination of hydrogen peroxide has been developed as the base sensor for the construction of multienzyme optodes involving lactate converting enzymes for the analysis of lactic acid. The optode uses the H2O2 dependent oxidation of homovanillic acid by horseradish peroxidase (HRP) as the sensing reaction. The fluorescence of the dimeric product formed is used as the measuring signal related to the concentration of H2O2. HRP was immobilized on a membrane and combined with a bifurcated fiber optic probe. Under optimized conditions the sensor responds linearly to hydrogen peroxide between 1 micrometers ol/l and 0.12 mmol/l and exhibits a half life of 90 days. Using a lactate oxidase-HRP membrane, the sensor is suitable for lactate measurement with a linear range of 3 micrometers ol/l-0.2 mmol/l. To increase the sensitivity for lactate, lactate dehydrogenase was coimmobilized on the sensor membrane. In the presence of NADH the signal for lactate is amplified fourfold through the internal analyte recycling accomplished by the lactate-converting enzymes.

  8. MEMS-Based Satellite Micropropulsion Via Catalyzed Hydrogen Peroxide Decomposition

    NASA Technical Reports Server (NTRS)

    Hitt, Darren L.; Zakrzwski, Charles M.; Thomas, Michael A.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    Micro-electromechanical systems (MEMS) techniques offer great potential in satisfying the mission requirements for the next generation of "micro-scale" satellites being designed by NASA and Department of Defense agencies. More commonly referred to as "nanosats", these miniature satellites feature masses in the range of 10-100 kg and therefore have unique propulsion requirements. The propulsion systems must be capable of providing extremely low levels of thrust and impulse while also satisfying stringent demands on size, mass, power consumption and cost. We begin with an overview of micropropulsion requirements and some current MEMS-based strategies being developed to meet these needs. The remainder of the article focuses the progress being made at NASA Goddard Space Flight Center towards the development of a prototype monopropellant MEMS thruster which uses the catalyzed chemical decomposition of high concentration hydrogen peroxide as a propulsion mechanism. The products of decomposition are delivered to a micro-scale converging/diverging supersonic nozzle which produces the thrust vector; the targeted thrust level approximately 500 N with a specific impulse of 140-180 seconds. Macro-scale hydrogen peroxide thrusters have been used for satellite propulsion for decades; however, the implementation of traditional thruster designs on a MEMS scale has uncovered new challenges in fabrication, materials compatibility, and combustion and hydrodynamic modeling. A summary of the achievements of the project to date is given, as is a discussion of remaining challenges and future prospects.

  9. Vapor hydrogen peroxide as alternative to dry heat microbial reduction

    NASA Astrophysics Data System (ADS)

    Chung, S.; Kern, R.; Koukol, R.; Barengoltz, J.; Cash, H.

    The Jet Propulsion Laboratory in conjunction with the NASA Planetary Protection Officer has selected vapor phase hydrogen peroxide sterilization process for continued development as a NASA approved sterilization technique for spacecraft subsystems and systems The goal is to include this technique with appropriate specification in NPG8020 12C as a low temperature complementary technique to the dry heat sterilization process To meet microbial reduction requirements for all Mars in-situ life detection and sample return missions various planetary spacecraft subsystems will have to be exposed to a qualified sterilization process This process could be the elevated temperature dry heat sterilization process 115C for 40 hours which was used to sterilize the Viking lander spacecraft However with utilization of highly sophisticated electronics and sensors in modern spacecraft this process presents significant materials challenges and is thus undesirable to design engineers to achieve bioburden reduction The objective of this work is to introduce vapor hydrogen peroxide VHP as an alternative to dry heat microbial reduction to meet planetary protection requirements The VHP process is widely used by the medical industry to sterilize surgical instruments and biomedical devices but high doses of VHP may degrade the performance of flight hardware or compromise material compatibility Our goal for this study is to determine the minimum VHP process conditions for planetary protection acceptable microbial reduction levels A series of experiments were conducted to

  10. Hydrogen Peroxide and Sodium Transport in the Lung and Kidney.

    PubMed

    Shlyonsky, V; Boom, A; Mies, F

    2016-01-01

    Renal and lung epithelial cells are exposed to some significant concentrations of H2O2. In urine it may reach 100 μM, while in the epithelial lining fluid in the lung it is estimated to be in micromolar to tens-micromolar range. Hydrogen peroxide has a stimulatory action on the epithelial sodium channel (ENaC) single-channel activity. It also increases stability of the channel at the membrane and slows down the transcription of the ENaC subunits. The expression and the activity of the channel may be inhibited in some other, likely higher, oxidative states of the cell. This review discusses the role and the origin of H2O2 in the lung and kidney. Concentration-dependent effects of hydrogen peroxide on ENaC and the mechanisms of its action have been summarized. This review also describes outlooks for future investigations linking oxidative stress, epithelial sodium transport, and lung and kidney function. PMID:27073804

  11. Dissolution of ion exchange resin by hydrogen peroxide

    SciTech Connect

    Lee, S.C.

    1981-08-01

    The resin dissolution process was conducted successfully in full-scale equipment at the SRL Semiworks. A solution containing 0.001M Fe/sup 2 +/, or Fe/sup 3 +/, and 3 vol % H/sub 2/O/sub 2/ in 0.1M HNO/sub 3/ is sufficient to dissolve up to 40 vol % resin slurry (Dowex 50W-X8). Foaming and pressurization can be eliminated by maintaining the dissolution temperature below 99/sup 0/C. The recommended dissolution temperature range is 85 to 90/sup 0/C. Premixing hydrogen peroxide with all reactants will not create a safety hazard, but operating with a continual feed of hydrogen peroxide is recommended to control the dissolution rate. An air sparging rate of 1.0 to 1.5 scfm will provide sufficient mixing. Spent resin from chemical separation contains DTPA (diethylenetriaminepentaacetic acid) residue, and the resin must be washed with 0.1M NH/sub 4/ OH to remove excess DTPA before dissolution. Gamma irradiation of resin up to 4 kW-hr/L did not change the dissolution rate significantly.

  12. Antifungal efficacy of hydrogen peroxide in dental unit waterline disinfection.

    PubMed

    Szymańska, Jolanta

    2006-01-01

    The concentration and composition of fungal flora in dental unit waterlines (DUWL) were evaluated. For this purpose, water samples from unit reservoirs and high-speed handpieces, and biofilm samples from the waterline walls from units were collected. Subsequently, analogous samples from DUWL were taken before and after disinfection using agent containing hydrogen peroxide. In the examined samples, the yeast-like fungi Candida albicans and Candida curvata were found. The following species of mould were also identified: Aspergillus amstelodami, Aspergillus fumigatus, Aspergillus glaucus group, Aspergillus (=Eurotium herbariorum) repens, Citromyces spp., Geotrichum candidum, Penicillium (glabrum) frequentans, Penicillium pusillum, Penicillium turolense and Sclerotium sclerotiorum (Sclerotinia sclerotiorum). Before disinfection, Candida curvata and Candida albicans constituted the greatest proportion of the total fungi in the reservoirs water; in the water of handpieces--Candida albicans and Aspergillus glaucus group; and in the biofilm samples--Aspergillus glaucus group and Candida albicans. After disinfection, in all 3 kinds of samples, Candida albicans prevailed, constituting from 31.2-85.7 % of the total fungi. The application of agent containing hydrogen peroxide caused a significant decrease both in the number of total fungi and individual fungal species, which confirms the product effectiveness in fungal decontamination of DUWL. PMID:17196007

  13. Radiographic findings following irrigation of chronic perineal drain with hydrogen peroxide

    PubMed Central

    Melin, Alyson A.; Heckman, Andrew M.; Hussain, Shahid; Thompson, Jon S.

    2014-01-01

    INTRODUCTION Hydrogen peroxide is a widely available agent used for irrigation and disinfecting. With misuse, significant side effects have been noted ranging from nausea to abdominal cramping to portal venous gas, air embolism and death. PRESENTATION OF CASE We present an 81 year old male who developed a rectovesicular fistula following radiation for metastatic prostate cancer. He had recurrent bleeding and infections and underwent a pelvic exenteration which was complicated by a persistent pelvic abscess requiring placement of a transperineal drainage catheter. After months of persistent drainage, he noted decreased output and irrigated the catheter with 3% hydrogen peroxide. He presented to the emergency room with fever, diarrhea and abdominal cramping but no rebound or guarding. CT depicted free air in the pre-sacral space extending into the retroperitoneum and diffusely throughout the peritoneum. Given his clinical exam and upon review of imaging, we assumed his radiographic findings were related to the direct instillation of hydrogen peroxide into his chronic pelvic cavity. DISCUSSION Hydrogen peroxide has been used therapeutically for over 100 years. Hydrogen peroxide exerts direct cytotoxicity by corrosion and lipid peroxidation and indirectly by oxygen gas formation. When the oxygen produced exceeds the solubility in the blood, arterial and venous gas embolism occur. It is this sequelae of hydrogen peroxide that is described most frequently in the literature. CONCLUSION Instillation of hydrogen peroxide into a chronic pelvic cavity resulted in a benign pneumoperitoneum. This effect of hydrogen peroxide is a significant and potentially treatment altering radiographic finding. PMID:25560055

  14. Effect of species, life stage, and water temperature on the toxicity of hydrogen peroxide to fish

    USGS Publications Warehouse

    Rach, J.J.; Schreier, T.M.; Howe, G.E.; Redman, S.D.

    1997-01-01

    Hydrogen peroxide is a drug of low regulatory priority status that is effective in treating fish and fish eggs infected by fungi. However, only limited information is available to guide fish culturists in administering hydrogen peroxide to diseased fish. Laboratory tests were conducted to determine (1) the sensitivity of brown trout Salmo trutta, lake trout Salvelinus namaycush, fathead minnow Pimephales promelas, walleye Stizostedion vitreum, channel catfish Ictalurus punctatus, and bluegill Lepomis, machrochirus to hydrogen peroxide treatments; (2) the sensitivity of various life stages of rainbow trout Oncorhynchus mykiss to hydrogen peroxide treatments; and (3) the effect of water temperature on the acute toxicity of hydrogen peroxide to three fish species. Fish were exposed to hydrogen peroxide concentrations ranging from 100 to 5,000 mu L/L (ppm) for 15-min or 45-min treatments every other day for four consecutive treatments to determine the sensitivity of various species and life stages of fish. Except for walleye, most species of fish tested (less than or equal to 2 g) tolerated hydrogen peroxide of 1,000 mu L/L or greater. Walleyes were sensitive to hydrogen peroxide concentrations as low as 100 mu L/L. A correlation was found between the toxicity of hydrogen peroxide and the life stages of rainbow trout; larger fish were more sensitive. Generally, the toxicity of hydrogen peroxide increased for all species as water temperature increased. The results of these experiments demonstrate that it is important to consider the effects of species, life stage, and water temperature when conducting hydrogen peroxide treatments.

  15. Photoluminescence of MoS2 quantum dots quenched by hydrogen peroxide: A fluorescent sensor for hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Gan, Zhixing; Gui, Qingfeng; Shan, Yun; Pan, Pengfei; Zhang, Ning; Zhang, Lifa

    2016-09-01

    By cutting MoS2 microcrystals to quantum dots (QDs) of sizes below 10 nm, the photoluminescence (PL) at ca. 450 nm can be detected easily due to the quantum confinement effects across the 2D planes. The PL is stable under continuous irradiation of UV light but gradually quenches when treated with an increasing concentration of hydrogen peroxide. Time-resolved PL and Raman spectra imply that H2O2 causes the partial oxidation of MoS2 QDs. First-principles calculations reveal that the MoS2 QDs with oxygen impurity are of indirect bandgap structures showing no notable PL. And absorption spectra verify that the PL of MoS2 QDs quenched by H2O2 is attributed to the oxidation. The integrated PL intensity and H2O2 concentration show an exponential relationship in the range of 2-20 μM, suggesting that MoS2 QDs are potential fluorescent probes for hydrogen peroxide sensing in a physiological environment.

  16. [Acute ischemia of the hand, an unknown complication of the hydrogen peroxide irrigation. Case report].

    PubMed

    Zemirline, A; Loaëc, F; Hélaine, L; Richou, J; Le Nen, D

    2011-04-01

    We report a case of acute transitional ischemia of the hand with acute compartment syndrome of the forearm, following hydrogen peroxide irrigation of a wound. We discuss the physiopathology and management of this complication. Along with numerous related cases of gas embolism, this complication emphasizes the risks of using hydrogen peroxide under pressure, notably in hand surgery.

  17. Role of hydrogen peroxide and hydroxyl radical in pyrite oxidation by molecular oxygen

    NASA Astrophysics Data System (ADS)

    Schoonen, Martin A. A.; Harrington, Andrea D.; Laffers, Richard; Strongin, Daniel R.

    2010-09-01

    Hydrogen peroxide and hydroxyl radical are readily formed during the oxidation of pyrite with molecular oxygen over a wide range of pH conditions. However, pretreatment of the pyrite surface influences how much of the intermediates are formed and their fate. Acid-washed pyrite produces significant amounts of hydrogen peroxide and hydroxyl radical when suspended in air-saturated water. However, the hydrogen peroxide concentration shows an exponential decrease with time. Suspensions made with partially oxidized pyrite yield significantly lower amounts of hydrogen peroxide product. The presence of Fe(III)-oxide or Fe(III)-hydroxide patches facilitates the conversion of hydrogen peroxide to oxygen and water. Hence, the degree to which a pyrite surface is covered with patches of Fe(III)-oxide or Fe(III)-hydroxide patches is an important control on the concentration of hydrogen peroxide in solution. Hydrogen peroxide appears to be an important intermediate in the four-electron transfer from pyrite to molecular oxygen. Addition of catalase, an enzyme that decomposes hydrogen peroxide to water and molecular oxygen, to a pyrite suspension reduces the oxidation rate by 40%. By contrast, hydroxyl radical does not appear to play a significant role in the oxidation mechanism. It is estimated on the basis of a molecular oxygen and sulfate mass balance that 5-6% of the molecular oxygen is consumed without forming sulfate.

  18. Hydrogen peroxide and povidone-lodine solution--a dangerous combination.

    PubMed

    2011-02-01

    When mixed with povidone-iodine solution, hydrogen peroxide can release enough oxygen to cause sealed waste containers to burst open. Such risks can also result from using a sealed container to collect hydrogen peroxide that has mixed with body fluids (for instance, in a debridement procedure). Staff should be instructed to avoid both practices. PMID:23444560

  19. An Experimental Investigation of Hypergolic Ignition Delay of Hydrogen Peroxide with Fuel Mixtures

    NASA Technical Reports Server (NTRS)

    Blevins, John A.; Gostowski, Rudy; Chianese, Silvio

    2003-01-01

    An experimental evaluation of decomposition and ignition delay of hydrogen peroxide at concentrations of 80% to 98% with combinations of hydrocarbon fuels, tertiary amines and transition metal chelates will be presented in the proposed paper. The results will be compared to hydrazine ignition delays with hydrogen peroxide and nitric acid mixtures using the same test apparatus.

  20. Oxygen from Hydrogen Peroxide. A Safe Molar Volume-Molar Mass Experiment.

    ERIC Educational Resources Information Center

    Bedenbaugh, John H.; And Others

    1988-01-01

    Describes a molar volume-molar mass experiment for use in general chemistry laboratories. Gives background technical information, procedures for the titration of aqueous hydrogen peroxide with standard potassium permanganate and catalytic decomposition of hydrogen peroxide to produce oxygen, and a discussion of the results obtained in three…

  1. Development of vapor phase hydrogen peroxide sterilization process for spacecraft applications

    NASA Technical Reports Server (NTRS)

    Rohatgi, N.; Schubert, W.; Knight, J.; Quigley, M.; Forsberg, G.; Ganapathi, G.; Yarbrough, C.; Koukol, R.

    2001-01-01

    This paper will present test data and discussion on the work we are conducting at JPL to address the following issues: 1) efficacy of sterilization process; 2) diffusion of hydrogen peroxide under sterilization process conditions into hard to reach places; 3) materials and components compatibility with the sterilization process and 4) development of methodology to protect sensitive components from hydrogen peroxide vapor.

  2. Efficacy of Mouthwashes Containing Hydrogen Peroxide on Tooth Whitening.

    PubMed

    Karadas, Muhammet; Hatipoglu, Omer

    2015-01-01

    The aim of this study was to analyze the efficacy of mouthwashes containing hydrogen peroxide compared with 10% carbamide peroxide (CP) gel. Fifty enamel-dentin samples were obtained from bovine incisors and then stained in a tea solution. The stained samples were randomly divided into five groups according to the whitening product applied (n = 10): AS: no whitening (negative control), with the samples stored in artificial saliva; CR: Crest 3D White mouthwash; LS: Listerine Whitening mouthwash; SC: Scope White mouthwash; and OP group: 10% CP Opalescence PF (positive control). Color measurements were carried out with a spectrophotometer before staining, after staining, and on the 7th, 28th, and 56th day of the whitening period. The data were analyzed using two-way analysis of variance followed by a Tukey post hoc test. The color change (ΔE) was significantly greater in all the groups compared to that of the AS group. After 56 days, no significant differences were found among the mouthwash products with respect to color change (P > 0.05). The whiteness of the teeth treated with the mouthwashes increased significantly over time. Nevertheless, the color change achieved with the mouthwashes was significantly lower than that achieved with the 10% CP at-home bleaching gel.

  3. Efficacy of Mouthwashes Containing Hydrogen Peroxide on Tooth Whitening

    PubMed Central

    Karadas, Muhammet; Hatipoglu, Omer

    2015-01-01

    The aim of this study was to analyze the efficacy of mouthwashes containing hydrogen peroxide compared with 10% carbamide peroxide (CP) gel. Fifty enamel-dentin samples were obtained from bovine incisors and then stained in a tea solution. The stained samples were randomly divided into five groups according to the whitening product applied (n = 10): AS: no whitening (negative control), with the samples stored in artificial saliva; CR: Crest 3D White mouthwash; LS: Listerine Whitening mouthwash; SC: Scope White mouthwash; and OP group: 10% CP Opalescence PF (positive control). Color measurements were carried out with a spectrophotometer before staining, after staining, and on the 7th, 28th, and 56th day of the whitening period. The data were analyzed using two-way analysis of variance followed by a Tukey post hoc test. The color change (ΔE) was significantly greater in all the groups compared to that of the AS group. After 56 days, no significant differences were found among the mouthwash products with respect to color change (P > 0.05). The whiteness of the teeth treated with the mouthwashes increased significantly over time. Nevertheless, the color change achieved with the mouthwashes was significantly lower than that achieved with the 10% CP at-home bleaching gel. PMID:26295061

  4. Efficacy of Mouthwashes Containing Hydrogen Peroxide on Tooth Whitening.

    PubMed

    Karadas, Muhammet; Hatipoglu, Omer

    2015-01-01

    The aim of this study was to analyze the efficacy of mouthwashes containing hydrogen peroxide compared with 10% carbamide peroxide (CP) gel. Fifty enamel-dentin samples were obtained from bovine incisors and then stained in a tea solution. The stained samples were randomly divided into five groups according to the whitening product applied (n = 10): AS: no whitening (negative control), with the samples stored in artificial saliva; CR: Crest 3D White mouthwash; LS: Listerine Whitening mouthwash; SC: Scope White mouthwash; and OP group: 10% CP Opalescence PF (positive control). Color measurements were carried out with a spectrophotometer before staining, after staining, and on the 7th, 28th, and 56th day of the whitening period. The data were analyzed using two-way analysis of variance followed by a Tukey post hoc test. The color change (ΔE) was significantly greater in all the groups compared to that of the AS group. After 56 days, no significant differences were found among the mouthwash products with respect to color change (P > 0.05). The whiteness of the teeth treated with the mouthwashes increased significantly over time. Nevertheless, the color change achieved with the mouthwashes was significantly lower than that achieved with the 10% CP at-home bleaching gel. PMID:26295061

  5. Kinetics of hydrogen peroxide decomposition by catalase: hydroxylic solvent effects.

    PubMed

    Raducan, Adina; Cantemir, Anca Ruxandra; Puiu, Mihaela; Oancea, Dumitru

    2012-11-01

    The effect of water-alcohol (methanol, ethanol, propan-1-ol, propan-2-ol, ethane-1,2-diol and propane-1,2,3-triol) binary mixtures on the kinetics of hydrogen peroxide decomposition in the presence of bovine liver catalase is investigated. In all solvents, the activity of catalase is smaller than in water. The results are discussed on the basis of a simple kinetic model. The kinetic constants for product formation through enzyme-substrate complex decomposition and for inactivation of catalase are estimated. The organic solvents are characterized by several physical properties: dielectric constant (D), hydrophobicity (log P), concentration of hydroxyl groups ([OH]), polarizability (α), Kamlet-Taft parameter (β) and Kosower parameter (Z). The relationships between the initial rate, kinetic constants and medium properties are analyzed by linear and multiple linear regression.

  6. Hydrogen peroxide as an endothelium-derived hyperpolarizing factor.

    PubMed

    Shimokawa, Hiroaki; Matoba, Tetsuya

    2004-06-01

    Vascular endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several vasodilating factors, such as prostacyclin, nitric oxide (NO), and a yet unidentified endothelium-derived hyperpolarizing factor (EDHF). Possible candidates for EDHF include epoxyeicosatrienoic acids (EETs), endothelium-derived potassium ions (K(+)), and as we have recently identified, hydrogen peroxide (H2O2). Electrical communication between endothelial and smooth muscle cells through gap junctions has also been suggested to be involved in endothelium-dependent hyperpolarization. Among the above candidates, the H2O2 hypothesis well explains the pathophysiological interactions between NO and EDHF and re-highlights the physiological roles of the reactive oxygen species (ROS) in endothelium-dependent vascular responses. This brief review summarizes our current knowledge about H2O2 as an EDHF, with special reference to its production by the endothelium, its action on membrane potentials and its pathophysiological roles. PMID:15026032

  7. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1988-01-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  8. Vapor Hydrogen Peroxide as Alternative to Dry Heat Microbial Reduction

    NASA Technical Reports Server (NTRS)

    Cash, Howard A.; Kern, Roger G.; Chung, Shirley Y.; Koukol, Robert C.; Barengoltz, Jack B.

    2006-01-01

    The Jet Propulsion Laboratory, in conjunction with the NASA Planetary Protection Officer, has selected vapor phase hydrogen peroxide (VHP) sterilization process for continued development as a NASA approved sterilization technique for spacecraft subsystems and systems. The goal is to include this technique, with appropriate specification, in NPG8020.12C as a low temperature complementary technique to the dry heat sterilization process. A series of experiments were conducted in vacuum to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. With this knowledge of D values, sensible margins can be applied in a planetary protection specification. The outcome of this study provided an optimization of test sterilizer process conditions: VHP concentration, process duration, a process temperature range for which the worst case D value may be imposed, a process humidity range for which the worst case D value may be imposed, and robustness to selected spacecraft material substrates.

  9. Plasma Depolymerization of Chitosan in the Presence of Hydrogen Peroxide

    PubMed Central

    Ma, Fengming; Wang, Zhenyu; Zhao, Haitian; Tian, Shuangqi

    2012-01-01

    The depolymerization of chitosan by plasma in the presence of hydrogen peroxide (H2O2) was investigated. The efficiency of the depolymerization was demonstrated by means of determination of viscosity-average molecular weight and gel permeation chromatography (GPC). The structure of the depolymerized chitosan was characterized by Fourier-transform infrared spectra (FT-IR), ultraviolet spectra (UV) and X-ray diffraction (XRD). The results showed that chitosan can be effectively degradated by plasma in the presence of H2O2. The chemical structure of the depolymerized chitosan was not obviously modified. The combined plasma/H2O2 method is significantly efficient for scale-up manufacturing of low molecular weight chitosan. PMID:22837727

  10. Kinetics of hydrogen peroxide decomposition by catalase: hydroxylic solvent effects.

    PubMed

    Raducan, Adina; Cantemir, Anca Ruxandra; Puiu, Mihaela; Oancea, Dumitru

    2012-11-01

    The effect of water-alcohol (methanol, ethanol, propan-1-ol, propan-2-ol, ethane-1,2-diol and propane-1,2,3-triol) binary mixtures on the kinetics of hydrogen peroxide decomposition in the presence of bovine liver catalase is investigated. In all solvents, the activity of catalase is smaller than in water. The results are discussed on the basis of a simple kinetic model. The kinetic constants for product formation through enzyme-substrate complex decomposition and for inactivation of catalase are estimated. The organic solvents are characterized by several physical properties: dielectric constant (D), hydrophobicity (log P), concentration of hydroxyl groups ([OH]), polarizability (α), Kamlet-Taft parameter (β) and Kosower parameter (Z). The relationships between the initial rate, kinetic constants and medium properties are analyzed by linear and multiple linear regression. PMID:22565543

  11. What is the role of hydrogen peroxide in plant peroxisomes?

    PubMed

    Corpas, Francisco J

    2015-11-01

    Plant peroxisomes are unusual subcellular compartments with an apparent simple morphology but with complex metabolic activity. The presence of signal molecules, such as hydrogen peroxide (H(2)O(2)) and nitric oxide inside plant peroxisomes have added new functions in the cross-talk events among organelles and cells under physiological and stress conditions. Moreover, recent advances in proteomic analyses of plant peroxisomes have identified new protein candidates involved in several novel metabolic pathways. With all these new data, the present concise manuscript will focus on the relevance of the peroxisomal H(2)O(2) and its two main antioxidant enzymes, catalase and membrane-bound ascorbate peroxidase, which regulate its level and consequently its potential functions.

  12. Greywater disinfection with the environmentally friendly Hydrogen Peroxide Plus (HPP).

    PubMed

    Ronen, Zeev; Guerrero, Adriana; Gross, Amit

    2010-01-01

    Hydrogen Peroxide Plus (HPP) is a newly developed, stabilized-H(2)O(2)-based compound. This study was aimed at determining the disinfection efficiency of HPP in greywater (GW), assessing HPP dose requirements and evaluating the feasibility of its use in small-scale GW-treatment systems. Fecal coliforms were the most sensitive to treatment, followed by somatic coliphages and F+ bacteriophages. The calculated HPP dose required to reduce fecal coliform counts by 99% was 125mg H(2)O(2)L(-1), with a contact time of 35min. The use of HPP was found feasible and comparable to the use of chlorine for small systems with a flow rate of 5m(3)d(-1). HPP is suggested as an alternative for GW disinfection in small communities and private houses.

  13. Alkaline hydrogen peroxide pretreatment of softwood: hemicellulose degradation pathways.

    PubMed

    Alvarez-Vasco, Carlos; Zhang, Xiao

    2013-12-01

    This study investigated softwood hemicelluloses degradation pathways during alkaline hydrogen peroxide (AHP) pretreatment of Douglas fir. It was found that glucomannan is much more susceptible to alkaline pretreatment than xylan. Organic acids, including lactic, succinic, glycolic and formic acid are the predominant products from glucomannan degradation. At low treatment temperature (90°C), a small amount of formic acid is produced from glucomannan, whereas glucomannan degradation to lactic acid and succinic acid becomes the main reactions at 140°C and 180°C. The addition of H2O2 during alkaline pretreatment of D. fir led to a significant removal of lignin, which subsequently facilitated glucomannan solubilization. However, H2O2 has little direct effect on the glucomannan degradation reaction. The main degradation pathways involved in glucomannan conversion to organics acids are elucidated. The results from this study demonstrate the potential to optimize pretreatment conditions to maximize the value of biomass hemicellulose.

  14. Pd nanoparticle-modified electrodes for nonenzymatic hydrogen peroxide detection

    NASA Astrophysics Data System (ADS)

    Wang, Jue; Chen, Xue-jiao; Liao, Kai-ming; Wang, Guang-hou; Han, Min

    2015-08-01

    A hydrogen peroxide (H2O2) sensor based on Pd nanoparticles (NPs) and glassy carbon electrodes (GCEs) is fabricated. Pd NPs are deposited on GCEs by using a gas phase cluster beam deposition technique. The NP-deposited electrodes show enhanced electrocatalytic activity in reduction of H2O2. The electrode with an optimized NP coverage of 85 % has a high selective and stable nonenzymatic sensing ability of H2O2 with a low detection limit (3.4 × 10-7 M), high sensitivity (50.9 μA mM-1), and a wide linear range (from 1.0 × 10-6 to 6.0 × 10-3 M). The reduction peak potential of the electrode is close to -0.12 V, which enables high selective amperometric detection of H2O2 at a low applied potential.

  15. Development of hydrogen peroxide technique for bioburden reduction

    NASA Astrophysics Data System (ADS)

    Rohatgi, N.; Schwartz, L.; Stabekis, P.; Barengoltz, J.

    In order to meet the National Aeronautics and Space Administration (NASA) Planetary Protection microbial reduction requirements for Mars in-situ life detection and sample return missions, entire planetary spacecraft (including planetary entry probes and planetary landing capsules) may have to be exposed to a qualified sterilization process. Presently, dry heat is the only NASA approved sterilization technique available for spacecraft application. However, with the increasing use of various man-made materials, highly sophisticated electronic circuit boards, and sensors in a modern spacecraft, compatibility issues may render this process unacceptable to design engineers and thus impractical to achieve terminal sterilization of the entire spacecraft. An alternative vapor phase hydrogen peroxide sterilization process, which is currently used in various industries, has been selected for further development. Strategic Technology Enterprises, Incorporated (STE), a subsidiary of STERIS Corporation, under a contract from the Jet Propulsion Laboratory (JPL) is developing systems and methodologies to decontaminate spacecraft using vaporized hydrogen peroxide (VHP) technology. The VHP technology provides an effective, rapid and low temperature means for inactivation of spores, mycobacteria, fungi, viruses and other microorganisms. The VHP application is a dry process affording excellent material compatibility with many of the components found in spacecraft such as polymers, paints and electronic systems. Furthermore, the VHP process has innocuous residuals as it decomposes to water vapor and oxygen. This paper will discuss the approach that is being used to develop this technique and will present lethality data that have been collected to establish deep vacuum VHP sterilization cycles. In addition, the application of this technique to meet planetary protection requirements will be addressed.

  16. Hydrogen Peroxide, Signaling in Disguise during Metal Phytotoxicity

    PubMed Central

    Cuypers, Ann; Hendrix, Sophie; Amaral dos Reis, Rafaela; De Smet, Stefanie; Deckers, Jana; Gielen, Heidi; Jozefczak, Marijke; Loix, Christophe; Vercampt, Hanne; Vangronsveld, Jaco; Keunen, Els

    2016-01-01

    Plants exposed to excess metals are challenged by an increased generation of reactive oxygen species (ROS) such as superoxide (O2•-), hydrogen peroxide (H2O2) and the hydroxyl radical (•OH). The mechanisms underlying this oxidative challenge are often dependent on metal-specific properties and might play a role in stress perception, signaling and acclimation. Although ROS were initially considered as toxic compounds causing damage to various cellular structures, their role as signaling molecules became a topic of intense research over the last decade. Hydrogen peroxide in particular is important in signaling because of its relatively low toxicity, long lifespan and its ability to cross cellular membranes. The delicate balance between its production and scavenging by a plethora of enzymatic and metabolic antioxidants is crucial in the onset of diverse signaling cascades that finally lead to plant acclimation to metal stress. In this review, our current knowledge on the dual role of ROS in metal-exposed plants is presented. Evidence for a relationship between H2O2 and plant metal tolerance is provided. Furthermore, emphasis is put on recent advances in understanding cellular damage and downstream signaling responses as a result of metal-induced H2O2 production. Finally, special attention is paid to the interaction between H2O2 and other signaling components such as transcription factors, mitogen-activated protein kinases, phytohormones and regulating systems (e.g. microRNAs). These responses potentially underlie metal-induced senescence in plants. Elucidating the signaling network activated during metal stress is a pivotal step to make progress in applied technologies like phytoremediation of polluted soils. PMID:27199999

  17. Chemiluminescent Nanomicelles for Imaging Hydrogen Peroxide and Self-Therapy in Photodynamic Therapy

    PubMed Central

    Chen, Rui; Zhang, Luzhong; Gao, Jian; Wu, Wei; Hu, Yong; Jiang, Xiqun

    2011-01-01

    Hydrogen peroxide is a signal molecule of the tumor, and its overproduction makes a higher concentration in tumor tissue compared to normal tissue. Based on the fact that peroxalates can make chemiluminescence with a high efficiency in the presence of hydrogen peroxide, we developed nanomicelles composed of peroxalate ester oligomers and fluorescent dyes, called peroxalate nanomicelles (POMs), which could image hydrogen peroxide with high sensitivity and stability. The potential application of the POMs in photodynamic therapy (PDT) for cancer was also investigated. It was found that the PDT-drug-loaded POMs were sensitive to hydrogen peroxide, and the PDT drug could be stimulated by the chemiluminescence from the reaction between POMs and hydrogen peroxide, which carried on a self-therapy of the tumor without the additional laser light resource. PMID:21765637

  18. Inactivation of possible micromycete food contaminants using the low-temperature plasma and hydrogen peroxide

    SciTech Connect

    Čeřovský, M.; Khun, J.; Rusová, K.; Scholtz, V.; Soušková, H.

    2013-09-15

    The inhibition effect of hydrogen peroxide aerosol, low-temperature plasma and their combinations has been studied on several micromycetes spores. The low-temperature plasma was generated in corona discharges in the open air apparatus with hydrogen peroxide aerosol. Micromycete spores were inoculated on the surface of agar plates, exposed solely to the hydrogen peroxide aerosol, corona discharge or their combination. After incubation the diameter of inhibition zone was measured. The solely positive corona discharge exhibits no inactivation effect, the solely negative corona discharge and solely hydrogen peroxide aerosol exhibit the inactivation effect, however their combinations exhibit to be much more effective. Low-temperature plasma and hydrogen peroxide aerosol present a possible alternative method of microbial decontamination of food, food packages or other thermolabile materials.

  19. Spatially-resolved intracellular sensing of hydrogen peroxide in living cells.

    PubMed

    Warren, Emilie A K; Netterfield, Tatiana S; Sarkar, Saheli; Kemp, Melissa L; Payne, Christine K

    2015-11-20

    Understanding intracellular redox chemistry requires new tools for the site-specific visualization of intracellular oxidation. We have developed a spatially-resolved intracellular sensor of hydrogen peroxide, HyPer-Tau, for time-resolved imaging in live cells. This sensor consists of a hydrogen peroxide-sensing protein tethered to microtubules. We demonstrate the use of the HyPer-Tau sensor for three applications; dose-dependent response of human cells to exogenous hydrogen peroxide, a model immune response of mouse macrophages to stimulation by bacterial toxin, and a spatially-resolved response to localized delivery of hydrogen peroxide. These results demonstrate that HyPer-Tau can be used as an effective tool for tracking changes in spatially localized intracellular hydrogen peroxide and for future applications in redox signaling.

  20. Overoxidation of chloroplast 2-Cys peroxiredoxins: balancing toxic and signaling activities of hydrogen peroxide

    PubMed Central

    Puerto-Galán, Leonor; Pérez-Ruiz, Juan M.; Ferrández, Julia; Cano, Beatriz; Naranjo, Belén; Nájera, Victoria A.; González, Maricruz; Lindahl, Anna M.; Cejudo, Francisco J.

    2013-01-01

    Photosynthesis, the primary source of biomass and oxygen into the biosphere, involves the transport of electrons in the presence of oxygen and, therefore, chloroplasts constitute an important source of reactive oxygen species, including hydrogen peroxide. If accumulated at high level, hydrogen peroxide may exert a toxic effect; however, it is as well an important second messenger. In order to balance the toxic and signaling activities of hydrogen peroxide its level has to be tightly controlled. To this end, chloroplasts are equipped with different antioxidant systems such as 2-Cys peroxiredoxins (2-Cys Prxs), thiol-based peroxidases able to reduce hydrogen and organic peroxides. At high peroxide concentrations the peroxidase function of 2-Cys Prxs may become inactivated through a process of overoxidation. This inactivation has been proposed to explain the signaling function of hydrogen peroxide in eukaryotes, whereas in prokaryotes, the 2-Cys Prxs of which were considered to be insensitive to overoxidation, the signaling activity of hydrogen peroxide is less relevant. Here we discuss the current knowledge about the mechanisms controlling 2-Cys Prx overoxidation in chloroplasts, organelles with an important signaling function in plants. Given the prokaryotic origin of chloroplasts, we discuss the occurrence of 2-Cys Prx overoxidation in cyanobacteria with the aim of identifying similarities between chloroplasts and their ancestors regarding their response to hydrogen peroxide. PMID:23967002

  1. Measurement of hydrogen peroxide in an advanced oxidation process using an automated biosensor.

    PubMed

    Modrzejewska, B; Guwy, A J; Dinsdale, R; Hawkes, D L

    2007-01-01

    A hydrogen peroxide biosensor was used to monitor hydrogen peroxide concentrations in a UV/hydrogen peroxide immobilised Fenton advanced oxidation process (AOP). The biosensor is based on gas phase monitoring and thus is more resistant to fouling from the liquid phase constituents of industrial processes. The biosensor is supplied with catalase continually, therefore overcoming any problems with enzyme degradation, which would occur in an immobilised enzyme biosensor. The biosensors response was linear within the experimental range 30-400mg H(2)O(2)l(-1) with a R(2) correlation of 0.99. The hydrogen peroxide monitor was used to monitor residual peroxide in an AOP, operated with a step overload of hydrogen peroxide, with correlation factors of 0.96-0.99 compared to offline hydrogen peroxide determinations by UV spectroscopy. Sparging the sample with nitrogen was found to be effective in reducing the interference from dissolved gases produced with the AOP itself. It is proposed that this biosensor could be used to improve the effectiveness of AOPs via hydrogen peroxide control.

  2. Overoxidation of chloroplast 2-Cys peroxiredoxins: balancing toxic and signaling activities of hydrogen peroxide.

    PubMed

    Puerto-Galán, Leonor; Pérez-Ruiz, Juan M; Ferrández, Julia; Cano, Beatriz; Naranjo, Belén; Nájera, Victoria A; González, Maricruz; Lindahl, Anna M; Cejudo, Francisco J

    2013-01-01

    Photosynthesis, the primary source of biomass and oxygen into the biosphere, involves the transport of electrons in the presence of oxygen and, therefore, chloroplasts constitute an important source of reactive oxygen species, including hydrogen peroxide. If accumulated at high level, hydrogen peroxide may exert a toxic effect; however, it is as well an important second messenger. In order to balance the toxic and signaling activities of hydrogen peroxide its level has to be tightly controlled. To this end, chloroplasts are equipped with different antioxidant systems such as 2-Cys peroxiredoxins (2-Cys Prxs), thiol-based peroxidases able to reduce hydrogen and organic peroxides. At high peroxide concentrations the peroxidase function of 2-Cys Prxs may become inactivated through a process of overoxidation. This inactivation has been proposed to explain the signaling function of hydrogen peroxide in eukaryotes, whereas in prokaryotes, the 2-Cys Prxs of which were considered to be insensitive to overoxidation, the signaling activity of hydrogen peroxide is less relevant. Here we discuss the current knowledge about the mechanisms controlling 2-Cys Prx overoxidation in chloroplasts, organelles with an important signaling function in plants. Given the prokaryotic origin of chloroplasts, we discuss the occurrence of 2-Cys Prx overoxidation in cyanobacteria with the aim of identifying similarities between chloroplasts and their ancestors regarding their response to hydrogen peroxide.

  3. Effect of carbamide peroxide and hydrogen peroxide on enamel surface: an in vitro study.

    PubMed

    Abouassi, Thaer; Wolkewitz, Martin; Hahn, Petra

    2011-10-01

    The aim of the study was to investigate changes in the micromorphologyl and microhardness of the enamel surface after bleaching with two different concentrations of hydrogen peroxide (HP) and carbamide peroxide (CP). Bovine enamel samples were embedded in resin blocks, and polished. Specimens in the experimental groups (n = 10) were treated with bleaching gels containing 10% CP, 35% CP, 3.6% HP, and 10% HP, respectively, for 2 h every second day over a period of 2 weeks. The gels had the identical composition and pH and differed only in their HP or CP content. The roughness and morphology of the enamel surface were analyzed using laser profilometry and SEM. Microhardness was measured using a Knoop hardness tester. The data were evaluated statistically. Specimens in the 10% HP group showed significantly higher roughness after bleaching compared to the control group (ΔRa, p = 0.01). Bleaching with 35% CP showed only a tendency to increase roughness (ΔRa, p = 0.06). Application of 10% CP or 3.6% HP had no significant influence on Ra. Enamel microhardness was significantly higher after application of 10% HP compared to the control (ΔMic = 8 KHN, p = 0.0002) and 35% CP (ΔMic = 20KHN, p = 0.01) groups. In summary, application of CP and HP showed only small quantitative and qualitative differences. In addition, the influence of bleaching procedure on the morphology and hardness of the enamel surface depended on the concentration of the active ingredients.

  4. Evaluation of Extraradicular Diffusion of Hydrogen Peroxide during Intracoronal Bleaching Using Different Bleaching Agents

    PubMed Central

    Rokaya, Mohammad E.; Beshr, Khaled; Hashem Mahram, Abeer; Samir Pedir, Samah; Baroudi, Kusai

    2015-01-01

    Objectives. Extra radicular diffusion of hydrogen peroxide associated with intracoronal teeth bleaching was evaluated. Methods. 108 intact single rooted extracted mandibular first premolars teeth were selected. The teeth were instrumented with WaveOne system and obturated with gutta percha and divided into four groups (n = 27) according to the bleaching materials used. Each main group was divided into three subgroups (n = 9) according to the time of extra radicular hydrogen peroxide diffusion measurements at 1, 7, and 14 days: group 1 (35% hydrogen peroxide), group 2 (35% carbamide peroxide), group 3 (sodium perborate-30% hydrogen peroxide mixture), and group 4 (sodium perborate-water mixture). Four cemental dentinal defects were prepared just below the CEJ on each root surface. The amount of hydrogen peroxide that leached out was evaluated after 1, 7, and 14 days by spectrophotometer analysis. The results were analyzed using the ANOVA and Tukey's test. Results. Group 1 showed highest extra radicular diffusion, followed by group 3 and group 2, while group 4 showed the lowest mean extra radicular diffusion. Conclusion. Carbamide peroxide and sodium perborate-water mixture are the most suitable bleaching materials used for internal bleaching due to their low extra radicular diffusion of hydrogen peroxide. PMID:26257782

  5. Reaction of Aplysia limacina metmyoglobin with hydrogen peroxide.

    PubMed

    Svistunenko, Dimitri A; Reeder, Brandon J; Wankasi, Mieebi M; Silaghi-Dumitrescu, Radu-Lucian; Cooper, Chris E; Rinaldo, Serena; Cutruzzolà, Francesca; Wilson, Michael T

    2007-02-28

    Myoglobin (Mb) from gastropod mollusc Aplysia limacina shows only 20% sequence homology to the 'prototype' sperm whale Mb but exhibits a typical Mb fold and can reversibly bind oxygen. An intriguing feature of aplysia Mb is that it lacks the distal histidine and displays a ligand stabilisation based on an arginine. Here we report the reaction of aplysia metMb with hydrogen peroxide studied by optical and electron paramagnetic resonance (EPR) spectroscopies. Two electron oxidation of the protein by H2O2 results in formation of two intermediates typical for this class of reactions, the oxoferryl haem state and a globin-bound free radical. An unusual characteristic of the aplysia Mb reaction is formation, prior to haem oxidation, of an optically distinct compound with an EPR spectrum typical of the low spin Fe3+ haem state. This compound is interpreted as the complex between H2O2 and the ferric haem state (Compound), formed prior to cleavage of the dioxygen bond. We conclude that H2O2 is singly deprotonated in Compound which can thus be notated as [Fe3+--OOH]. A new low spin ferric haem state has been observed over the period of Compound decay, and hypotheses have been formulated as to its identity and role. The location of the protein bound radical observed in aplysia Mb is discussed in light of the fact that the protein does not have any tyrosine residues, the most common site of free radical formation in the haem protein/peroxide systems. All intermediates of the reaction are kinetically characterised.

  6. Kinetic release of hydrogen peroxide from different whitening products.

    PubMed

    da Silva Marques, Duarte Nuno; Silveira, Joao Miguel; Marques, Joana Rita; Amaral, Joao Almeida; Guilherme, Nuno Marques; da Mata, António Duarte

    2012-01-01

    The objective of this in vitro study was to evaluate the kinetics of hydrogen peroxide (HP) release from five different bleaching products: VivaStyle® 10% fitted tray gel, VivaStyle® 30% in-office bleaching gel, VivaStyle® Paint-On Plus paint-on bleaching varnish, Opalescence PF® 10% carbamide peroxide gel and Trèswhite Supreme™ 10% HP gel. Each product was firstly titrated for its HP content by a described method. HP release kinetics was assessed by a modified spectrophotometric technique. One sample t test was performed to test for differences between the manufacturers' claimed HP concentrations and the titrated HP content in the whitening products. Analysis of variance plus Tamhane's post hoc tests and Pearson correlation analysis were used as appropriate. Values of P < 0.05 were taken as significant. Titrated HP revealed an increased content when compared to the manufacturer's specifications for all the products tested (P < 0.05), although only products from one manufacturer produced significantly higher results. All products presented a significant (P < 0.05) and sustained release of HP. However, the product with paint-on cellulose-based matrix resulted in significantly (P < 0.05) faster kinetics when compared to other products tested. These results are consistent with manufacturers' reduced recommended application times. The results of this study suggest that modifying the matrix composition may be a viable alternative to HP concentration increase, since this may result in faster release kinetics without exposure to high HP concentrations. PMID:22908081

  7. Hydrogen peroxide-induced necrotic cell death in cardiomyocytes is independent of matrix metalloproteinase-2.

    PubMed

    Ali, Mohammad A M; Kandasamy, Arulmozhi D; Fan, Xiaohu; Schulz, Richard

    2013-09-01

    Matrix metalloproteinase-2 (MMP-2) is well known to proteolyse both extracellular and intracellular proteins. Reactive oxygen species activate MMP-2 at both transcriptional and post-translational levels, thus MMP-2 activation is considered an early event in oxidative stress injury. Although hydrogen peroxide is widely used to trigger oxidative stress-induced cell death, the type of cell death (apoptosis vs. necrosis) in cardiomyocytes is still controversial depending on the concentration used and the exposure time. We carefully investigated the mode of cell death in neonatal rat cardiomyocytes induced by different concentrations (50-500 μM) of hydrogen peroxide at various time intervals after exposure and determined whether MMP-2 is implicated in hydrogen peroxide-induced cardiomyocyte death. Treating cardiomyocytes with hydrogen peroxide led to elevated MMP-2 level/activity with maximal effects seen at 200 μM. Hydrogen peroxide caused necrotic cell death by disrupting the plasmalemma as evidenced by the release of lactate dehydrogenase in a concentration- and time-dependent manner as well as the necrotic cleavage of PARP-1. The absence of both caspase-3 cleavage/activation and apoptotic cleavage of PARP-1 illustrated the weak contribution of apoptosis. Pre-treatment with selective MMP inhibitors did not protect against hydrogen peroxide-induced necrosis. In conclusion hydrogen peroxide increases MMP-2 level/activity in cardiomyocytes and induces necrotic cell death, however, the later effect is MMP-2 independent.

  8. Development of biological and nonbiological explanations for the Viking label release data. [hydrogen peroxide theory

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The plausibility that hydrogen peroxide, widely distributed within the Mars surface material, was responsible for the evocative response obtained by the Viking Labeled Release (LR) experiment on Mars was investigated. Although a mixture of gamma Fe2O3 and silica sand stimulated the LR nutrient reaction with hydrogen peroxide and reduced the rate of hydrogen decomposition under various storage conditions, the Mars analog soil prepared by the Viking Inorganic Analysis Team to match the Mars analytical data does not cause such effects. Nor is adequate resistance to UV irradiation shown. On the basis of the results and consideration presented while the hydrogen peroxide theory remains the most, if not only, attractive chemical explanation of the LR data, it remains unconvincing on critical points. Until problems concerning the formation and stabilization of hydrogen peroxide on the surface of Mars can be overcome, adhere to the scientific evidence requires serious consideration of the biological theory.

  9. Factors affecting the levels of hydrogen peroxide in rainwater

    NASA Astrophysics Data System (ADS)

    Deng, Yiwei; Zuo, Yuegang

    Measurements of hydrogen peroxide (H 2O 2) and several meteorological and chemical parameters were made for 34 rain events which occurred in Miami, Florida between April, 1995 and October, 1996. The measured H 2O 2 concentrations ranged from 0.3 to 38.6 μM with an average concentration of 6.9 μM. A strong seasonal dependence for H 2O 2 concentrations was observed during this period, with highest concentrations in the summer and lower levels in the winter, which corresponds to the stronger solar radiation and higher vaporization of volatile organic compounds (VOCs) in the summer and fall, and the weaker sunlight and lower vaporization in the winter and spring. Measurements also showed a significant increase trend of H 2O 2 with increasing ambient rainwater temperature. Rains that were out from lower latitude were exposed to higher solar irradiation and contained relatively higher levels of H 2O 2 than those from the north. All these observations indicate that photochemical reactions that involved volatile organic compounds are the predominant source of H 2O 2 observed in rainwater. During several individual rainstorms, H 2O 2 concentration was found to increase as a function of time due to electrical storm activities. This finding suggests that lightning could be an important factor that determines the level of H 2O 2 during thunderstorms. Statistical data showed that the highest concentrations of H 2O 2 were observed only in rains containing low levels of nonsea-salt sulfate (NSS), nitrate and hydrogen ion. H 2O 2 concentrations in continental originated rains were much lower than marine originated ones, indicating that air pollutants in continental rains could significantly deplete the H 2O 2 concentration in atmospheric gas-phase, clouds and rainwater.

  10. Optimization of Hydrogen Peroxide Detection for a Methyl Mercaptan Biosensor

    PubMed Central

    Li, Zhan-Hong; Guedri, Houssemeddine; Viguier, Bruno; Sun, Shi-Gang; Marty, Jean-Louis

    2013-01-01

    Several kinds of modified carbon screen printed electrodes (CSPEs) for amperometric detection of hydrogen peroxide (H2O2) are presented in order to propose a methyl mercaptan (MM) biosensor. Unmodified, carbon nanotubes (CNTs), cobalt phthalocyanine (CoPC), Prussian blue (PB), and Os-wired HRP modified CSPE sensors were fabricated and tested to detect H2O2, applying a potential of +0.6 V, +0.6 V, +0.4 V, −0.2 V and −0.1 V (versus Ag/AgCl), respectively. The limits of detection of these electrodes for H2O2 were 3.1 μM, 1.3 μM, 71 nM, 1.3 μM, 13.7 nM, respectively. The results demonstrated that the Os-wired HRP modified CSPEs gives the lowest limit of detection (LOD) for H2O2 at a working potential as low as −0.1 V. Os-wired HRP is the optimum choice for establishment of a MM biosensor and gives a detection limit of 0.5 μM. PMID:23591963

  11. Nitric oxide formation from hydroxylamine by myoglobin and hydrogen peroxide.

    PubMed

    Taira, J; Misík, V; Riesz, P

    1997-10-20

    Hydroxylamine (HA), which is a natural product of mammalian cells, has been shown to possess vasodilatory properties in several model systems. In this study, HA and methyl-substituted hydroxylamines, N-methylhydroxylamine (NMHA) and N,N-dimethylhydroxylamine (NDMHA), have been tested for their ability to generate free diffusible nitric oxide (NO) in the presence of myoglobin (Mb) and hydrogen peroxide. A NO-specific conversion of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO) to 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl (carboxy-PTI), measured by electron spin resonance (ESR) spectroscopy, along with nitrite and nitrate production, was observed for HA but not for NMHA and NDMHA. ESR measurements at 77 K showed the formation of the ferrous nitrosyl myoglobin, Mb-NO, in the reaction mixtures containing Mb, H2O2 and HA. Our data also demonstrate that Mb-NO is an end product of the reaction pathway involving Mb, H2O2 and HA, rather than a reaction intermediate in the formation of NO. In summary, our results demonstrate a possible pathway of NO formation from HA, however, the significance of this mechanism for bioactivation of HA in vivo is unknown at the present time.

  12. Simultaneous electroanalysis of peroxyacetic acid and hydrogen peroxide.

    PubMed

    Awad, M I; Harnoode, C; Tokuda, K; Ohsaka, T

    2001-04-15

    The electrochemical behavior of peroxyacetic acid (PAA) in the presence of hydrogen peroxide (H2O2) has been investigated using cyclic voltammetry and hydrodynamic techniques [rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry]. The results have been analyzed aiming at simultaneous electroanalysis of both species. Glassy carbon and gold electrodes were used for this investigation. It was found that the reduction of PAA, as well as H2O2, is highly sensitive to the electrode material; for example, at 100 mV s-1, the reduction peak potentials of PAA were 0.2 and -1.1 V at gold and glassy carbon electrodes, respectively. The well-separated steady-state limiting currents were obtained using a gold electrode for the reduction of both PAA and H2O2 and also a well-defined one for the oxidation of H2O2. On the basis of the RDE experiments, good calibration curves were obtained for both species over a wide range of their concentrations, for PAA and H2O2 in the range of 0.36 to 110 and 0.11 to 34 mM, respectively. The simultaneous and selective electroanalysis of PAA and H2O2 in their coexistence is demonstrated for the first time.

  13. Salidroside inhibits endogenous hydrogen peroxide induced cytotoxicity of endothelial cells.

    PubMed

    Zhao, Xingyu; Jin, Lianhai; Shen, Nan; Xu, Bin; Zhang, Wei; Zhu, Hongli; Luo, Zhengli

    2013-01-01

    Salidroside, a phenylpropanoid glycoside isolated from Rhodiola rosea L., shows potent antioxidant property. Herein, we investigated the protective effects of salidroside against hydrogen peroxide (H2O2)-induced oxidative damage in human endothelial cells (EVC-304). EVC-304 cells were incubated in the presence or absence of low steady states of H2O2 (3-4 µM) generated by glucose oxidase (GOX) with or without salidroside. 3(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) assays were performed, together with Hoechst 33258 staining and flow cytometric analysis using Annexin-V and propidium iodide (PI) label. The results indicated that salidroside pretreatment attenuated endogenous H2O2 induced apoptotic cell death in EVC-304 cells in a dose-dependent pattern. Furthermore, Western blot data revealed that salidroside inhibited activation of caspase-3, 9 and cleavage of poly(ADP-ribose) polymerase (PARP) induced by endogenous H2O2. It also decreased the expression of Bax and rescued the balance of pro- and anti-apoptotic proteins. All these results demonstrated that salidroside may present a potential therapy for oxidative stress in cardiovascular and cerebrovascular diseases.

  14. Graphene Oxide Based Fluorometric Detection of Hydrogen Peroxide in Milk.

    PubMed

    Nanda, Sitansu Sekhar; Yi, Dong Kee; Kim, Kwangmeyung

    2016-01-01

    We report a highly rapid, visual, precise, selective and sensitive analytical method for the determination of hydrogen peroxide (H₂O₂) in milk using Graphene oxide (GO) with 2',7'-dichlorfluorescein diacetate (DCFH-DA). A 1000 µL aliquots of 10-fold diluted samples (high and low-fat milk) directly onto the 100 µL of GO and 100 µL of 100 µM DCFH-DA produced green colour under Ultraviolet light at 365 nm. The analytical feature of our proposed method includes low detection limit (10 mmol mL⁻¹) and satisfactory recovery values for samples. The presence of H202 in milk is a major concern because it constitutes a public health hazard. Many milk indursties are using H₂O₂ as a preservative, but if the concentration increases then it causes so many health problems such as neurodegenerative disorders, cancer and diabetes. Present methods show an easy way for detecting H₂O₂ generally require considerable time and laboratory facilities. The chemical tests have sufficient sensitivity to detect wide linear range of H₂O₂ concentration. PMID:27398583

  15. An investigation of hydrogen-peroxide reduction and decomposition catalysts

    SciTech Connect

    Kicheev, A.G.; Kalmykova, S.B.; Kvashnin, Yu.A.; Maksimov, G.N.; Savel'eva, V.N.

    1986-01-01

    Silver and platinum metals are known as active catalysts for hydrogen peroxide reduction and decomposition. But their relative activities are not well known, and data are also lacking with respect to the relative rates of reduction and decomposition of H/sub 2/O/sub 2/ at different catalysts. It was the aim of this work to study the rates of H/sub 2/O/sub 2/ reduction and decomposition at different electrodes which are catalytically active in these reactions and relatively corrosion-resistant in alkaline solutions. The authors studied the metals Ag, Au, Pt, and Pd, the alloy Pd-Ru, the surface Raney-nickel catalyst Ni-SRC, as well as Ni-SRC coated with an electrolytic palladium deposit, Pd/Ni-SRC. In this work the potentiodynamic curves of H/sub 2/O/sub 2/ reduction were recorded with a scan rate of 40 mV/min at the electrodes being investigated.

  16. Activation of Store-Operated ICRAC by Hydrogen Peroxide

    PubMed Central

    Grupe, Morten; Myers, George; Penner, Reinhold; Fleig, Andrea

    2010-01-01

    SUMMARY Reactive oxygen species such as hydrogen peroxide (H2O2) play a role in both innate immunity as well as cellular injury. H2O2 induces changes in intracellular calcium ([Ca2+]i) in many cell types and this seems to be at least partially mediated by transient receptor potential melastatin 2 (TRPM2) in cells that express this channel. Here we show that low concentrations of H2O2 induce the activation of the Ca2+-release activated Ca2+ current ICRAC. This effect is not mediated by direct CRAC channel activation, since H2O2 does not activate heterologously expressed CRAC channels independently of stromal interaction molecule (STIM). Instead, ICRAC activation is partially mediated by store depletion through activation of inositol 1,4,5 trisphosphate receptors (IP3R), since pharmacological inhibition of IP3 receptors by heparin or molecular knock-out of all IP3 receptors in DT40 B cells strongly reduce H2O2-induced ICRAC. The remainder of H2O2-induced ICRAC activation is likely mediated by IP3R-independent store-depletion. Our data suggest that H2O2 can activate Ca2+ entry through TRPM2 as well as store-operated CRAC channels, thereby adding a new facet to ROS-induced Ca2+ signaling. PMID:20646759

  17. Specific aquaporins facilitate the diffusion of hydrogen peroxide across membranes.

    PubMed

    Bienert, Gerd P; Møller, Anders L B; Kristiansen, Kim A; Schulz, Alexander; Møller, Ian M; Schjoerring, Jan K; Jahn, Thomas P

    2007-01-12

    The metabolism of aerobic organisms continuously produces reactive oxygen species. Although potentially toxic, these compounds also function in signaling. One important feature of signaling compounds is their ability to move between different compartments, e.g. to cross membranes. Here we present evidence that aquaporins can channel hydrogen peroxide (H2O2). Twenty-four aquaporins from plants and mammals were screened in five yeast strains differing in sensitivity toward oxidative stress. Expression of human AQP8 and plant Arabidopsis TIP1;1 and TIP1;2 in yeast decreased growth and survival in the presence of H2O2. Further evidence for aquaporin-mediated H2O2 diffusion was obtained by a fluorescence assay with intact yeast cells using an intracellular reactive oxygen species-sensitive fluorescent dye. Application of silver ions (Ag+), which block aquaporin-mediated water diffusion in a fast kinetics swelling assay, also reversed both the aquaporin-dependent growth repression and the H2O2-induced fluorescence. Our results present the first molecular genetic evidence for the diffusion of H2O2 through specific members of the aquaporin family.

  18. Solvothermal method to prepare graphene quantum dots by hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Tian, Renbing; Zhong, Suting; Wu, Juan; Jiang, Wei; Shen, Yewen; Jiang, Wei; Wang, Tianhe

    2016-10-01

    Graphene quantum dots (GQDs) have been synthesized by different chemical methods in recent years. For conventional chemical methods, it is inevitable to introduce a large amount of impurities in the preparation process. Long time of dialysis process increases the time cost extremely. Herein, we report a one-step solvothermal method for synthesizing GQDs with the application of hydrogen peroxide in N, N-Dimethylformamide (DMF) environment, which completely avoids the use of concentrated sulphuric acid and nitric acid to treat raw material and introduces no impurity in whole preparation process simultaneously for the first time. Pure GQDs can be obtained after evaporation/redissolution and filtration process with a strong blue emission at 15% quantum yield. This solvothermal method, not requiring dialysis process and complicated equipments, exhibits simple, eco-friendly and low time-cost properties. Besides high quantum yields, the as-prepared GQDs also show good photoluminescence stability in different pH conditions. The optical properties, morphology and structure of GQDs were studied by various equipments, implying potential application in biomedical fields and electronic device.

  19. Ab initio calculation of infrared intensities for hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Rogers, J. D.; Hillman, J. J.

    1982-01-01

    Results of an ab initio SCF quantum mechanical study are used to derive estimates for the infrared intensities of the fundamental vibrations of hydrogen peroxide. Atomic polar tensors (APTs) were calculated on the basis of a 4-31G basis set, and used to derive absolute intensities for the vibrational transitions. Comparison of the APTs calculated for H2O2 with those previously obtained for H2O and CH3OH, and of the absolute intensities derived from the H2O2 APTs with those derived from APTs transferred from H2O and CH3OH, reveals the sets of values to differ by no more than a factor of two, supporting the validity of the theoretical calculation. Values of the infrared intensities obtained correspond to A1 = 14.5 km/mol, A2 = 0.91 km/mol, A3 = 0.058 km/mol, A4 = 123 km/mol, A5 = 46.2 km/mol, and A6 = 101 km/mol. Charge, charge flux and overlap contributions to the dipole moment derivatives are also computed.

  20. Mononuclear Iron Enzymes Are Primary Targets of Hydrogen Peroxide Stress*

    PubMed Central

    Anjem, Adil; Imlay, James A.

    2012-01-01

    This study tested whether nonredox metalloenzymes are commonly charged with iron in vivo and are primary targets of oxidative stress because of it. Indeed, three sample mononuclear enzymes, peptide deformylase, threonine dehydrogenase, and cytosine deaminase, were rapidly damaged by micromolar hydrogen peroxide in vitro and in live Escherichia coli. The first two enzymes use a cysteine residue to coordinate the catalytic metal atom; it was quantitatively oxidized by the radical generated by the Fenton reaction. Because oxidized cysteine can be repaired by cellular reductants, the effect was to avoid irreversible damage to other active-site residues. Nevertheless, protracted H2O2 exposure gradually inactivated these enzymes, consistent with the overoxidation of the cysteine residue to sulfinic or sulfonic forms. During H2O2 stress, E. coli defended all three proteins by inducing MntH, a manganese importer, and Dps, an iron-sequestration protein. These proteins appeared to collaborate in replacing the iron atom with nonoxidizable manganese. The implication is that mononuclear metalloproteins are common targets of H2O2 and that both structural and metabolic arrangements exist to protect them. PMID:22411989

  1. Hydrogen peroxide regulates cell adhesion through the redox sensor RPSA.

    PubMed

    Vilas-Boas, Filipe; Bagulho, Ana; Tenente, Rita; Teixeira, Vitor H; Martins, Gabriel; da Costa, Gonçalo; Jerónimo, Ana; Cordeiro, Carlos; Machuqueiro, Miguel; Real, Carla

    2016-01-01

    To become metastatic, a tumor cell must acquire new adhesion properties that allow migration into the surrounding connective tissue, transmigration across endothelial cells to reach the blood stream and, at the site of metastasis, adhesion to endothelial cells and transmigration to colonize a new tissue. Hydrogen peroxide (H2O2) is a redox signaling molecule produced in tumor cell microenvironment with high relevance for tumor development. However, the molecular mechanisms regulated by H2O2 in tumor cells are still poorly known. The identification of H2O2-target proteins in tumor cells and the understanding of their role in tumor cell adhesion are essential for the development of novel redox-based therapies for cancer. In this paper, we identified Ribosomal Protein SA (RPSA) as a target of H2O2 and showed that RPSA in the oxidized state accumulates in clusters that contain specific adhesion molecules. Furthermore, we showed that RPSA oxidation improves cell adhesion efficiency to laminin in vitro and promotes cell extravasation in vivo. Our results unravel a new mechanism for H2O2-dependent modulation of cell adhesion properties and identify RPSA as the H2O2 sensor in this process. This work indicates that high levels of RPSA expression might confer a selective advantage to tumor cells in an oxidative environment.

  2. The role of hydrogen peroxide in endothelial proliferative responses.

    PubMed

    Stone, James R; Collins, Tucker

    2002-01-01

    Hydrogen peroxide (H2O2) is a recently recognized second messenger regulating proliferation in mammalian cells. Endothelial cells possess NADPH oxidases, which produce the H202 precursor superoxide (.O2-) in response to receptor-mediated signaling. Multiple physiologic agents have been shown to stimulate endothelial cells to produce .O2-/H2O2, including growth factors, such as vascular endothelial growth factor and transforming growth factor-beta1, and alterations in biomechanical forces, such as shear stress and cyclic strain. Downstream effects of these stimuli can often be inhibited by scavenging H2O2. Low concentrations of H2O2 stimulate proliferation or enhanced survival in a wide variety of cell types. Also, low concentrations of H2O2 stimulate endothelial migration as well as tube formation in an in vitro model of angiogenesis. Although low concentrations of H2O2 have been shown to be involved in numerous signal transduction pathways and to independently stimulate mitogenesis, there has been little information presented on precisely how mammalian cells respond biochemically to these low concentrations of H2O2. Recently a functional proteomics approach has been utilized to identify proteins responsive to low concentrations of H2O2 in human endothelial cells.

  3. Hydrogen peroxide-induced chemotaxis of mouse peritoneal neutrophils.

    PubMed

    Klyubin, I V; Kirpichnikova, K M; Gamaley, I A

    1996-08-01

    Directed locomotion of mouse peritoneal neutrophils under agarose was studied, and activity of hydrogen peroxide (H2O2) as a chemoattractant was tested in its concentration range of 10(-6) to 10(-3) M. It has been found that H2O2 at low concentrations (about 10 microM) induces chemotactic activity. This activity was not affected by the presence of serum in the agarose medium. Use of bovine serum albumin instead of the heat-inactivated bovine serum in the medium had no effect on cell locomotion. The H2O2-induced chemotaxis was significantly reduced by catalase. Involvement of [Ca2+]i transients in the H2O2-induced chemotactic response was shown. These data indicate that H2O2 itself in small quantities can act as a chemoattractant without interacting with a plasma precursor to form a chemotactic factor. It has been suggested that H2O2 may form an important link similar to the second messenger in communication between the cells.

  4. Hydrogen Peroxide-Induced Akt Phosphorylation Regulates Bax Activation

    PubMed Central

    Sadidi, Mahdieh; Lentz, Stephen I.; Feldman, Eva L.

    2009-01-01

    Reactive oxygen species such as hydrogen peroxide (H2O2) are involved in many cellular processes that positively and negatively regulate cell fate. H2O2, acting as an intracellular messenger, activates phosphatidylinositol-3 kinase (PI3K) and its downstream target Akt, and promotes cell survival. The aim of the current study was to understand the mechanism by which PI3K/Akt signaling promotes survival in SH-SY5Y neuroblastoma cells. We demonstrate that PI3K/Akt mediates phosphorylation of the pro-apoptotic Bcl-2 family member Bax. This phosphorylation suppresses apoptosis and promotes cell survival. Increased survival in the presence of H2O2 was blocked by LY294002, an inhibitor of PI3K activation. LY294002 prevented Bax phosphorylation and resulted in Bax translocation to the mitochondria, cytochrome c release, caspase-3 activation, and cell death. Collectively, these findings reveal a mechanism by which H2O2-induced activation of PI3K/Akt influences posttranslational modification of Bax and inactivate a key component of the cell death machinery. PMID:19278624

  5. Further Studies of Materials Compatibility in High-Test Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Gostowski, R.; Owens, T.

    2001-01-01

    Assessment of the compatibility of high-test hydrogen peroxide (HTP) with materials, in particular new materials such as composites, is critical to the development of new propulsion systems meeting requirements of reduced cost and environmental impact. While compatibility with HTP has been addressed previously, newer materials were not considered. The focus of this project was to develop a scheme for evaluation of HTP with all materials. In the previous summer, methods were developed for production of HTP on site, and preliminary steps were taken to evaluate materials. Methods investigated this summer have included accelerated aging by heating, coupled with assay of concentration and stabilization loss, observation of reactivity by means of Isothermal Microcalorimetry, and evaluation of changes to the materials by Short Beam Shear testing and by Photoacoustic-Fourier Transform Infrared Spectroscopy. Various metals, polymers, and composites were examined in this study.

  6. Decomposition of acetone by hydrogen peroxide/ozone process in a rotating packed contactor.

    PubMed

    Ku, Young; Huang, Yun-Jen; Chen, Hua-Wei; Hou, Wei-Ming

    2011-07-01

    The direct use of ozone (O3) in water and wastewater treatment processes is found to be inefficient, incomplete, and limited by the ozone transfer between the gas-liquid interface because of its low solubility and instability in aqueous solutions. Therefore, rotating packed contactors were introduced to improve the transfer of ozone from the gaseous phase to the solution phase, and the effect of several reaction parameters were investigated on the temporal variations of acetone concentration in aqueous solution. The decomposition rate constant of acetone was enhanced by increasing the rotor speed from 450 to 1800 rpm. Increasing the hydrogen peroxide (H2O2)/O3 molar ratios accelerated the decomposition rate until a certain optimum H2O2/O3 molar ratio was reached; further addition of H2O2 inhibited the decomposition of acetone, possibly because excessive amounts of H2O2 added might serve as a scavenger to deplete hydroxyl free radicals.

  7. A HIGHLY EFFICIENT OXIDATION OF CYCLOHEXANE OVER VPO CATALYSTS USING HYDROGEN PEROXIDE

    EPA Science Inventory

    An unprecedented and highly efficient oxidation of cyclohexane to cyclohexanol and cyclohexanone is accomplished over calcined vanadium phosphorus oxide (VPO) catalysts in a relatively mild condition using hydrogen peroxide under a nitrogen atmosphere.

  8. [The Clinical Application Status and Development Trends of Hydrogen Peroxide Low Temperature Plasma Sterilizers].

    PubMed

    Zhuang, Min; Zheng, Yunxin; Chen, Ying; Hou, Bin; Xu, Zitian

    2016-01-01

    The hydrogen peroxide low temperature plasma sterilization technology solved the problems of thermo-sensitive materials' disinfection and sterilization based on its development and unique characteristics. This paper introduced the researches of clinical application quality control, and showed the hydrogen peroxide low temperature plasma sterilizers were being widely used in hospitals and highly recognized. According to the clinical data and the literatures of the domestic equipment in preliminary application, it could be concluded that the technology maturity of domestic hydrogen peroxide low temperature plasma sterilizers was in a high level. The advantages of using domestic hydrogen peroxide low temperature plasma sterilizers to do disinfection and sterilization included lower cost, safer, faster and non-toxic, etc. Also the management system should be improved and the clinical staff should master the technical essentials, obey the procedures strictly, verify periodically and offer full monitoring to upgrade the quality of sterilization. PMID:27197500

  9. Effect of hydrogen peroxide treatment on the properties of wool fabric

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Shen, Xiaolin; Xu, Weilin

    2012-10-01

    In this study, hydrogen peroxide treatment was applied to improve the surface wettability, moisture transfer properties and other related properties of wool fabric. SEM images showed the tip of wool scale was smoothened and parts of the scale were peeled off after hydrogen peroxide treatment. The time for a water droplet to sink into the fabric could decrease to less than 1 s and the wicking properties of wool fabrics were dramatically improved after hydrogen peroxide treatment. Shrinkage and whiteness of the fabric were improved due to the modification of scale and the bleaching effect of hydrogen peroxide, respectively. The fabrics became weaker and ductile with less than 4% weight loss. This study would benefit further application of wool fiber in summer clothing in which the surface wettability and moisture transfer properties are essential and determinative.

  10. Treatment of Aroclor 1016 contaminated soil by hydrogen peroxide: laboratory column study.

    PubMed

    Viisimaa, Marika; Veressinina, Jelena; Goi, Anna

    2012-09-01

    The potential and feasibility of treating soil contaminated with electrical insulating oil, Aroclor 1016, containing polychlorinated biphenyls (PCBs) with stabilized hydrogen peroxide were evaluated using columns packed with soils of two different matrixes. The column experiments showed that PCBs degraded by the stabilized hydrogen peroxide treatment in both soil matrixes, although the efficacy of the treatment depended strongly on the soil characteristics. The removal of PCB-containing oil was higher in sandy silt soil than in sandy soil. While a higher iron content promoted hydrogen peroxide oxidation of the contaminant in sandy silt soil, lower permeability and higher organic matter content contributed to an oxidation decrease as a function of depth. Dehydrogenase activity measurements indicated no substantial changes in microbial activity during the treatment of both sandy and sandy silt soils, thus offering opportunities to apply the hydrogen peroxide treatment to the remediation of PCB-contaminated soil.

  11. [The Clinical Application Status and Development Trends of Hydrogen Peroxide Low Temperature Plasma Sterilizers].

    PubMed

    Zhuang, Min; Zheng, Yunxin; Chen, Ying; Hou, Bin; Xu, Zitian

    2016-01-01

    The hydrogen peroxide low temperature plasma sterilization technology solved the problems of thermo-sensitive materials' disinfection and sterilization based on its development and unique characteristics. This paper introduced the researches of clinical application quality control, and showed the hydrogen peroxide low temperature plasma sterilizers were being widely used in hospitals and highly recognized. According to the clinical data and the literatures of the domestic equipment in preliminary application, it could be concluded that the technology maturity of domestic hydrogen peroxide low temperature plasma sterilizers was in a high level. The advantages of using domestic hydrogen peroxide low temperature plasma sterilizers to do disinfection and sterilization included lower cost, safer, faster and non-toxic, etc. Also the management system should be improved and the clinical staff should master the technical essentials, obey the procedures strictly, verify periodically and offer full monitoring to upgrade the quality of sterilization.

  12. SnFe2 O4 Nanocrystals as Highly Efficient Catalysts for Hydrogen-Peroxide Sensing.

    PubMed

    Lee, Kuan-Ting; Liu, Dai-Ming; Lu, Shih-Yuan

    2016-07-25

    SnFe2 O4 nanocrystals (NC), prepared with a simple one-step carrier-solvent-assisted interfacial reaction process, were developed as highly efficient catalysts for hydrogen peroxide sensing. These NCs, with a size of around 7 nm, served as the sensing catalyst and were decorated onto the pore surfaces of a porous fluorine-doped tin oxide (PFTO) host electrode, prepared from commercial FTO glass with a simple anodic treatment, to form the sensing electrode for hydrogen peroxide. The SnFe2 O4 NCs-loaded PFTO electrode exhibited an ultra-high sensitivity of 1027 mA m(-1)  cm(-2) toward hydrogen peroxide, outperforming Pt NCs-loaded PFTO electrodes. The SnFe2 O4 NCs-loaded PFTO electrode proved a promising relatively low cost, high performance sensing electrode for hydrogen peroxide. PMID:27346720

  13. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BIOQUELL, INC. CLARIS C HYDROGEN PEROXIDE GAS GENERATOR

    EPA Science Inventory

    The Environmental Technology Verification report discusses the technology and performance of the Clarus C Hydrogen Peroxide Gas Generator, a biological decontamination device manufactured by BIOQUELL, Inc. The unit was tested by evaluating its ability to decontaminate seven types...

  14. Certification of vapor phase hydrogen peroxide sterilization process for spacecraft application

    NASA Technical Reports Server (NTRS)

    Rohatgi, N.; Schubert, W.; Koukol, R.; Foster, T. L.; Stabekis, P. D.

    2002-01-01

    This paper describes the selection process and research activities JPL is planning to conduct for certification of hydrogen peroxide as a NASA approved technique for sterilization of various spacecraft parts/components and entire modern spacecraft.

  15. Development of technology of hydrogen peroxide water treatment with use of homogeneous or heterogeneous catalysts

    NASA Astrophysics Data System (ADS)

    Gutenyev, V. V.; Azhgirevich, A. I.; Kiryanova, L. F.; Gutenyeva, Ye. N.

    2003-04-01

    A flow chart of water disinfection by hydrogen peroxide with the use, as a catalyst, of manganese dioxide and titanium dioxide, as well as of natural catalysts, such as hopcolite, pyrolusite, rutil. The analysis of collected data shows that combination of hydrogen peroxide with hopcolite powder appears to be the most effective. Another positive aspect of the mentioned combination is enabling (by hopcolite) the water treated by hydrogen peroxide to continuously resist secondary bacteriological contamination. This flow chart enables us to increase the effectiveness of disinfection of hydrogen peroxide, which reduces human impact on environment. In order to improve bactericidal effects of hopcolite we loaded the hopcolite powder with metallic silver particles. In a series of experiments held both with environmental water and with model solutions we found the ability to neutralize artificially introduced infection (102 cells per liter) in 1.5-2 days.

  16. HOMOGENEOUS CATALYSTS FOR THE PARTIAL-OXYGENATION OF SATURATED HYDROCARBONS WITH HYDROGEN PEROXIDE

    EPA Science Inventory

    The development of catalysts with the capacity to activate green oxidants, such as hydrogen peroxide and molecular oxygen, can offer an environmentally sound pathway for hydrocarbon oxidation. Furthermore, by including the concepts of green chemistry and pollution prevention one ...

  17. Hydrogen peroxide induces microvilli on human retinal pigment epithelial cells in culture.

    PubMed

    Reid, G G; Edwards, J G; Marshall, G E; Sutcliffe, R G; Lee, W R

    1995-02-01

    We have found that hydrogen peroxide (10(-4)-10(-2) M) rapidly induces microvilli on separate cells and confluent sheets of human retinal pigment epithelium in culture. t-butyl hydroperoxide and sodium arsenite do not induce microvilli. A role for hydrogen peroxide as an intercellular messenger has previously been proposed in the inflammatory response, in which hydrogen peroxide from phagocytes may signal to vascular endothelial cells. Our observations thus provide a second example of the induction of what may be a physiological response by this potentially toxic agent. In the retina, hydrogen peroxide released from illuminated photoreceptors may elongate the microvilli which extend into the spaces between them. Increased numbers of microvilli and their protrusion further into the photoreceptor layer may enhance various interactions between the two cell types, including the antioxidant functions of the epithelium.

  18. MICROWAVE-EXPEDITED OLEFIN EPOXIDATION OVER HYDROTALCITES USING HYDROGEN PEROXIDE AND ACETONITRILE

    EPA Science Inventory

    An efficient microwave-assisted expoxidation of olefins is described over hydrotalcite catalysts in the presence of hydrogen peroxide and acetonitrile. This general and selective protocol is extremely fast and is applicable to a wide variety of subtrates.

  19. ENHANCED BIOREMEDIATION UTILIZING HYDROGEN PEROXIDE AS A SUPPLEMENTAL SOURCE OF OXYGEN: A LABORATORY AND FIELD STUDY

    EPA Science Inventory

    Laboratory and field scale studies were conducted to investigate the feasibility of using hydrogen peroxide as a supplemental source of oxygen for bioremediation of an aviation gasoline fuel spill. Field samples of aviation gasoline contaminated aquifer material were artificially...

  20. An automated system for the measurement of hydrogen peroxide in industrial applications

    PubMed Central

    Westbroek, Philippe; Temmerman, Edward; Kiekens, Paul; Govaert, Filip

    1998-01-01

    An automated sensor system for the continuous and in-line measurement of hydrogen peroxide in industrial applications is described. The hydrogen peroxide concentration can be measured over the entire pH range, over a wide concentration range of hydrogen peroxide (10-3 70 g/l), from 0 to 70°C, and with high precision and accuracy (errors less than 1% ). The system consists of a bypass in which the necessary electrodes are positioned and electronically controlled. The sensor is very selective for hydrogen peroxide, easy to instal, and it is stable for at least two months after calibration. The calibration can be done in the process solution during a running process. PMID:18924833

  1. Developing Planetary Protection Technology: Recurrence of Hydrogen Peroxide Resistant Microbes from Spacecraft Assembly Facilities

    NASA Astrophysics Data System (ADS)

    Kempf, M. J.; Chen, F.; Quigley, M. S.; Pillai, S.; Kern, R.; Venkateswaran, K.

    2001-12-01

    Hydrogen peroxide vapor is currently the sterilant-of-choice for flight hardware because it is a low-heat sterilization process suitable for use with various spacecraft components. Hydrogen peroxide is a strong oxidizing agent that produces hydroxyl free radicals ( .OH) which attack essential cell components, including lipids, proteins, and DNA. Planetary protection research efforts at the Jet Propulsion Laboratory (JPL) are focused on developing cleaning and sterilization technologies for spacecraft preparation prior to launch. These efforts include research to assess the microbial diversity of spacecraft assembly areas and any extreme characteristics these microbes might possess. Previous studies have shown that some heat-tolerant Bacillus species isolated from the JPL Spacecraft Assembly Facility (SAF) are resistant to recommended hydrogen peroxide vapor sterilization exposures. A Bacillus species, which was related to a hydrogen peroxide resistant strain, was repeatedly isolated from various locations in the JPL-SAF. This species was found in both unclassified (entrance floors, ante-room, and air-lock) and classified (class 100K) (floors, cabinet tops, and air) areas. The phylogenetic affiliation of these strains was carried out using biochemical tests and 16S rDNA sequencing. The 16S rDNA analysis showed >99% sequence similarity to Bacillus pumilus. In order to understand the epidemiology of these strains, a more highly evolved gene (topoisomerase II β -subunit, gyrB) was also sequenced. Among 4 clades, one cluster, comprised of 3 strains isolated from the air-lock area, tightly aligned with the B. pumilus ATCC 7061 type strain (97%). The gyrB sequence similarity of this clade was only 91% with the 3 other clades. The genetic relatedness of these strains, as per pulse field gel electrophoresis patterns, will be presented. The vegetative cells and spores of a number of isolates were tested for their hydrogen peroxide resistance. Cells and spores were

  2. Cerebral arterial gas embolism after pre-flight ingestion of hydrogen peroxide.

    PubMed

    Smedley, Ben L; Gault, Alan; Gawthrope, Ian C

    2016-06-01

    Cerebral arterial gas embolism (CAGE) is a feared complication of ambient depressurisation and can also be a complication of hydrogen peroxide ingestion. We present an unusual case of CAGE in a 57-year-old woman exposed to both of these risk factors. We describe her subsequent successful treatment with hyperbaric oxygen, despite a 72-hour delay in initial presentation and diagnosis, and discuss the safety of aero-medical transfer following hydrogen peroxide ingestions.

  3. Efficacy of hydrogen peroxide to control saprolegniasis on channel catfish (Ictalurus punctatus) eggs

    USGS Publications Warehouse

    Rach, J.J.; Valentine, J.J.; Schreier, T.M.; Gaikowski, M.P.; Crawford, T.G.

    2004-01-01

    The efficacy of hydrogen peroxide to control mortality associated with saprolegniasis in channel catfish (Ictalurus punctatus) eggs was evaluated at the Lost Valley State Fish Hatchery (Warsaw, MO). Two efficacy trials were conducted. In Trial 1, channel catfish eggs in their natural gelatinous matrix were treated with hydrogen peroxide at 0, 500, and 750 mg l(-1). Channel catfish eggs in Trial 2 had the gelatinous matrix removed before treatment with hydrogen peroxide at 0 and 500 mg l(-1). Each treatment regimen was tested in triplicate and each egg jar contained similar to 17,400 eggs. Hydrogen peroxide was administered as a 15-min flow-through treatment applied once daily for a total of six applications. Control jars were similarly treated with culture water. Samples of exposure water were collected during each treatment and analyzed to verify actual treatment concentrations. Hydrogen peroxide treatment efficacy was assessed by comparing the percent egg hatch in the treatment group to the untreated control group in each trial. Mean percent hatch in Trial I was 44% (control), 54% (500 mg l(-1)), and 69% (750 mg l(-1)). Hydrogen peroxide treatment at either 500 or 750 mg l(-1) significantly (P<0.01) increased the percent hatch compared to the untreated control group. In Trial 2, hydrogen peroxide treatment at 500 mg l(-1) significantly (P<0.01) increased the percent egg hatch (67%) relative to the untreated controls (57%). Hydrogen peroxide treatment reduced egg mortality and increased the percent hatch of channel catfish eggs regardless of whether eggs were incubated in the gelatinous matrix or without the matrix in comparison to the untreated control. (C) 2004 Elsevier B.V. All rights reserved.

  4. Cerebral arterial gas embolism after pre-flight ingestion of hydrogen peroxide.

    PubMed

    Smedley, Ben L; Gault, Alan; Gawthrope, Ian C

    2016-06-01

    Cerebral arterial gas embolism (CAGE) is a feared complication of ambient depressurisation and can also be a complication of hydrogen peroxide ingestion. We present an unusual case of CAGE in a 57-year-old woman exposed to both of these risk factors. We describe her subsequent successful treatment with hyperbaric oxygen, despite a 72-hour delay in initial presentation and diagnosis, and discuss the safety of aero-medical transfer following hydrogen peroxide ingestions. PMID:27335000

  5. Bioremediation of chlorobenzene-contaminated ground water in an in situ reactor mediated by hydrogen peroxide.

    PubMed

    Vogt, Carsten; Alfreider, Albin; Lorbeer, Helmut; Hoffmann, Doreen; Wuensche, Lothar; Babel, Wolfgang

    2004-01-01

    New in situ reactive barrier technologies were tested nearby a local aquifer in Bitterfeld, Saxonia-Anhalt, Germany, which is polluted mainly by chlorobenzene (CB), in concentrations up to 450 microM. A reactor filled with original aquifer sediment was designed for the microbiological remediation of the ground water by indigenous bacterial communities. Two remediation variants were examined: (a) the degradation of CB under anoxic conditions in the presence of nitrate; (b) the degradation of CB under mixed electron acceptor conditions (oxygen+nitrate) using hydrogen peroxide as the oxygen-releasing compound. Under anoxic conditions, no definite degradation of CB was observed. Adding hydrogen peroxide (2.94 mM) and nitrate (2 mM) led to the disappearance of CB (ca. 150 microM) in the lower part of the reactor, accompanied by a strong increase of the number of cultivable aerobic CB degrading bacteria in reactor water and sediment samples, indicating that CB was degraded mainly by productive bacterial metabolism. Several aerobic CB degrading bacteria, mostly belonging to the genera Pseudomonas and Rhodococcus, were isolated from reactor water and sediments. In laboratory experiments with reactor water, oxygen was rapidly released by hydrogen peroxide, whereas biotic-induced decomposition reactions of hydrogen peroxide were almost four times faster than abiotic-induced decomposition reactions. A clear chemical degradation of CB mediated by hydrogen peroxide was not observed. CB was also completely degraded in the reactor after reducing the hydrogen peroxide concentration to 880 microM. The CB degradation completely collapsed after reducing the hydrogen peroxide concentration to 440 microM. In the following, the hydrogen peroxide concentrations were increased again (to 880 microM, 2.94 mM, and 880 microM, respectively), but the oxygen demand for CB degradation was higher than observed before, indicating a shift in the bacterial population. During the whole experiment

  6. Strategies for designing supported gold-palladium bimetallic catalysts for the direct synthesis of hydrogen peroxide.

    PubMed

    Edwards, Jennifer K; Freakley, Simon J; Carley, Albert F; Kiely, Christopher J; Hutchings, Graham J

    2014-03-18

    Hydrogen peroxide is a widely used chemical but is not very efficient to make in smaller than industrial scale. It is an important commodity chemical used for bleaching, disinfection, and chemical manufacture. At present, manufacturers use an indirect process in which anthraquinones are sequentially hydrogenated and oxidized in a manner that hydrogen and oxygen are never mixed. However, this process is only economic at a very large scale producing a concentrated product. For many years, the identification of a direct process has been a research goal because it could operate at the point of need, producing hydrogen peroxide at the required concentration for its applications. Research on this topic has been ongoing for about 100 years. Until the last 10 years, catalyst design was solely directed at using supported palladium nanoparticles. These catalysts require the use of bromide and acid to arrest peroxide decomposition, since palladium is a very active catalyst for hydrogen peroxide hydrogenation. Recently, chemists have shown that supported gold nanoparticles are active when gold is alloyed with palladium because this leads to a significant synergistic enhancement in activity and importantly selectivity. Crucially, bimetallic gold-based catalysts do not require the addition of bromide and acids, but with carbon dioxide as a diluent its solubility in the reaction media acts as an in situ acid promoter, which represents a greener approach for peroxide synthesis. The gold catalysts can operate under intrinsically safe conditions using dilute hydrogen and oxygen, yet these catalysts are so active that they can generate peroxide at commercially significant rates. The major problem associated with the direct synthesis of hydrogen peroxide concerns the selectivity of hydrogen usage, since in the indirect process this factor has been finely tuned over decades of operation. In this Account, we discuss how the gold-palladium bimetallic catalysts have active sites for the

  7. Acute toxicity of hydrogen peroxide treatments to selected lifestages of cold-, cool-, and warmwater fish

    USGS Publications Warehouse

    Gaikowski, Mark P.; Rach, Jeffery J.; Ramsay, Robert T.

    1999-01-01

    Hatchery personnel depend on therapeutant treatments to control diseases. Currently, hatchery managers in the United States are limited to one approved therapeutant (formalin) and three compounds of Low Regulatory Priority (sodium chloride, hydrogen peroxide, and acetic acid) to control external diseases of cultured fish. Hydrogen peroxide has been used to effectively control external columnaris and bacterial gill disease in rainbow trout, however, definitive safe treatment concentrations for hydrogen peroxide are lacking for a variety of species. We report the acute toxicity of hydrogen peroxide treatments to 11 species of fry and 13 species of fingerling freshwater fish. Most mortality occurred within the first 30 h after the first exposure to hydrogen peroxide with little change in the overall shape of survival curves over time. Our data predict that in an actual therapeutic application of hydrogen peroxide, most treatment-related mortalities would be observed shortly after the initial exposure. Coolwater species were more sensitive than coldwater species but were generally similar to warmwater species tested. Based on our mortality data, coldwater species and largemouth bass may be treated for 60 min at concentrations of ≤ 150 (μl/1 without harmful effects; all muskellunge, walleye, bluegill, channel catfish, yellow perch, pallid sturgeon fingerlings, fathead minnow fingerlings, white sucker fingerlings, and northern pike fry may be treated for 60 min at ≤ 100 μl/l; and northern pike fingerlings and white sucker, yellow perch and fathead minnow fry may be treated for 60 min at ≤ 50μl/l.

  8. Acute toxicity of hydrogen peroxide treatments to selected lifestages of cold-, cool-, and warmwater fish

    USGS Publications Warehouse

    Gaikowski, M.P.; Rach, J.J.; Ramsay, R.T.

    1999-01-01

    Hatchery personnel depend on therapeutant treatments to control diseases. Currently, hatchery managers in the United States are limited to one approved therapeutant (formalin) and three compounds of Low Regulatory Priority (sodium chloride, hydrogen peroxide, and acetic acid) to control external diseases of cultured fish. Hydrogen peroxide has been used to effectively control external columnaris and bacterial gill disease in rainbow trout, however, definitive safe treatment concentrations for hydrogen peroxide are lacking for a variety of species. We report the acute toxicity of hydrogen peroxide treatments to 11 species of fry and 13 species of fingerling freshwater fish. Most mortality occurred within the first 30 h after the first exposure to hydrogen peroxide with little change in the overall shape of survival curves over time. Our data predict that in an actual therapeutic application of hydrogen peroxide, most treatment-related mortalities would be observed shortly after the initial exposure. Coolwater species were more sensitive than coldwater species but were generally similar to warmwater species tested. Based on our mortality data, coldwater species and largemouth bass may be treated for 60 min at concentrations of ??? 150 ??l/l without harmful effects; all muskellunge, walleye, bluegill, channel catfish, yellow perch, pallid sturgeon fingerlings, fathead minnow fingerlings, white sucker fingerlings, and northern pike fry may be treated for 60 min at ??? 100 ??l/l; and northern pike fingerlings and white sucker, yellow perch and fathead minnow fry may be treated for 60 min at ??? 50 ??l/l.

  9. In situ oxidation remediation technologies: kinetic of hydrogen peroxide decomposition on soil organic matter.

    PubMed

    Romero, Arturo; Santos, Aurora; Vicente, Fernando; Rodriguez, Sergio; Lafuente, A Lopez

    2009-10-30

    Rates of hydrogen peroxide decomposition were investigated in soils slurries. The interaction soil-hydrogen peroxide was studied using a slurry system at 20 degrees C and pH 7. To determine the role of soil organic matter (SOM) in the decomposition of hydrogen peroxide, several experiments were carried out with two soils with different SOM content (S1=15.1%, S2=10%). The influence of the oxidant dosage ([H2O2](o) from 10 to 30 g L(-1) and soil weight to liquid phase volume ratio=500 g L(-1)) was investigated using the two calcareous loamy sand soil samples. The results showed a rate dependency on both SOM and hydrogen peroxide concentration being the H2O2 decomposition rate over soil surface described by a second-order kinetic expression r(H2O2) = -dn(H2O2) / W(SOM) dt = kC(H2O2) C(SOM). Thermogravimetric analysis (TGA) was used to evaluate the effect caused by the application of this oxidant on the SOM content. It was found a slightly increase of SOM content after treatment with hydrogen peroxide, probably due to the incorporation of oxygen from the oxidant (hydrogen peroxide).

  10. Boronate-based fluorescent probes: imaging hydrogen peroxide in living systems.

    PubMed

    Lin, Vivian S; Dickinson, Bryan C; Chang, Christopher J

    2013-01-01

    Hydrogen peroxide, a reactive oxygen species with unique chemical properties, is produced endogenously in living systems as a destructive oxidant to ward off pathogens or as a finely tuned second messenger in dynamic cellular signaling pathways. In order to understand the complex roles that hydrogen peroxide can play in biological systems, new tools to monitor hydrogen peroxide in its native settings, with high selectivity and sensitivity, are needed. Knowledge of organic synthetic reactivity provides the foundation for the molecular design of selective, functional hydrogen peroxide probes. A palette of fluorescent and luminescent probes that react chemoselectively with hydrogen peroxide has been developed, utilizing a boronate oxidation trigger. These indicators offer a variety of colors and in cellulo characteristics and have been used to examine hydrogen peroxide in a number of experimental setups, including in vitro fluorometry, confocal fluorescence microscopy, and flow cytometry. In this chapter, we provide an overview of the chemical features of these probes and information on their behavior to help researchers select the optimal probe and application.

  11. Co-operative inhibitory effects of hydrogen peroxide and iodine against bacterial and yeast species

    PubMed Central

    2013-01-01

    Background Hydrogen peroxide and iodine are powerful antimicrobials widely used as antiseptics and disinfectants. Their antimicrobial properties are known to be enhanced by combining them with other compounds. We studied co-operative inhibitory activities (synergism, additive effects and modes of growth inhibition) of hydrogen peroxide and iodine used concurrently against 3 bacterial and 16 yeast species. Results Synergistic or additive inhibitory effects were shown for hydrogen peroxide and iodine mixtures against all 19 species used in the study. Both biocides were mostly cidal individually and in mixtures against Pseudomonas aeruginosa and Staphylococcus aureus. Both compounds manifested static inhibitory effects individually, but their mixtures were synergistically cidal for Saccharomyces cerevisiae and Escherihia coli. Cells of S. cerevisiae treated with hydrogen peroxide and iodine-hydrogen peroxide mixture produced increased numbers of respiratory deficient mutants indicating genotoxic effects. Conclusion Iodine and hydrogen peroxide used concurrently interact synergistically or additively against a range of prokaryotic and eukaryotic microorganisms. The study provides an insight as to how these traditional antimicrobials could be used more effectively for disinfection and antisepsis. In addition, a simple approach is proposed for scoring genotoxicity of different biocides by using the budding yeast system. PMID:23856115

  12. Solid state and solution 43Ca NMR of calcium peroxides involved in the disproportionation of hydrogen peroxide by calcium hydroxide.

    PubMed

    Trokiner, Arlette; Bessière, Aurélie; Thouvenot, René; Hau, Damien; Marko, Jean; Nardello, Véronique; Pierlot, Christel; Aubry, Jean-Marie

    2004-06-01

    In order to get some insight into the mechanism of the disproportionation of hydrogen peroxide catalyzed by calcium hydroxide, 43Ca NMR spectra of enriched samples of calcium peroxides and of their precursors have been studied in both solution and solid state. This study demonstrates that no well-defined peroxidized calcium species are formed in solution, showing that the catalytic role of calcium is likely restricted to the solid state. Most of the calcium compounds that could be involved in the catalytic process have been investigated with solid state NMR. The shift and quadrupolar parameters of Ca(OH)2, CaO2.8H2O and CaO2.2H2O2 are reported for the first time. These parameters are different enough to allow the quantitative analysis of a complex mixture of these compounds by NMR.

  13. Impairment of phagocytic functions of alveolar macrophages by hydrogen peroxide

    SciTech Connect

    Oosting, R.S.; van Bree, L.; van Iwaarden, J.F.; van Golde, L.M.; Verhoef, J. )

    1990-08-01

    Hydrogen peroxide (H2O2) inhibited phagocytosis and superoxide anion production by rat alveolar macrophages. The inhibition was irreversible and concentration and exposure time dependent. The potential relationship between H2O2-induced biochemical perturbations and impaired alveolar macrophage phagocytic functions was investigated. Alveolar macrophage viability and Fc receptor binding capacity were not affected by H2O2. There was probably no correlation between a H2O2-induced rise in cytosolic (Ca2+) ((Ca2+)i) and the impairment of phagocytosis by alveolar macrophages, as was suggested by the following findings. First, the H2O2-induced rise in (Ca2+)i could be inhibited by chelation of extracellular Ca2+, whereas the H2O2-induced impairment of phagocytosis could not. Second, the H2O2-induced rise in (Ca2+)i was reversible, whereas the impairment of phagocytosis was not. And finally, a rise in (Ca2+)i by incubation of alveolar macrophages with the calcium ionophore A23187 did not affect phagocytosis. Various experiments suggested that ATP depletion may play an important role in the H2O2 toxicity for alveolar macrophages. Comparable concentrations of H2O2 caused an irreversible decrease both in cellular ATP and in phagocytosis and superoxide production by alveolar macrophages. In addition, time course of ATP depletion and induction of impaired alveolar macrophage function were similar. In view of the fact that the strong oxidant H2O2 may react with a large variety of biological substances, possible other toxic lesions may not be excluded as underlying mechanism for H2O2-induced inhibition of phagocytic functions of alveolar macrophages.

  14. Modular Advanced Oxidation Process Enabled by Cathodic Hydrogen Peroxide Production

    PubMed Central

    2015-01-01

    Hydrogen peroxide (H2O2) is frequently used in combination with ultraviolet (UV) light to treat trace organic contaminants in advanced oxidation processes (AOPs). In small-scale applications, such as wellhead and point-of-entry water treatment systems, the need to maintain a stock solution of concentrated H2O2 increases the operational cost and complicates the operation of AOPs. To avoid the need for replenishing a stock solution of H2O2, a gas diffusion electrode was used to generate low concentrations of H2O2 directly in the water prior to its exposure to UV light. Following the AOP, the solution was passed through an anodic chamber to lower the solution pH and remove the residual H2O2. The effectiveness of the technology was evaluated using a suite of trace contaminants that spanned a range of reactivity with UV light and hydroxyl radical (HO•) in three different types of source waters (i.e., simulated groundwater, simulated surface water, and municipal wastewater effluent) as well as a sodium chloride solution. Irrespective of the source water, the system produced enough H2O2 to treat up to 120 L water d–1. The extent of transformation of trace organic contaminants was affected by the current density and the concentrations of HO• scavengers in the source water. The electrical energy per order (EEO) ranged from 1 to 3 kWh m–3, with the UV lamp accounting for most of the energy consumption. The gas diffusion electrode exhibited high efficiency for H2O2 production over extended periods and did not show a diminution in performance in any of the matrices. PMID:26039560

  15. Hydrogen peroxide regulated photosynthesis in C4-pepc transgenic rice.

    PubMed

    Ren, C G; Li, X; Liu, X L; Wei, X D; Dai, C C

    2014-01-01

    In this study, we investigated the photosynthetic physiological basis in 'PC' transgenic rice (Oryza sativa L.), showing high-level expression of the gene encoding C4 phosphoenolpyruvate carboxylase (pepc), by hydrogen peroxide (H2O2). The C4-PEPC gene (pepc) from maize in the transgenic rice plants was checked by PCR. Comparison of yield components and photosynthetic indices between PC and untransformed wild-type (WT) plants indicated that increased yield in PC was associated with higher net photosynthetic rate and higher activities of phosphoenolpyruvate carboxylase (PEPC). Both PC and WT plants were treated with 1 mmol L(-1) abscisic acid (ABA), 0.04% 1-butanol (BA), 2 mmol L(-1) neomycin (NS), or 2 mmol L(-1) diphenyleneiodonium chloride (DPI) to investigate the relationship between photosynthesis and levels of H2O2 and phosphatidic acid. In both PC and WT, ABA induced H2O2 generation and simultaneous decrease in stomatal conductance (g(s)). PC plants treated with BA showed decreased H2O2 content and strongly increased g(s) within 2 h of treatment. Similar results were observed in response to DPI treatment in PC. However, WT did not observe the decrease of H2O2 during the treatments of BA and DPI. The reduced H2O2 content in PC caused by BA treatment differed to that induced by DPI because BA did not inhibit NADPH oxidase activities. While BA induced a larger PEPC activity in PC, and higher catalase activity as well. These results indicated that the regulation of endogenous H2O2 metabolism of PC could be helpful for enhancing photosynthetic capability.

  16. Shock initiation studies on high concentration hydrogen peroxide

    SciTech Connect

    Sheffield, Stephen A; Dattelbaum, Dana M; Stahl, David B; Gibson, L. Lee; Bartram, Brian D.

    2009-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. TV cameras are attached to the target so the cell filling can be monitored. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; initiation has been observed in some experiments that shows homogeneous shock initiation behavior. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these measurements, we have determined unreacted Hugoniot information, times (distances) to detonation (Pop-plot points) that indicate low sensitivity, and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions that agree with earlier estimates.

  17. Modular advanced oxidation process enabled by cathodic hydrogen peroxide production.

    PubMed

    Barazesh, James M; Hennebel, Tom; Jasper, Justin T; Sedlak, David L

    2015-06-16

    Hydrogen peroxide (H2O2) is frequently used in combination with ultraviolet (UV) light to treat trace organic contaminants in advanced oxidation processes (AOPs). In small-scale applications, such as wellhead and point-of-entry water treatment systems, the need to maintain a stock solution of concentrated H2O2 increases the operational cost and complicates the operation of AOPs. To avoid the need for replenishing a stock solution of H2O2, a gas diffusion electrode was used to generate low concentrations of H2O2 directly in the water prior to its exposure to UV light. Following the AOP, the solution was passed through an anodic chamber to lower the solution pH and remove the residual H2O2. The effectiveness of the technology was evaluated using a suite of trace contaminants that spanned a range of reactivity with UV light and hydroxyl radical (HO(•)) in three different types of source waters (i.e., simulated groundwater, simulated surface water, and municipal wastewater effluent) as well as a sodium chloride solution. Irrespective of the source water, the system produced enough H2O2 to treat up to 120 L water d(-1). The extent of transformation of trace organic contaminants was affected by the current density and the concentrations of HO(•) scavengers in the source water. The electrical energy per order (EEO) ranged from 1 to 3 kWh m(-3), with the UV lamp accounting for most of the energy consumption. The gas diffusion electrode exhibited high efficiency for H2O2 production over extended periods and did not show a diminution in performance in any of the matrices.

  18. Effects of Hydrogen Peroxide on Coral Photosynthesis and Calcification

    NASA Astrophysics Data System (ADS)

    Higuchi, T.; Fujimura, H.; Arakaki, T.; Oomori, T.

    2007-12-01

    The widely-observed decline of coral reefs is considered to be caused by changes in the environment by natural and anthropogenic activities. As one important factor, the run-off of various matters from human activities to the coastal seawater poses stresses to the corals by degrading the quality of the seawater. In Okinawa, Japan, red- soil running off from the developed land has been a major environmental issue since 1980s. Hydrogen peroxide (HOOH), a strong active oxygen species, is one of the photochemically formed chemicals in the red-soil-polluted seawater. Recent photochemical studies of seawater showed that HOOH photo-formation was faster in the red- soil-polluted seawater than clean seawater. We studied the effects of HOOH on corals by studying the changes in coral carbon metabolisms such as photosynthesis and calcification, which are indicators of the physiological state of a coral colony. The corals were exposed to various concentrations of HOOH (0, 0.3, 3 μM). Two massive coral species of Porites sp. and Goniastrea aspera and one branch coral of Galaxea facicularis were used for the exposure experiments. The control experiments showed that when no HOOH was added, metabolisms of each coral colony were relatively stable. On the other hand, when HOOH was added to the seawater, we observed obvious changes in the coral metabolisms in all the coral species. When 0.3 μM HOOH was added, photosynthesis decreased by 14% and calcification decreased by 17% within 3 days, compared with the control. When 3 μM HOOH was added, photosynthesis decreased by 21% and calcification decreased by 41% within 3 days, compared with the control. Our study showed that higher concentrations of HOOH posed more stress to the coral colonies.

  19. Hydrogen peroxide induces apoptosis via a mitochondrial pathway in chondrocytes

    NASA Astrophysics Data System (ADS)

    Zhuang, Cai-ping; Liang, Qian; Wang, Xiao-ping; Chen, Tong-sheng

    2012-03-01

    The degenerative joint disease such as osteoarthritis (OA) is closely associated with the death of chondrocytes in apoptosis fashion. Hydrogen peroxide (H2O2), higher expression following acute damage in OA patients, has been shown to be up-regulated during apoptosis in a bulk of experimental models. This study was aimed to explore the mechanism of H2O2-induced rabbit chondrocytes apoptosis. Articular cartilage was biopsied from the joints of 6 weeks old New Zealand rabbits. Cell Counting Kit (CCK-8) assay was used to assess the inhibitory effect of H2O2 on cell viability. H2O2 treatment induced a remarkable reduction of cell viability. We used flow cytometry to assess the form of cell death with Annexin-V/PI double staining, and found that H2O2 treatment induced apoptosis in a dose-and time-dependent manner. Exposure of chondrocytes to 1.5 mM of H2O2 for 2 h induced a burst apoptosis that can be alleviated by N-acetyl cysteine (NAC) pretreatment, an anti-oxidant amino-acid derivative. Loss of mitochondria membrane potential (▵Ψm) was evaluated using confocal microscopy imaging and flow cytometry (FCM). H2O2 treatment induced a marked reduction of ▵Ψm, and the abrupt disappearance of ▵Ψm occurred within 5 minutes. These results indicate that H2O2 induces a rapid apoptosis via a mitochondrial pathway in rabbit chondrocytes.

  20. Modular advanced oxidation process enabled by cathodic hydrogen peroxide production.

    PubMed

    Barazesh, James M; Hennebel, Tom; Jasper, Justin T; Sedlak, David L

    2015-06-16

    Hydrogen peroxide (H2O2) is frequently used in combination with ultraviolet (UV) light to treat trace organic contaminants in advanced oxidation processes (AOPs). In small-scale applications, such as wellhead and point-of-entry water treatment systems, the need to maintain a stock solution of concentrated H2O2 increases the operational cost and complicates the operation of AOPs. To avoid the need for replenishing a stock solution of H2O2, a gas diffusion electrode was used to generate low concentrations of H2O2 directly in the water prior to its exposure to UV light. Following the AOP, the solution was passed through an anodic chamber to lower the solution pH and remove the residual H2O2. The effectiveness of the technology was evaluated using a suite of trace contaminants that spanned a range of reactivity with UV light and hydroxyl radical (HO(•)) in three different types of source waters (i.e., simulated groundwater, simulated surface water, and municipal wastewater effluent) as well as a sodium chloride solution. Irrespective of the source water, the system produced enough H2O2 to treat up to 120 L water d(-1). The extent of transformation of trace organic contaminants was affected by the current density and the concentrations of HO(•) scavengers in the source water. The electrical energy per order (EEO) ranged from 1 to 3 kWh m(-3), with the UV lamp accounting for most of the energy consumption. The gas diffusion electrode exhibited high efficiency for H2O2 production over extended periods and did not show a diminution in performance in any of the matrices. PMID:26039560

  1. Can an LED-laser hybrid light help to decrease hydrogen peroxide concentration while maintaining effectiveness in teeth bleaching?

    NASA Astrophysics Data System (ADS)

    Martín, J.; Ovies, N.; Cisternas, P.; Fernández, E.; Oliveira Junior, O. B.; de Andrade, M. F.; Moncada, G.; Vildósola, P.

    2015-02-01

    The aim of this study was to compare the bleaching efficacy of 35% hydrogen peroxide and 15% hydrogen peroxide with nitrogen-doped titanium dioxide catalysed by an LED-laser hybrid light. We studied 70 patients randomized to two groups. Tooth shade and pulpal sensitivity were registered. Group 1: 15% hydrogen peroxide with nitrogen-doped titanium dioxide. Group 2: 35% hydrogen peroxide. Both groups were activated by an LED-laser light. No significant differences were seen in shade change immediately, one week or one month after treatment (p > 0.05). Differences were seen in pulpal sensitivity (p < 0.05). The use of an LED-laser hybrid light to activate 15% hydrogen peroxide gel with N_TiO2 permits decreasing the peroxide concentration with similar aesthetic results and less pulpal sensitivity than using 35% hydrogen peroxide for bleaching teeth.

  2. Considerations for Storage of High Test Hydrogen Peroxide (HTP) Utilizing Non-Metal Containers

    NASA Technical Reports Server (NTRS)

    Moore, Robin E.; Scott, Joseph P.; Wise, Harry

    2005-01-01

    When working with high concentrations of hydrogen peroxide, it is critical that the storage container be constructed of the proper materials, those which will not degrade to the extent that container breakdown or dangerous decomposition occurs. It has been suggested that the only materials that will safely contain the peroxide for a significant period of time are metals of stainless steel construction or aluminum use as High Test Hydrogen Peroxide (HTP) Containers. The stability and decomposition of HTP will be also discussed as well as various means suggested in the literature to minimize these problems. The dangers of excess oxygen generation are also touched upon.

  3. Reduction of hydrogen peroxide-induced erythrocyte damage by Carica papaya leaf extract

    PubMed Central

    Okoko, Tebekeme; Ere, Diepreye

    2012-01-01

    Objective To investigate the in vitro antioxidant potential of Carica papaya (C. papaya) leaf extract and its effect on hydrogen peroxide-induced erythrocyte damage assessed by haemolysis and lipid peroxidation. Methods Hydroxyl radical scavenging activities, hydrogen ion scavenging activity, metal chelating activity, and the ferrous ion reducing ability were assessed as antioxidant indices. In the other experiment, human erythrocytes were treated with hydrogen peroxide to induce erythrocyte damage. The extract (at various concentrations) was subsequently incubated with the erythrocytes and later analysed for haemolysis and lipid peroxidation as indices for erythrocyte damage. Results Preliminary investigation of the extract showed that the leaf possessed significant antioxidant and free radical scavenging abilities using in vitro models in a concentration dependent manner (P<0.05). The extract also reduced hydrogen peroxide induced erythrocyte haemolysis and lipid peroxidation significantly when compared with ascorbic acid (P<0.05). The IC50 values were 7.33 mg/mL and 1.58 mg/mL for inhibition of haemolysis and lipid peroxidation, respectively. In all cases, ascorbic acid (the reference antioxidant) possessed higher activity than the extract. Conclusions The findings show that C. papaya leaves possess significant bioactive potential which is attributed to the phytochemicals which act in synergy. Thus, the leaves can be exploited for pharmaceutical and nutritional purposes. PMID:23569948

  4. Zinc dioxide nanoparticulates: a hydrogen peroxide source at moderate pH.

    PubMed

    Wolanov, Yitzhak; Prikhodchenko, Petr V; Medvedev, Alexander G; Pedahzur, Rami; Lev, Ovadia

    2013-08-01

    Solid peroxides are a convenient source of hydrogen peroxide, which once released can be readily converted to active oxygen species or to dissolved dioxygen. A zinc peroxide nanodispersion was synthesized and characterized, and its solubility was determined as a function of pH and temperature. We show that zinc peroxide is much more stable in aqueous solutions compared to calcium and magnesium peroxides and that it retains its peroxide content down to pH 6. At low pH conditions H2O2 release is thermodynamically controlled and its dissolution product, Zn(2+), is highly soluble, and thus, hydrogen peroxide release can be highly predictable. The Gibbs free energy of formation of zinc peroxide was found to be -242.0 ± 0.4 kJ/mol and the enthalpy of formation was -292.1 ± 0.7 kJ/mol, substantially higher than theoretically predicted before. The biocidal activity of zinc peroxide was determined by inactivation studies with Escherichia coli cultures, and the activity trend agrees well with the thermodynamic predictions. PMID:23829468

  5. Zinc dioxide nanoparticulates: a hydrogen peroxide source at moderate pH.

    PubMed

    Wolanov, Yitzhak; Prikhodchenko, Petr V; Medvedev, Alexander G; Pedahzur, Rami; Lev, Ovadia

    2013-08-01

    Solid peroxides are a convenient source of hydrogen peroxide, which once released can be readily converted to active oxygen species or to dissolved dioxygen. A zinc peroxide nanodispersion was synthesized and characterized, and its solubility was determined as a function of pH and temperature. We show that zinc peroxide is much more stable in aqueous solutions compared to calcium and magnesium peroxides and that it retains its peroxide content down to pH 6. At low pH conditions H2O2 release is thermodynamically controlled and its dissolution product, Zn(2+), is highly soluble, and thus, hydrogen peroxide release can be highly predictable. The Gibbs free energy of formation of zinc peroxide was found to be -242.0 ± 0.4 kJ/mol and the enthalpy of formation was -292.1 ± 0.7 kJ/mol, substantially higher than theoretically predicted before. The biocidal activity of zinc peroxide was determined by inactivation studies with Escherichia coli cultures, and the activity trend agrees well with the thermodynamic predictions.

  6. Replacement of hydrogen peroxide cleaning with oxygen plasma

    NASA Astrophysics Data System (ADS)

    Adams, B. E.

    1992-03-01

    Comparison between the standard peroxide cleaning method and an oxygen plasma modified version was run on thin film bond monitors. The plasma modified version substituted oxygen plasma for the peroxide cleaning step in the process and reduced the DI rinse water temperature from 75 C to 25 C. A direct surface cleanliness comparison was made between the two cleaning methods using Auger spectroscopy. A beam lead and ribbon bonding experiment was also run on plasma-cleaned networks. Results of both experiments indicate that plasma cleaning is superior to peroxide cleaning and that reliable bonding can be done on plasma-cleaned thin film networks.

  7. Hydrogen peroxide stimulates cell motile activity through LPA receptor-3 in liver epithelial WB-F344 cells

    SciTech Connect

    Shibata, Ayano; Tanabe, Eriko; Inoue, Serina; Kitayoshi, Misaho; Okimoto, Souta; Hirane, Miku; Araki, Mutsumi; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2013-04-12

    Highlights: •Hydrogen peroxide stimulates cell motility of WB-F344 cells. •LPA{sub 3} is induced by hydrogen peroxide in WB-F344 cells. •Cell motility by hydrogen peroxide is inhibited in LPA{sub 3} knockdown cells. •LPA signaling is involved in cell migration by hydrogen peroxide. -- Abstract: Hydrogen peroxide which is one of reactive oxygen species (ROS) mediates a variety of biological responses, including cell proliferation and migration. In the present study, we investigated whether lysophosphatidic acid (LPA) signaling is involved in cell motile activity stimulated by hydrogen peroxide. The rat liver epithelial WB-F344 cells were treated with hydrogen peroxide at 0.1 or 1 μM for 48 h. In cell motility assays, hydrogen peroxide treated cells showed significantly high cell motile activity, compared with untreated cells. To measure the expression levels of LPA receptor genes, quantitative real time RT-PCR analysis was performed. The expressions of LPA receptor-3 (Lpar3) in hydrogen peroxide treated cells were significantly higher than those in control cells, but not Lpar1 and Lpar2 genes. Next, to assess the effect of LPA{sub 3} on cell motile activity, the Lpar3 knockdown cells from WB-F344 cells were also treated with hydrogen peroxide. The cell motile activity of the knockdown cells was not stimulated by hydrogen peroxide. Moreover, in liver cancer cells, hydrogen peroxide significantly activated cell motility of Lpar3-expressing cells, but not Lpar3-unexpressing cells. These results suggest that LPA signaling via LPA{sub 3} may be mainly involved in cell motile activity of WB-F344 cells stimulated by hydrogen peroxide.

  8. Trends in Selective Hydrogen Peroxide Production on Transition Metal Surfaces from First Principles

    SciTech Connect

    Rankin, Rees B.; Greeley, Jeffrey P.

    2012-10-19

    We present a comprehensive, Density Functional Theory-based analysis of the direct synthesis of hydrogen peroxide, H2O2, on twelve transition metal surfaces. We determine the full thermodynamics and selected kinetics of the reaction network on these metals, and we analyze these energetics with simple, microkinetically motivated rate theories to assess the activity and selectivity of hydrogen peroxide production on the surfaces of interest. By further exploiting Brønsted-Evans-Polanyi relationships and scaling relationships between the binding energies of different adsorbates, we express the results in the form of a two dimensional contour volcano plot, with the activity and selectivity being determined as functions of two independent descriptors, the atomic hydrogen and oxygen adsorption free energies. We identify both a region of maximum predicted catalytic activity, which is near Pt and Pd in descriptor space, and a region of selective hydrogen peroxide production, which includes Au. The optimal catalysts represent a compromise between activity and selectivity and are predicted to fall approximately between Au and Pd in descriptor space, providing a compact explanation for the experimentally known performance of Au-Pd alloys for hydrogen peroxide synthesis, and suggesting a target for future computational screening efforts to identify improved direct hydrogen peroxide synthesis catalysts. Related methods of combining activity and selectivity analysis into a single volcano plot may be applicable to, and useful for, other aqueous phase heterogeneous catalytic reactions where selectivity is a key catalytic criterion.

  9. Hydrogen peroxide sensing, signaling and regulation of transcription factors

    PubMed Central

    Marinho, H. Susana; Real, Carla; Cyrne, Luísa; Soares, Helena; Antunes, Fernando

    2014-01-01

    The regulatory mechanisms by which hydrogen peroxide (H2O2) modulates the activity of transcription factors in bacteria (OxyR and PerR), lower eukaryotes (Yap1, Maf1, Hsf1 and Msn2/4) and mammalian cells (AP-1, NRF2, CREB, HSF1, HIF-1, TP53, NF-κB, NOTCH, SP1 and SCREB-1) are reviewed. The complexity of regulatory networks increases throughout the phylogenetic tree, reaching a high level of complexity in mammalians. Multiple H2O2 sensors and pathways are triggered converging in the regulation of transcription factors at several levels: (1) synthesis of the transcription factor by upregulating transcription or increasing both mRNA stability and translation; (ii) stability of the transcription factor by decreasing its association with the ubiquitin E3 ligase complex or by inhibiting this complex; (iii) cytoplasm–nuclear traffic by exposing/masking nuclear localization signals, or by releasing the transcription factor from partners or from membrane anchors; and (iv) DNA binding and nuclear transactivation by modulating transcription factor affinity towards DNA, co-activators or repressors, and by targeting specific regions of chromatin to activate individual genes. We also discuss how H2O2 biological specificity results from diverse thiol protein sensors, with different reactivity of their sulfhydryl groups towards H2O2, being activated by different concentrations and times of exposure to H2O2. The specific regulation of local H2O2 concentrations is also crucial and results from H2O2 localized production and removal controlled by signals. Finally, we formulate equations to extract from typical experiments quantitative data concerning H2O2 reactivity with sensor molecules. Rate constants of 140 M−1 s−1 and ≥1.3 × 103 M−1 s−1 were estimated, respectively, for the reaction of H2O2 with KEAP1 and with an unknown target that mediates NRF2 protein synthesis. In conclusion, the multitude of H2O2 targets and mechanisms provides an opportunity for highly

  10. Responses of rabbit pulmonary arteries to hydrogen peroxide

    SciTech Connect

    Russell, J.A.; Gugino, S.F.; Giese, E.C. )

    1991-03-15

    The effects of hydrogen peroxide on isolated rabbit intrapulmonary arteries were investigated using tissue bath techniques. Exposure of resting vessels to 10{sup {minus}7}-10{sup {minus}5} M H{sub 2}O{sub 2} caused concentration-dependent contractions that were blocked by 10{sup {minus}5} M indomethacin, 3 {times} 10{sup {minus}6} M SQ 29548 or by removal of the endothelium. Addition of a single concentration of H{sub 2}O{sub 2} to resting vessels incubated with 3 {times} 10{sup {minus}6} M SQ 29548 caused slowly developing contractions that attained approximately 80% of the response to 118mM KCL. Late phase contractions were highly resistance to the inhibitory effects of 10{sup {minus}8}-10{sup {minus}5} M isoproterenol or 10{sup {minus}7}-10{sup {minus}5} M sodium nitroprusside and they persisted in calcium-free media, in vessels incubated with 5 {times} 10{sup {minus}5} M verapamil, and after removal of the endothelium. Pulmonary arteries incubated with 3 {times} 10{sup {minus}6} M SQ 29548 and contracted by 10{sup {minus}7} M phenylephrine relaxed in response to 10{sup {minus}7}-10{sup {minus}5} M H{sub 2}O{sub 2}. H{sub 2}O{sub 2}-induced relaxations were unaffected by 10{sup {minus}4} M N{omega}-nitro-L-arginine or 10{sup {minus}5}M indomethacin but were partially depressed by removal of the endothelium. The authors conclude that H{sub 2}O{sub 2} causes: an early phase contraction via release of thromboxane A2 from endothelial cells; a late-phase contraction that is endothelium-independent and probably results from the release of calcium from intracellular stores in smooth muscle cells; and an early phase relaxation that may be due to both endothelium-dependent and endothelium-independent mechanisms. The endothelium-derived relaxing factor does not appear to be nitric oxide or a dilator prostaglandin.

  11. Prediction of Severe Neonatal Hyperbilirubinemia Using Cord Blood Hydrogen Peroxide: A Prospective Study

    PubMed Central

    Chou, Hung-Chieh; Chien, Chiang-Ting; Tsao, Po-Nien; Hsieh, Wu-Shiun; Chen, Chien-Yi; Chang, Mei-Hwei

    2014-01-01

    Background We hypothesized that cord blood hydrogen peroxide (H2O2) could be utilized to predict the severity of neonatal hyperbilirubinemia. Methods We prospectively enrolled term or near-term healthy neonates. Cord blood and capillary blood at three days of age were measured for hydrogen peroxide and bilirubin concentrations. For newborns with hyperbilirubinemia, further blood samples were obtained at five and seven days of age. Newborns were divided into severe or less severe hyperbilirubinemic groups (peak bilirubin ≥17 mg/dL or not). The sensitivity, specificity, and negative predictive values were determined. Results There were 158 neonates enrolled. The incidence of neonatal hyperbilirubinemia was 30.5% for a concentration ≥15 mg/dl. The rising patterns were similar among bilirubin concentrations and hydrogen peroxide levels during the first few days of life. There was a strong positive correlation between bilirubin concentrations and hydrogen peroxide levels after correlation analysis. The rate of severe hyperbilirubinemia was 13.3%. It revealed that a cord blood hydrogen peroxide signal level of 2500 counts/10 seconds was an appropriate cut-off for predicting severe hyperbilirubinemia. Sensitivity and the negative predictive value were 76.2% and 93.3%, respectively. Conclusions Our findings confirm that hydrogen peroxide levels and bilirubin concentrations in cord and neonatal blood are closely related. A cord blood hydrogen peroxide level above 2500 counts/10 seconds associated with a high predictive value for severe hyperbilirubinemia. This method provides information about which neonate should be closely followed after discharge from the nursery. PMID:24466244

  12. Protection against hydrogen peroxide induced oxidative damage in rat erythrocytes by Mangifera indica L. peel extract.

    PubMed

    Ajila, C M; Prasada Rao, U J S

    2008-01-01

    Phytochemicals such as polyphenols and carotenoids are gaining importance because of their contribution to human health and their multiple biological effects such as antioxidant, antimutagenic, anticarcinogenic and cytoprotective activities and other therapeutic properties. Mango peel is a major by-product in pulp industry and it contains various bioactive compounds like polyphenols, carotenoids and others. In the present study, the protective effect of peel extracts of unripe and ripe mango fruits of two varieties namely, Raspuri and Badami on hydrogen peroxide induced hemolysis, lipid peroxidation, degradation of membrane proteins and its morphological changes are reported. The oxidative hemolysis of rat erythrocytes by hydrogen peroxide was inhibited by mango peel extract in a dose dependent manner. The IC(50) value for lipid peroxidation inhibition on erythrocyte ghost membrane was found to be in the range of 4.5-19.3 microg gallic acid equivalents. The mango peel extract showed protection against membrane protein degradation caused by hydrogen peroxide. Morphological changes to erythrocyte membrane caused by hydrogen peroxide were protected by mango peel extract. The results demonstrated that mango peel extracts protected erythrocytes against oxidative stress and may impart health benefits and it could be used as a valuable food ingredient or a nutraceutical product.

  13. Studies of Paroxysmal Nocturnal Hemoglobinuria Erythrocytes: Increased Lysis and Lipid Peroxide Formation by Hydrogen Peroxide*

    PubMed Central

    Mengel, Charles E.; Kann, Herbert E.; Meriwether, Wilhelm D.

    1967-01-01

    When paroxysmal nocturnal hemoglobinuria (PNH) erythrocytes were exposed to H2O2 they lysed excessively and formed greater than normal quantities of lipid peroxides when compared to red cells of normal subjects and patients with most types of hematologic disease. It was also shown that lytic sensitivity to acidified serum was related to the enhanced lytic sensitivity to H2O2. If the lipid of PNH cells was first extracted then exposed to ultraviolet radiation more lipid peroxides were formed than in extracts of normal red blood cells. The possible explanations for these findings and their relationship to the PNH hemolytic mechanism are discussed. Images PMID:6061745

  14. Hydrogen Peroxide and Polyamines Act as Double Edged Swords in Plant Abiotic Stress Responses.

    PubMed

    Gupta, Kamala; Sengupta, Atreyee; Chakraborty, Mayukh; Gupta, Bhaskar

    2016-01-01

    The specific genetic changes through which plants adapt to the multitude of environmental stresses are possible because of the molecular regulations in the system. These intricate regulatory mechanisms once unveiled will surely raise interesting questions. Polyamines and hydrogen peroxide have been suggested to be important signaling molecules during biotic and abiotic stresses. Hydrogen peroxide plays a versatile role from orchestrating physiological processes to stress response. It helps to achieve acclimatization and tolerance to stress by coordinating intra-cellular and systemic signaling systems. Polyamines, on the other hand, are low molecular weight polycationic aliphatic amines, which have been implicated in various stress responses. It is quite interesting to note that both hydrogen peroxide and polyamines have a fine line of inter-relation between them since the catabolic pathways of the latter releases hydrogen peroxide. In this review we have tried to illustrate the roles and their multifaceted functions of these two important signaling molecules based on current literature. This review also highlights the fact that over accumulation of hydrogen peroxide and polyamines can be detrimental for plant cells leading to toxicity and pre-mature cell death. PMID:27672389

  15. Evaluation of the biological efficacy of hydrogen peroxide vapour decontamination in wards of an Australian hospital.

    PubMed

    Chan, H-T; White, P; Sheorey, H; Cocks, J; Waters, M-J

    2011-10-01

    This study assessed the efficacy of a 'dry' hydrogen peroxide vapour decontamination in an Australian hospital via a two-armed study. The in vivo arm examined the baseline bacterial counts in high-touch zones within wards and evaluated the efficacy of cleaning with a neutral detergent followed by either hydrogen peroxide vapour decontamination, or a manual terminal clean with bleach or Det-Sol 500. The in vitro arm examined the efficacy of hydrogen peroxide vapour decontamination on a variety of different surfaces commonly found in the wards of an Australian hospital, deliberately seeded with a known concentration of vancomycin-resistant enterococci (VRE). All bacterial counts were evaluated by a protocol of contact plate method. In the in vivo arm, 33.3% of the high-touch areas assessed had aerobic bacterial count below the detection limit (i.e. no bacteria recoverable) post hydrogen peroxide decontamination, and in all circumstances the highest microbial density was ≤3 cfu/cm(2), while in the in vitro arm there was at least a reduction in bacterial load by a factor of 10 at all surfaces investigated. These results showed that dry hydrogen peroxide vapour room decontamination is highly effective on a range of surfaces, although the cleanliness data obtained by these methods cannot be easily compared among the different surfaces as recovery of organisms is affected by the nature of the surface.

  16. Hydrogen Peroxide and Polyamines Act as Double Edged Swords in Plant Abiotic Stress Responses.

    PubMed

    Gupta, Kamala; Sengupta, Atreyee; Chakraborty, Mayukh; Gupta, Bhaskar

    2016-01-01

    The specific genetic changes through which plants adapt to the multitude of environmental stresses are possible because of the molecular regulations in the system. These intricate regulatory mechanisms once unveiled will surely raise interesting questions. Polyamines and hydrogen peroxide have been suggested to be important signaling molecules during biotic and abiotic stresses. Hydrogen peroxide plays a versatile role from orchestrating physiological processes to stress response. It helps to achieve acclimatization and tolerance to stress by coordinating intra-cellular and systemic signaling systems. Polyamines, on the other hand, are low molecular weight polycationic aliphatic amines, which have been implicated in various stress responses. It is quite interesting to note that both hydrogen peroxide and polyamines have a fine line of inter-relation between them since the catabolic pathways of the latter releases hydrogen peroxide. In this review we have tried to illustrate the roles and their multifaceted functions of these two important signaling molecules based on current literature. This review also highlights the fact that over accumulation of hydrogen peroxide and polyamines can be detrimental for plant cells leading to toxicity and pre-mature cell death.

  17. Low Concentrations of Hydrogen Peroxide Activate the Antioxidant Defense System in Human Sperm Cells.

    PubMed

    Evdokimov, V V; Barinova, K V; Turovetskii, V B; Muronetz, V I; Schmalhausen, E V

    2015-09-01

    The effect of low concentrations of hydrogen peroxide (10-100 µM) on sperm motility and on the activity of the sperm enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDS) was investigated. Incubation of semen samples with 10 and 100 µM hydrogen peroxide increased the content of spermatozoa with progressive motility by 20 and 18%, respectively, and enhanced the activity of GAPDS in the sperm cells by 27 and 20% compared to a semen sample incubated without additions. It was also found that incubation with 10 µM hydrogen peroxide increased the content of reduced glutathione (GSH) in sperm cells by 50% on average compared to that in the control samples. It is supposed that low concentrations of hydrogen peroxide activate the pentose phosphate pathway, resulting in NADPH synthesis and the reduction of the oxidized glutathione by glutathione reductase yielding GSH. The formed GSH reduces the oxidized cysteine residues of the GAPDS active site, increasing the activity of the enzyme, which in turn enhances the content of sperm cells with progressive motility. Thus, the increase in motile spermatozoa in the presence of low concentrations of hydrogen peroxide can serve as an indicator of normal functioning of the antioxidant defense system in sperm cells.

  18. Hydrogen Peroxide and Polyamines Act as Double Edged Swords in Plant Abiotic Stress Responses

    PubMed Central

    Gupta, Kamala; Sengupta, Atreyee; Chakraborty, Mayukh; Gupta, Bhaskar

    2016-01-01

    The specific genetic changes through which plants adapt to the multitude of environmental stresses are possible because of the molecular regulations in the system. These intricate regulatory mechanisms once unveiled will surely raise interesting questions. Polyamines and hydrogen peroxide have been suggested to be important signaling molecules during biotic and abiotic stresses. Hydrogen peroxide plays a versatile role from orchestrating physiological processes to stress response. It helps to achieve acclimatization and tolerance to stress by coordinating intra-cellular and systemic signaling systems. Polyamines, on the other hand, are low molecular weight polycationic aliphatic amines, which have been implicated in various stress responses. It is quite interesting to note that both hydrogen peroxide and polyamines have a fine line of inter-relation between them since the catabolic pathways of the latter releases hydrogen peroxide. In this review we have tried to illustrate the roles and their multifaceted functions of these two important signaling molecules based on current literature. This review also highlights the fact that over accumulation of hydrogen peroxide and polyamines can be detrimental for plant cells leading to toxicity and pre-mature cell death.

  19. Light and hydrogen peroxide inhibit C. elegans Feeding through gustatory receptor orthologs and pharyngeal neurons.

    PubMed

    Bhatla, Nikhil; Horvitz, H Robert

    2015-02-18

    While gustatory sensing of the five primary flavors (sweet, salty, sour, bitter, and savory) has been extensively studied, pathways that detect non-canonical taste stimuli remain relatively unexplored. In particular, while reactive oxygen species cause generalized damage to biological systems, no gustatory mechanism to prevent ingestion of such material has been identified in any organism. We observed that light inhibits C. elegans feeding and used light as a tool to uncover molecular and neural mechanisms for gustation. Light can generate hydrogen peroxide, and we discovered that hydrogen peroxide similarly inhibits feeding. The gustatory receptor family members LITE-1 and GUR-3 are required for the inhibition of feeding by light and hydrogen peroxide. The I2 pharyngeal neurons increase calcium in response to light and hydrogen peroxide, and these responses require GUR-3 and a conserved antioxidant enzyme peroxiredoxin PRDX-2. Our results demonstrate a gustatory mechanism that mediates the detection and blocks ingestion of a non-canonical taste stimulus, hydrogen peroxide.

  20. Electrosynthesis of hydrogen peroxide via the reduction of oxygen assisted by power ultrasound.

    PubMed

    González-García, José; Banks, Craig E; Sljukić, Biljana; Compton, Richard G

    2007-04-01

    The electrosynthesis of hydrogen peroxide using the oxygen reduction reaction has been studied in the absence and presence of power ultrasound in a non-optimized sono-electrochemical flow reactor (20 cm cathodic compartment length with 6.5 cm inner diameter) with reticulated vitreous glassy carbon electrode (30 x 40 x 10 mm, 10 ppi, 7 cm(2)cm(-3)) as the cathode. The effect of several electrochemical operational variables (pH, volumetric flow, potential) and of the sono-electrochemical parameters (ultrasound amplitude and horn-to-electrode distance) on the cumulative concentration of hydrogen peroxide and current efficiency of the electrosynthesis process have been explored. The application of power ultrasound was found to increase both the cumulative concentration of hydrogen peroxide and the current efficiency. The application of ultrasound is therefore a promising approach to the increased efficiency of production of hydrogen peroxide by electrosynthesis, even in the solutions of lower pH (<12). The results demonstrate the feasibility of at-site-of-use green synthesis of hydrogen peroxide.

  1. The hydrogen peroxide impact on larval settlement and metamorphosis of abalone Haliotis diversicolor supertexta

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangjing; Yang, Zhihui; Cai, Zhonghua

    2008-08-01

    Abalone Haliotis diversicolor supertexta is an important economic mollusk. The settlement and metamorphosis are two critical stages during its development period, which has direct influence on abalone survival and production. The influence of reactive oxygen species (hydrogen peroxide) on abalone embryo and juvenile development were examined in this study. Larvae of Haliotis diversicolor supertexta were induced to settlement and metamorphose by exposure to seawater supplemented with hydrogen peroxide. They had the best performance at 800 μmol/L. The concentration of 1 000 μmol/L or higher was toxic to the larvae, as the larvae could settle down only at benthic diatom plates without complete metamorphosis. In addition, H2O2 adding time was critical to the larval performance. 24h after two-day post-fertilization was proved to be the optimal adding time. In this paper, two action mechanisms of hydrogen peroxide are discussed: (1) hydrogen peroxide has direct toxicity to ciliated cells, thus cause apoptosis; (2) hydrogen peroxide, as a product from catecholamines’ autoxidation process in vivo, can reverse this process to produce neuro-transmitters to induce abalone metamorphosis.

  2. Hydrogen Peroxide and Polyamines Act as Double Edged Swords in Plant Abiotic Stress Responses

    PubMed Central

    Gupta, Kamala; Sengupta, Atreyee; Chakraborty, Mayukh; Gupta, Bhaskar

    2016-01-01

    The specific genetic changes through which plants adapt to the multitude of environmental stresses are possible because of the molecular regulations in the system. These intricate regulatory mechanisms once unveiled will surely raise interesting questions. Polyamines and hydrogen peroxide have been suggested to be important signaling molecules during biotic and abiotic stresses. Hydrogen peroxide plays a versatile role from orchestrating physiological processes to stress response. It helps to achieve acclimatization and tolerance to stress by coordinating intra-cellular and systemic signaling systems. Polyamines, on the other hand, are low molecular weight polycationic aliphatic amines, which have been implicated in various stress responses. It is quite interesting to note that both hydrogen peroxide and polyamines have a fine line of inter-relation between them since the catabolic pathways of the latter releases hydrogen peroxide. In this review we have tried to illustrate the roles and their multifaceted functions of these two important signaling molecules based on current literature. This review also highlights the fact that over accumulation of hydrogen peroxide and polyamines can be detrimental for plant cells leading to toxicity and pre-mature cell death. PMID:27672389

  3. Determination of berberine in pharmaceutical preparations using acidic hydrogen peroxide-nitrite chemiluminescence system.

    PubMed

    Liang, Yao-Dong; Yu, Chun-Xia

    2013-03-01

    A stronger chemiluminescence (CL) was observed when hydrogen peroxide was mixed with nitrite and berberine in sulfuric acid solution. The stronger CL originated from peroxidation of berberine by peroxynitrous acid that was synthesized online by the mixing of acidic hydrogen peroxide solution with nitrite solution in a flow system. The emitting species was excited state oxyberberine, a peroxidized product of berberine. Based on the stronger CL, a flow injection CL method for the determination of berberine was proposed. Under optimum experimental conditions, the stronger CL intensity was linearly related to the concentration of berberine over the range of 2.0 × 10(-7) -2.0 × 10(-5) mol L(-1) . The limit of detection (s/n = 3) was 6.2 × 10(-8) mol L(-1) . The proposed method has been evaluated by analyzing berberine in pharmaceutical preparations.

  4. A highly sensitive hydrogen peroxide sensor based on (Ag-Au NPs)/poly[o-phenylenediamine] modified glassy carbon electrode.

    PubMed

    Shamsipur, Mojtaba; Karimi, Ziba; Amouzadeh Tabrizi, Mahmoud

    2015-11-01

    Herein, the poly(o-phenylenediamine) decorated with gold-silver nanoparticle (Ag-Au NPs) nanocomposite modified glassy carbon was used for the determination of hydrogen peroxide. Electrochemical experiments indicated that the proposed sensor possesses an excellent sensitivity toward the reduction of hydrogen peroxide. The resulting sensor exhibited a good response to hydrogen peroxide over linear range from 0.2 to 60.0μM with a limit of detection of 0.08μM, good reproducibility, long-term stability and negligible interference from ascorbic acid, uric acid and dopamine. The proposed sensor was successfully applied to the determination of hydrogen peroxide in human serum sample.

  5. How Hydrogen Peroxide Is Metabolized by Oxidized Cytochrome c Oxidase

    PubMed Central

    2015-01-01

    In the absence of external electron donors, oxidized bovine cytochrome c oxidase (CcO) exhibits the ability to decompose excess H2O2. Depending on the concentration of peroxide, two mechanisms of degradation were identified. At submillimolar peroxide concentrations, decomposition proceeds with virtually no production of superoxide and oxygen. In contrast, in the millimolar H2O2 concentration range, CcO generates superoxide from peroxide. At submillimolar concentrations, the decomposition of H2O2 occurs at least at two sites. One is the catalytic heme a3–CuB center where H2O2 is reduced to water. During the interaction of the enzyme with H2O2, this center cycles back to oxidized CcO via the intermediate presence of two oxoferryl states. We show that at pH 8.0 two molecules of H2O2 react with the catalytic center accomplishing one cycle. In addition, the reactions at the heme a3–CuB center generate the surface-exposed lipid-based radical(s) that participates in the decomposition of peroxide. It is also found that the irreversible decline of the catalytic activity of the enzyme treated with submillimolar H2O2 concentrations results specifically from the decrease in the rate of electron transfer from heme a to the heme a3–CuB center during the reductive phase of the catalytic cycle. The rates of electron transfer from ferrocytochrome c to heme a and the kinetics of the oxidation of the fully reduced CcO with O2 were not affected in the peroxide-modified CcO. PMID:24840065

  6. How hydrogen peroxide is metabolized by oxidized cytochrome c oxidase.

    PubMed

    Jancura, Daniel; Stanicova, Jana; Palmer, Graham; Fabian, Marian

    2014-06-10

    In the absence of external electron donors, oxidized bovine cytochrome c oxidase (CcO) exhibits the ability to decompose excess H2O2. Depending on the concentration of peroxide, two mechanisms of degradation were identified. At submillimolar peroxide concentrations, decomposition proceeds with virtually no production of superoxide and oxygen. In contrast, in the millimolar H2O2 concentration range, CcO generates superoxide from peroxide. At submillimolar concentrations, the decomposition of H2O2 occurs at least at two sites. One is the catalytic heme a3-CuB center where H2O2 is reduced to water. During the interaction of the enzyme with H2O2, this center cycles back to oxidized CcO via the intermediate presence of two oxoferryl states. We show that at pH 8.0 two molecules of H2O2 react with the catalytic center accomplishing one cycle. In addition, the reactions at the heme a3-CuB center generate the surface-exposed lipid-based radical(s) that participates in the decomposition of peroxide. It is also found that the irreversible decline of the catalytic activity of the enzyme treated with submillimolar H2O2 concentrations results specifically from the decrease in the rate of electron transfer from heme a to the heme a3-CuB center during the reductive phase of the catalytic cycle. The rates of electron transfer from ferrocytochrome c to heme a and the kinetics of the oxidation of the fully reduced CcO with O2 were not affected in the peroxide-modified CcO.

  7. [Continuous Generation of Hydrogen Peroxide in Water Containing Very Low Concentrations of Unsymmetrical Dimethylhydrazine].

    PubMed

    Bruskov, V I; Yaguzhinsky, L S; Masalimov, Z K; Chernikov, A V; Emelyanenko, V I; Gudkov, S V

    2015-01-01

    Continuous generation of hydrogen peroxide catalyzed by low concentrations of 1,1-dimethylhydrazine (heptyl)--a rocket fuel component--in air saturated water was shown by the method of enhanced chemiluminescence in the system of luminol-p-iodophenol-peroxidase. The concentration dependence and the influence of heat and light on the formation of hydrogen peroxide in the water under the influence of dimethylhydrazine at concentrations considerably lower than maximum allowable concentrations were studied, and the physical-chemical mechanism of this process was considered. It is supposed that dimethylhydrazine at ultra-low concentrations is associated with air nanobubbles and represents a long-lived complex performing catalysis of hydrogen peroxide formation under the influence of heat and light. We put forward the new concept of.toxicity of dimethylhydrazine at very low concentrations due to violation of homeostasis of reactive oxygen species formation in aqueous solutions entering the body of humans and animals.

  8. Microwave-assisted oxidative digestion of lignin with hydrogen peroxide for TOC and color removal.

    PubMed

    Ouyang, Xinping; Huang, Xiangzhen; Ruan, Tao; Qiu, Xueqing

    2015-01-01

    Dilute lignin solution was successfully digested into colorless and clarified liquor under microwave-assisted oxidative digestion with hydrogen peroxide. High dosage of hydrogen peroxide is needed to effectively digest lignin, but excessive hydrogen peroxide may lead to recondensation of formed fragments in digested lignin. Microwave irradiation greatly facilitates the oxidative digestion of lignin. Compared with conventional heating technique, microwave-assisted digestion achieves the same or higher digestion rate within a shorter time and/or at lower temperature. After digestion, total organic carbon content of lignin solution decreases by 93.9%, and a small amount of aliphatic alkane, alcohol, acid and ester are formed via the cleavage of aromatic rings as well as the deprivation of side chains in original lignin. This work provides an alternative way to efficiently treat spent pulping liquor. PMID:25714638

  9. Photopatternable and photoactive hydrogel for on-demand generation of hydrogen peroxide in cell culture.

    PubMed

    Garland, Shaun P; Wang, Royal Y; Raghunathan, Vijay Krishna; Lam, Kit S; Murphy, Christopher J; Russell, Paul; Sun, Gang; Pan, Tingrui

    2014-02-01

    Oxidative stress, largely mediated by reactive oxygen species (ROS), is a nearly ubiquitous component in complex biological processes such as aging and disease. Optimal in vitro methods used in elucidating disease mechanisms would deliver of low levels of hydrogen peroxide, emulating the in vivo pathological state, but current methods are limited by kinetic stability or accurate measurement of the dose administered. Here we present an in vitro platform that exploits anthraquinone catalysts for the photocatalytic production of hydrogen peroxide. This system can be dynamically tuned to provide constant generation of hydrogen peroxide at a desired physiologic rate over at least 14 days and is described using a kinetic model. Material characterization and stability is discussed along with a proof-of-concept in vitro study that assessed the viability of cells as they were oxidatively challenged over 24 h at different ROS generation rates.

  10. Gold-platinum alloy nanowires as highly sensitive materials for electrochemical detection of hydrogen peroxide.

    PubMed

    Zhou, Yibo; Yu, Gang; Chang, Fangfang; Hu, Bonian; Zhong, Chuan-Jian

    2012-12-13

    The exploitation of the unique electrical properties of nanowires requires an effective assembly of nanowires as functional materials on a signal transduction platform. This paper describes a new strategy to assemble gold-platinum alloy nanowires on microelectrode devices and demonstrates the sensing characteristics to hydrogen peroxide. The alloy nanowires have been controllably electrodeposited on microelectrodes by applying an alternating current. The composition, morphology and alloying structures of the nanowires were characterized, revealing a single-phase alloy characteristic, highly monodispersed morphology, and controllable bimetallic compositions. The alloy nanowires were shown to exhibit electrocatalytic response characteristics for the detection of hydrogen peroxide, exhibiting a high sensitivity, low detection limit, and fast response time. The nanowire's response mechanism to hydrogen peroxide is also discussed in terms of the synergistic activity of the bimetallic binding sites, which has important implications for a better design of functional nanowires as sensing materials for a wide range of applications.

  11. Microwave-assisted oxidative digestion of lignin with hydrogen peroxide for TOC and color removal.

    PubMed

    Ouyang, Xinping; Huang, Xiangzhen; Ruan, Tao; Qiu, Xueqing

    2015-01-01

    Dilute lignin solution was successfully digested into colorless and clarified liquor under microwave-assisted oxidative digestion with hydrogen peroxide. High dosage of hydrogen peroxide is needed to effectively digest lignin, but excessive hydrogen peroxide may lead to recondensation of formed fragments in digested lignin. Microwave irradiation greatly facilitates the oxidative digestion of lignin. Compared with conventional heating technique, microwave-assisted digestion achieves the same or higher digestion rate within a shorter time and/or at lower temperature. After digestion, total organic carbon content of lignin solution decreases by 93.9%, and a small amount of aliphatic alkane, alcohol, acid and ester are formed via the cleavage of aromatic rings as well as the deprivation of side chains in original lignin. This work provides an alternative way to efficiently treat spent pulping liquor.

  12. Degradation of medical-grade polyurethane elastomers: the effect of hydrogen peroxide in vitro.

    PubMed

    Meijs, G F; McCarthy, S J; Rizzardo, E; Chen, Y C; Chatelier, R C; Brandwood, A; Schindhelm, K

    1993-03-01

    Treatment of Pellethane 2363-80A--a medical-grade poly(tetramethylene oxide)-based polyurethane elastomer--with 25% (w/w) hydrogen peroxide at 100 degrees C for times ranging from 24 h to 336 h led to significant decreases in ultimate tensile properties and decreases in molecular weight, both at the surface and in the bulk. IR spectral changes were similar to those observed after degradation in vivo. Differential scanning calorimetry showed that hydrogen-peroxide-induced degradation was associated with greater order in the hard domain and greater mobility in the soft domain. Studies conducted with low-molecular-weight model compounds for the hard and soft segments confirmed that methylene groups adjacent to oxygen were susceptible toward oxidation. The extent of degradation of a series of commercial polyurethanes on treatment with hydrogen peroxide (25%, 24 h, 100 degrees C) correlated well with their reported susceptibility to environmental stress cracking in vivo. PMID:8360204

  13. A novel aqueous dual-channel aluminum-hydrogen peroxide battery

    SciTech Connect

    Marsh, C. . Electric Propulsion); Licht, S. . Dept. of Chemistry)

    1994-06-01

    A dual-channel aluminum hydrogen peroxide battery is introduced with an open-circuit voltage of 1.9 volts, polarized losses of 0.9 mV cm[sup 2]/mA, and power densities of 1 W/cm[sup 2]. Catholyte and anolyte cell compartments are separated by an Ir/Pd modified porous nickel cathode. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode. The battery is expressed by aluminum oxidation and aqueous solution phase hydrogen peroxide reduction for an overall battery discharge consisting of 2Al + 3H[sub 2]O[sub 2] + 2 OH[sup [minus

  14. Pretreatment of cane bagasse with alkaline hydrogen peroxide for enzymatic hydrolysis of cellulose and ethanol fermentation

    SciTech Connect

    Azzam, A.M. )

    1989-01-01

    Pretreatment of the agrocellulosic waste, cane bagasse with alkaline hydrogen peroxide greatly enhances its susceptibility to enzymatic cellulolysis and thus the ethanol production from it. Various process conditions have been studied to optimize the enzymate effectiveness. These conditions include the contact time, the hydrogen peroxide concentration and the pretreatment temperature. Results obtained show, that about 50% of lignin and most of hemicellulose content of can bagasse was solubilized, by 2% alkaline hydrogen peroxide at 30{sup 0}C within 8 h. The cellulose content was consequently increased from 42% in the original cane bagasse to 75% in the oxidized pulp. Saccharification of this pulp residue with cellulase from Trichorderma viride at 45{sup 0}C for 24 h, yielded glucose with 95% efficiency. The efficiency of ethanol production from the insoluble fraction with S. cervisiae was 90% compared to about 50% for untreated cane bagasse.

  15. Photopatternable and Photoactive Hydrogel for On-demand Generation of Hydrogen Peroxide in Cell Culture

    PubMed Central

    Garland, Shaun P.; Wang, Royal Y.; Raghunathan, Vijay Krishna; Lam, Kit S.; Murphy, Christopher J.; Russell, Paul; Sun, Gang; Pan, Tingrui

    2014-01-01

    Oxidative stress, largely mediated by reactive oxygen species (ROS), is a nearly ubiquitous component in complex biological processes such as aging and disease. Optimal in vitro methods used in elucidating disease mechanisms would deliver of low levels of hydrogen peroxide, emulating the in vivo pathological state, but current methods are limited by kinetic stability or accurate measurement of the dose administered. Here we present an in vitro platform that exploits anthraquinone catalysts for the photocatalytic production of hydrogen peroxide. This system can be dynamically tuned to provide constant generation of hydrogen peroxide at a desired physiologic rate over at least 14 days and is described using a kinetic model. Material characterization and stability is discussed along with a proof-of-concept in vitro study that assessed the viability of cells as they were oxidatively challenged over 24 h at different ROS generation rates. PMID:24290809

  16. Surface Passivation of CdZnTe Detector by Hydrogen Peroxide Solution Etching

    NASA Technical Reports Server (NTRS)

    Hayes, M.; Chen, H.; Chattopadhyay, K.; Burger, A.; James, R. B.

    1998-01-01

    The spectral resolution of room temperature nuclear radiation detectors such as CdZnTe is usually limited by the presence of conducting surface species that increase the surface leakage current. Studies have shown that the leakage current can be reduced by proper surface preparation. In this study, we try to optimize the performance of CdZnTe detector by etching the detector with hydrogen peroxide solution as function of concentration and etching time. The passivation effect that hydrogen peroxide introduces have been investigated by current-voltage (I-V) measurement on both parallel strips and metal-semiconductor-metal configurations. The improvements on the spectral response of Fe-55 and 241Am due to hydrogen peroxide treatment are presented and discussed.

  17. Droplet impinging behavior on surfaces Part I - Hydrogen Peroxide on Aluminium Surface

    NASA Astrophysics Data System (ADS)

    Suwathy, R.; Manikanta Reddy, Karnati; Pramoth Kumar, M.; Venkatesan, M.

    2016-09-01

    In the present work the droplet behavior of the hydrogen peroxide (6% by weight) on a aluminum surface is reported. The behavior of hydrogen peroxide droplet is compared with water droplet for the same temperature conditions. Visualization of the droplet falling on a aluminum surface is done using a high speed camera. A data acquisition system is used for measuring the real time temperature. The characterization of droplet dynamics with variation in temperatures is detailed. The results reveal that with increase in temperature, the droplet splashes in to the ambient like a jet which is unlike water behavior, which when subjected to the same temperature conditions. The behavior of water droplet and hydrogen peroxide droplet after impinging and spreading over the surface and evaporation phenomenon is studied and observed.

  18. Assessment of redox changes to hydrogen peroxide-sensitive proteins during EGF signaling.

    PubMed

    Cuddihy, Sarah L; Winterbourn, Christine C; Hampton, Mark B

    2011-07-01

    Hydrogen peroxide acts as a second messenger in growth factor signaling where it can oxidize and modify the function of redox-sensitive proteins. While selective thiol oxidation has been measured, there has been no global assessment of protein oxidation following growth factor activation. Significant changes to the abundant and widely distributed redox sensitive thiol proteins were observed in A431 epidermoid carcinoma cells exposed to hydrogen peroxide, but no changes were observed following treatment with epidermal growth factor (EGF). This included members of the peroxiredoxin family, which were also monitored in the presence of the thioredoxin reductase inhibitor auranofin to limit their capacity to recycle to the reduced form. We conclude that widespread thiol oxidation does not occur in cells during EGF signaling, and that hydrogen peroxide must act in a highly localized or selective manner.

  19. Polarographic study of hydrogen peroxide anodic current and its application to antioxidant activity determination.

    PubMed

    Sužnjević, Desanka Ž; Pastor, Ferenc T; Gorjanović, Stanislava Ž

    2011-09-15

    Behavior of hydrogen peroxide in alkaline medium has been studied by direct current (DC) polarography with dropping mercury electrode (DME) aiming to apply it in antioxidant (AO) activity determination. Development of a peroxide anodic current having form of a peak, instead of common polarographic wave, has been investigated. As a base for this investigation the interaction of H(2)O(2) with anodically dissolved mercury was followed. Formation of mercury complex [Hg(O(2)H)(OH)] has been confirmed. The relevant experimental conditions, such as temperature, concentration and pH dependence, as well as time stability of hydrogen peroxide anodic current, have been assessed. Development of an AO assay based on decrease of anodic current of hydrogen peroxide in the presence of antioxidants (AOs) has been described. Under optimized working conditions, a series of benzoic acids along with corresponding cinnamate analogues have been tested for hydrogen peroxide scavenging activity. In addition, the assay versatility has been confirmed on various complex samples.

  20. Design of a hydrogen peroxide-activatable agent that specifically targets cancer cells.

    PubMed

    Vadukoot, Anish K; AbdulSalam, Safnas F; Wunderlich, Mark; Pullen, Eboni D; Landero-Figueroa, Julio; Mulloy, James C; Merino, Eddie J

    2014-12-15

    Some cancers, like acute myeloid leukemia (AML), use reactive oxygen species to endogenously activate cell proliferation and angiogenic signaling cascades. Thus many cancers display increases in reactive oxygen like hydrogen peroxide concentrations. To translate this finding into a therapeutic strategy we designed new hydrogen peroxide-activated agents with two key molecular pharmacophores. The first pharmacophore is a peroxide-acceptor and the second is a pendant amine. The acceptor is an N-(2,5-dihydroxyphenyl)acetamide susceptible to hydrogen peroxide oxidation. We hypothesized that selectivity between AML and normal cells could be achieved by tuning the pendant amine. Synthesis and testing of fourteen compounds that differed at the pendent amine led to the identification of an agent (14) with 2μM activity against AML cancer cells and an eleven fold-lower activity in healthy CD34+ blood stem cells. Interestingly, analysis shows that upon oxidation the pendant amine cyclizes, ejecting water, with the acceptor to give a bicyclic compound capable of reacting with nucleophiles. Preliminary mechanistic investigations show that AML cells made from addition of two oncogenes (NrasG12D and MLL-AF9) increase the ROS-status, is initially an anti-oxidant as hydrogen peroxide is consumed to activate the pro-drug, and cells respond by upregulating electrophilic defense as visualized by Western blotting of KEAP1. Thus, using this chemical approach we have obtained a simple, potent, and selective ROS-activated anti-AML agent.

  1. Manganese rescues adverse effects on lifespan and development in Podospora anserina challenged by excess hydrogen peroxide.

    PubMed

    Grimm, Carolin; Osiewacz, Heinz D

    2015-03-01

    For biological systems, balancing cellular levels of reactive oxygen species (ROS) is of great importance because ROS are both, essential for cellular signaling and dangerous in causing molecular damage. Cellular ROS abundance is controlled by a delicate network of molecular pathways. Within this network, superoxide dismutases (SODs) are active in disproportion of the superoxide anion leading to the formation of hydrogen peroxide. The fungal aging model Podospora anserina encodes at least three SODs. One of these is the mitochondrial PaSOD3 isoform containing manganese as a cofactor. Previous work resulted in the selection of strains in which PaSod3 is strongly overexpressed. These strains display impairments in growth and lifespan. A computational model suggests a series of events to occur in Sod3 overexpressing strains leading to adverse effects due to elevated hydrogen peroxide levels. In an attempt to validate this model and to obtain more detailed information about the cellular responses involved in ROS balancing, we further investigated the PaSod3 overexpressing strains. Here we show that hydrogen peroxide levels are indeed strongly increased in the mutant strain. Surprisingly, this phenotype can be rescued by the addition of manganese to the growth medium. Strikingly, while we obtained no evidence for an antioxidant effect of manganese, we found that the metal is required for induction of components of the ROS scavenging network and lowers the hydrogen peroxide level of the mutant. A similar effect of manganese on lifespan reversion was obtained in wild-type strains challenged with exogenous hydrogen peroxide. It appears that manganese is limited under high hydrogen peroxide and suggests that a manganese-dependent activity leads to the induction of ROS scavenging components.

  2. Spectrophotometric determination of hydrogen peroxide with osmium(VIII) and m-carboxyphenylfluorone.

    PubMed

    Hoshino, Mitsuru; Kamino, Shinichiro; Doi, Mitsunobu; Takada, Shingo; Mitani, Shota; Yanagihara, Rika; Asano, Mamiko; Yamaguchi, Takako; Fujita, Yoshikazu

    2014-01-01

    Spectrophotometric determination of hydrogen peroxide was accomplished with osmium(VIII) and m-carboxyphenylfluorone (MCPF) in the presence of cetyltrimethylammonium chloride (CTAC). In the determination of hydrogen peroxide based on the fading of the color of osmium(VIII)-MCPF complex, Beer's law was obeyed in the range 20-406 ng mL(-1), with an effective molar absorption coefficient (at 580 nm) of 5.21×10(4) L mol(-1) cm(-1) and a relative standard deviation of 0.33% (n=6). Further, we performed the characterization of MCPF and obtained the crystal structure.

  3. Power generation in fuel cells using liquid methanol and hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor); Chun, William (Inventor)

    2002-01-01

    The invention is directed to an encapsulated fuel cell including a methanol source that feeds liquid methanol (CH.sub.3 OH) to an anode. The anode is electrical communication with a load that provides electrical power. The fuel cell also includes a hydrogen peroxide source that feeds liquid hydrogen peroxide (H.sub.2 O.sub.2) to the cathode. The cathode is also in communication with the electrical load. The anode and cathode are in contact with and separated by a proton-conducting polymer electrolyte membrane.

  4. Hydrogen Peroxide Promoted Mizoroki-Heck Reactions of Phenyldiazenes with Acrylates, Acrylamides, and Styrenes.

    PubMed

    Lasch, Roman; Fehler, Stefanie K; Heinrich, Markus R

    2016-04-01

    Mizoroki-Heck reactions, which are well-known for aryldiazonium salts and which have recently been described for arylhydrazines, have now been extended to phenyldiazenes. In situ generation of phenyldiazenes from azocarboxylates allowed clean and selective reactions with styrenes, acrylates, and acrylamides using palladium(II) acetate in the presence of silver(I) acetate or hydrogen peroxide as oxidant. Hydrogen peroxide was thereby shown to be a cheap and broadly applicable alternative for the established palladium-silver(I) system. PMID:26974469

  5. Nerve growth factor promotes killing of Leishmania donovani by macrophages through the induction of hydrogen peroxide.

    PubMed

    Chiba, Rieko; Amagai, Yosuke; Tanaka, Akane; Katakura, Ken; Matsuda, Hiroshi

    2014-08-01

    Visceral leishmaniasis is protozoonosis that occurs worldwide and still requires effective therapies with less toxicity. In this study, we examined the antileishmanial effect of nerve growth factor (NGF) using a murine infection model. NGF blocked the infection of macrophages by Leishmania donovani, which was completely cancelled by a hydrogen peroxide inhibitor. In vivo, not only did NGF show antileishmanial effects, but combination therapy of NGF and sodium stibogluconate synergistically exhibited the activity more potently than each monotherapy. These results indicate that NGF exerts antileishmanial effect by stimulating hydrogen peroxide production in macrophages and can be a novel therapy for leishmaniasis.

  6. Carbon Sources for Yeast Growth as a Precondition of Hydrogen Peroxide Induced Hormetic Phenotype.

    PubMed

    Vasylkovska, Ruslana; Petriv, Natalia; Semchyshyn, Halyna

    2015-01-01

    Hormesis is a phenomenon of particular interest in biology, medicine, pharmacology, and toxicology. In this study, we investigated the relationship between H2O2-induced hormetic response in S. cerevisiae and carbon sources in yeast growth medium. In general, our data indicate that (i) hydrogen peroxide induces hormesis in a concentration-dependent manner; (ii) the effect of hydrogen peroxide on yeast reproductive ability depends on the type of carbon substrate in growth medium; and (iii) metabolic and growth rates as well as catalase activity play an important role in H2O2-induced hormetic response in yeast. PMID:26843865

  7. Transformation of wood during ozonization in the presence of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Mamleeva, N. A.; Abrosimova, G. E.; Kharlanov, A. N.; Lunin, V. V.

    2013-07-01

    Samples of ozonized aspen wood pretreated with hydrogen peroxide solutions of various concentrations are investigated by UV diffuse reflectance spectroscopy, IR spectroscopy, and X-ray structural analysis. The general course of wood transformation under the action of the O3/H2O2 system is associated with the destruction of lignin and oxidation of carbohydrates, raising the fraction of the crystalline phase in a lignocarbohydrate material. The possibility of varying the depth of the chemical and structural transformation of the substrate upon changing the hydrogen peroxide concentration in the O3/H2O2 system is demonstrated.

  8. Role of endogenous hydrogen peroxide in the development of nitrate tolerance.

    PubMed

    Ghatta, Srinivas; Hemmer, Ross B; Uppala, Saritha; O'Rourke, Stephen T

    2007-04-01

    The present study was designed to test the hypothesis that hydrogen peroxide plays a role in the development of nitrate tolerance. Isolated rat aortic rings were suspended in organ chambers for isometric tension recording. The rings were incubated with (tolerant) and without (control) nitroglycerin (10(-4) M) for 90 min, followed by repeated rinsing for 1 h. Hydrogen peroxide release in control and tolerant tissues was measured fluorimetrically using amplex red. Nitroglycerin (10(-9)-10(-4) M) caused concentration-dependent relaxations in control (-logEC50=7.15+/-0.1) and tolerant rings (-logEC50=5.83+/-0.1) contracted with norepinephrine. Nitrate tolerance was evident by a >20-fold rightward shift in the nitroglycerin concentration-response curve in tissues exposed previously to nitroglycerin for 90 min. Incubation of the rings with the superoxide dismutase (SOD)-mimetic, tempol (10(-4) M), during the 90-min exposure period to nitroglycerin caused a leftward shift in the nitroglycerin concentration-response curve in tolerant rings (-logEC50=6.84+/-0.2), but had no effect on the response to nitroglycerin in control rings. Treatment of the rings with catalase (1200 U/ml) or ebselen (1.5x10(-5) M), a glutathione peroxidase-mimetic, during the 90-min exposure period to nitroglycerin resulted in a further rightward shift in the nitroglycerin concentration-response curve in tolerant rings (-logEC50=5.41+/-0.1 and 4.98+/-0.1; catalase and ebselen respectively), without altering the response to nitroglycerin in control rings. In the presence of catalase, the effect of tempol on nitrate tolerance was abolished (-logEC50=5.46+/-0.1). Hydrogen peroxide release was reduced by approximately 64% in nitrate tolerant tissues when compared to control. The decrease in hydrogen peroxide release was completely reversed by treatment with tempol, whereas treatment with ebselen caused a further decrease in hydrogen peroxide release in nitrate tolerant tissues. Addition of hydrogen

  9. Artificial photosynthesis for production of hydrogen peroxide and its fuel cells.

    PubMed

    Fukuzumi, Shunichi

    2016-05-01

    The reducing power released from photosystem I (PSI) via ferredoxin enables the reduction of NADP(+) to NADPH, which is essential in the Calvin-Benson cycle to make sugars in photosynthesis. Alternatively, PSI can reduce O2 to produce hydrogen peroxide as a fuel. This article describes the artificial version of the photocatalytic production of hydrogen peroxide from water and O2 using solar energy. Hydrogen peroxide is used as a fuel in hydrogen peroxide fuel cells to make electricity. The combination of the photocatalytic H2O2 production from water and O2 using solar energy with one-compartment H2O2 fuel cells provides on-site production and usage of H2O2 as a more useful and promising solar fuel than hydrogen. This article is part of a Special Issue entitled Biodesign for Bioenergetics--The design and engineering of electronc transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.

  10. Hydrogen Peroxide Induced Changes in Energy Status and Respiration Metabolism of Harvested Longan Fruit in Relation to Pericarp Browning.

    PubMed

    Lin, Yi-Xiong; Lin, Yi-Fen; Chen, Yi-Hui; Wang, Hui; Shi, John; Lin, He-Tong

    2016-06-01

    Energy status and respiration metabolism of "Fuyan" longan fruit treated by hydrogen peroxide (H2O2) and their relationship to pericarp browning were studied. The results displayed that H2O2 significantly increased the respiration rate, increased activities of respiratory terminal oxidases like cytochrome C oxidase (CCO) and ascorbic acid oxidase (AAO), decreased NAD kinase activity, maintained lower contents of NADP and NADPH as well as higher amounts of NAD and NADH, and accelerated the decrease of energy charge. These results gave convincing evidence that the treatment of H2O2 for accelerating longan pericarp browning was due to an increase of energy deficiency, an increase of respiratory metabolic pathways of Embden-Meyerhof pathway (EMP) and tricarboxylic acid (TCA) cycle, a decrease of pentose phosphate pathway (PPP) of respiratory pathway, and an increase of activities of respiratory terminal oxidases like CCO and AAO. PMID:27213701

  11. Hydrogen Peroxide Induced Changes in Energy Status and Respiration Metabolism of Harvested Longan Fruit in Relation to Pericarp Browning.

    PubMed

    Lin, Yi-Xiong; Lin, Yi-Fen; Chen, Yi-Hui; Wang, Hui; Shi, John; Lin, He-Tong

    2016-06-01

    Energy status and respiration metabolism of "Fuyan" longan fruit treated by hydrogen peroxide (H2O2) and their relationship to pericarp browning were studied. The results displayed that H2O2 significantly increased the respiration rate, increased activities of respiratory terminal oxidases like cytochrome C oxidase (CCO) and ascorbic acid oxidase (AAO), decreased NAD kinase activity, maintained lower contents of NADP and NADPH as well as higher amounts of NAD and NADH, and accelerated the decrease of energy charge. These results gave convincing evidence that the treatment of H2O2 for accelerating longan pericarp browning was due to an increase of energy deficiency, an increase of respiratory metabolic pathways of Embden-Meyerhof pathway (EMP) and tricarboxylic acid (TCA) cycle, a decrease of pentose phosphate pathway (PPP) of respiratory pathway, and an increase of activities of respiratory terminal oxidases like CCO and AAO.

  12. Flow injection analysis of organic peroxide explosives using acid degradation and chemiluminescent detection of released hydrogen peroxide.

    PubMed

    Mahbub, Parvez; Zakaria, Philip; Guijt, Rosanne; Macka, Mirek; Dicinoski, Greg; Breadmore, Michael; Nesterenko, Pavel N

    2015-10-01

    The applicability of acid degradation of organic peroxides into hydrogen peroxide in a pneumatically driven flow injection system with chemiluminescence reaction with luminol and Cu(2+) as a catalyst (FIA-CL) was investigated for the fast and sensitive detection of organic peroxide explosives (OPEs). The target OPEs included hexamethylene triperoxide diamine (HMTD), triacetone triperoxide (TATP) and methylethyl ketone peroxide (MEKP). Under optimised conditions maximum degradations of 70% and 54% for TATP and HMTD, respectively were achieved at 162 µL min(-1), and 9% degradation for MEKP at 180 µL min(-1). Flow rates were precisely controlled in this single source pneumatic pressure driven multi-channel FIA system by model experiments on mixing of easily detectable component solutions. The linear range for detection of TATP, HMTD and H2O2 was 1-200 µM (r(2)=0.98-0.99) at both flow rates, while that for MEKP was 20-200 µM (r(2)=0.97) at 180 µL min(-1). The detection limits (LODs) obtained were 0.5 µM for TATP, HMTD and H2O2 and 10 µM for MEKP. The detection times varied from 1.5 to 3 min in this FIA-CL system. Whilst the LOD for H2O2 was comparable with those reported by other investigators, the LODs and analysis times for TATP and HMTD were superior, and significantly, this is the first time the detection of MEKP has been reported by FIA-CL. PMID:26078148

  13. Flow injection analysis of organic peroxide explosives using acid degradation and chemiluminescent detection of released hydrogen peroxide.

    PubMed

    Mahbub, Parvez; Zakaria, Philip; Guijt, Rosanne; Macka, Mirek; Dicinoski, Greg; Breadmore, Michael; Nesterenko, Pavel N

    2015-10-01

    The applicability of acid degradation of organic peroxides into hydrogen peroxide in a pneumatically driven flow injection system with chemiluminescence reaction with luminol and Cu(2+) as a catalyst (FIA-CL) was investigated for the fast and sensitive detection of organic peroxide explosives (OPEs). The target OPEs included hexamethylene triperoxide diamine (HMTD), triacetone triperoxide (TATP) and methylethyl ketone peroxide (MEKP). Under optimised conditions maximum degradations of 70% and 54% for TATP and HMTD, respectively were achieved at 162 µL min(-1), and 9% degradation for MEKP at 180 µL min(-1). Flow rates were precisely controlled in this single source pneumatic pressure driven multi-channel FIA system by model experiments on mixing of easily detectable component solutions. The linear range for detection of TATP, HMTD and H2O2 was 1-200 µM (r(2)=0.98-0.99) at both flow rates, while that for MEKP was 20-200 µM (r(2)=0.97) at 180 µL min(-1). The detection limits (LODs) obtained were 0.5 µM for TATP, HMTD and H2O2 and 10 µM for MEKP. The detection times varied from 1.5 to 3 min in this FIA-CL system. Whilst the LOD for H2O2 was comparable with those reported by other investigators, the LODs and analysis times for TATP and HMTD were superior, and significantly, this is the first time the detection of MEKP has been reported by FIA-CL.

  14. Where have all the bubbles gone? An ode to Hydrogen peroxide, the champagne of all wound cleaners.

    PubMed

    Rees, Jacqueline E

    2003-04-01

    Hydrogen peroxide solution can be very effective for cleaning grit filled wounds and grazes. Its use in Accident and Emergency (A&E) departments has gone out of vogue due to concerns about air emboli formation. This article discusses the truth behind these concerns and whether it is in fact safe to use hydrogen peroxide solution for wound cleaning in specific situations.

  15. Efficient Method for the Determination of the Activation Energy of the Iodide-Catalyzed Decomposition of Hydrogen Peroxide

    ERIC Educational Resources Information Center

    Sweeney, William; Lee, James; Abid, Nauman; DeMeo, Stephen

    2014-01-01

    An experiment is described that determines the activation energy (E[subscript a]) of the iodide-catalyzed decomposition reaction of hydrogen peroxide in a much more efficient manner than previously reported in the literature. Hydrogen peroxide, spontaneously or with a catalyst, decomposes to oxygen and water. Because the decomposition reaction is…

  16. Paper-based vapor detection of hydrogen peroxide: colorimetric sensing with tunable interface.

    PubMed

    Xu, Miao; Bunes, Benjamin R; Zang, Ling

    2011-03-01

    Vapor detection of hydrogen peroxide still remains challenging for conventional sensing techniques, though such vapor detection implies important applications in various practical areas, including locating IEDs. We report herein a new colorimetric sensor system that can detect hydrogen peroxide vapor down to parts per billion level. The sensory materials are based on the cellulose microfibril network of paper towels, which provide a tunable interface for modification with Ti(IV) oxo complexes for binding and reacting with H(2)O(2). The Ti(IV)-peroxide bond thus formed turns the complex from colorless to bright yellow with an absorption maximum around 400 nm. Such complexation-induced color change is exclusively selective for hydrogen peroxide, with no color change observed in the presence of water, oxygen, common organic reagents or other chelating reagents. This paper-based sensor material is disposable and one-time use, representing a cheap, simple approach to detect peroxide vapors. The reported sensor system also proves the technical feasibility of developing enhanced colorimetric sensing using nanofibril materials that will provide plenty of room to enlarge the surface area (by shrinking the fiber size), so as to enhance the surface interaction with gas phase. PMID:21355618

  17. On the transferability of atomic contributions to the optical rotatory power of hydrogen peroxide, methyl hydroperoxide and dimethyl peroxide

    NASA Astrophysics Data System (ADS)

    Sánchez, Marina; Alkorta, Ibon; Elguero, José; Ferraro, Marta B.; Sauer, Stephan P. A.

    2014-06-01

    The chirality of molecules expresses itself, for example, in the fact that a solution of a chiral molecule rotates the plane of linear polarised light. The underlying molecular property is the optical rotatory power (ORP) tensor, which according to time-dependent perturbation theory can be calculated as mixed linear response functions of the electric and magnetic dipole moment operators. Applying a canonical transformation of the Hamiltonian, which reformulates the magnetic dipole moment operator in terms of the operator for the torque acting on the electrons, the ORP of a molecule can be partitioned into atomic and group contributions. In the present work, we investigate the transferability of such individual contributions in a series of small, chiral molecules: hydrogen peroxide, methyl hydroperoxide and dimethyl peroxide. The isotropic atomic or group contributions have been evaluated for the hydrogen, oxygen and carbon atoms as well as for the methyl group at the level of time-dependent density functional theory with the B3LYP exchange-correlation functional employing a large Gaussian basis set. We find that the atomic or group contributions are not transferable among these three molecules.

  18. Study of use of different types of hydrogen peroxides (2006-2008).

    PubMed

    Vissers, Marc; Van Parys, Pieter; Audenaert, Joachim; Kerger, Pierrot; De Windt, Wim; Dick, Jan; Gobin, Bruno

    2009-01-01

    Hydrogen peroxides are commonly used in greenhouses for cleaning purposes and disinfection of irrigation water systems, i.e., to prevent clogging by duckweed (Lemna minor), algae and other (micro)organisms. This use contains a potential risk of involuntary contact to the plants, e.g., to roots through irrigation or to the plant leaves through accidental droplets (spraying mist). To help growers to maximize disinfection with minimal risks, the efficacy and plant safety of a variety of commercial available peroxide formulations were compared, i.e., pure peroxide products, peroxide products with additives: Ag, performic acid, peracetic acid and sorbitol. Starting from pure (clean and without fertilizers) irrigation water the peroxides with Ag-stabilisers were most stable and most effective for algae prevention. In screenings for the curative effect on algae, duckweed and bacteria the best results were obtained with peroxide formulations with performic acid. In plant safety tests on potted Ficus benjamina, sprays and irrigations above the plants gave no toxicity till 500 ppm a.i.; irrigations below the plants didn't show toxicity but the plant growth was reduced with weekly applications of 2000 ppm a.i. On the contrary several applications were risky on herbaceous plants, sometimes even with very low dosages (12.5 ppm peroxide).

  19. Hydrogen peroxide activates focal adhesion kinase and c-Src by a phosphatidylinositol 3 kinase-dependent mechanism and promotes cell migration in Caco-2 cell monolayers.

    PubMed

    Basuroy, Shyamali; Dunagan, Mitzi; Sheth, Parimal; Seth, Ankur; Rao, R K

    2010-07-01

    Recent studies showed that c-Src and phosphatidylinositol 3 (PI3) kinase mediate the oxidative stress-induced disruption of tight junctions in Caco-2 cell monolayers. The present study evaluated the roles of PI3 kinase and Src kinase in the oxidative stress-induced activation of focal adhesion kinase (FAK) and acceleration of cell migration. Oxidative stress, induced by xanthine and xanthine oxidase system, rapidly increased phosphorylation of FAK on Y397, Y925, and Y577 in the detergent-insoluble and soluble fractions and increased its tyrosine kinase activity. The PI3 kinase inhibitors, wortmannin and LY294002, and the Src kinase inhibitor, 4-amino-5[chlorophyll]-7-[t-butyl]pyrazolo[3-4-d]pyrimidine, attenuated tyrosine phosphorylation of FAK. Oxidative stress induced phosphorylation of c-Src on Y418 by a PI3 kinase-dependent mechanism, whereas oxidative stress-induced activation of PI3 kinase was independent of Src kinase activity. Hydrogen peroxide accelerated Caco-2 cell migration in a concentration-dependent manner. Promotion of cell migration by hydrogen peroxide was attenuated by LY294002 and PP2. Reduced expression of FAK by siRNA attenuated hydrogen peroxide-induced acceleration of cell migration. The expression of constitutively active c-Src(Y527F) enhanced cell migration, whereas the expression of dominant negative c-Src(K296R/Y528F) attenuated hydrogen peroxide-induced stimulation of cell migration. Oxidative stress-induced activation of c-Src and FAK was associated with a rapid increase in the tyrosine phosphorylation and the levels of paxillin and p130(CAS) in actin-rich, detergent-insoluble fractions. This study shows that oxidative stress activates FAK and accelerates cell migration in an intestinal epithelium by a PI3 kinase- and Src kinase-dependent mechanism. PMID:20378826

  20. Use of hydrogen peroxide treatment and crystal violet agar plates for selective recovery of bacteriophages from natural environments

    SciTech Connect

    Asghari, A.; Farrah, S.R.; Bitton, G. )

    1992-04-01

    Hydrogen peroxide inactivated bacteriophages and bacteria at different rates. A concentration of 0.1% hydrogen peroxide reduced the numbers of several bacteria by an average of 94% but caused an average of 25% inactivation in the numbers of bacteriophages tested. Treating natural samples with hydrogen peroxide selectively reduced the indigenous bacterial flora and permitted better visualization of plaques of lawns of Escherichia coli C-3000. In some cases indigenous gram-positive bacteria were relatively resistant to hydrogen peroxide, but their growth could be limited by incorporation of crystal violet into the bottom agar used for plaque assays. The use of hydrogen peroxide treatment and crystal violet-containing plates permitted recovery of more phages from natural samples than did other procedures, such as chloroform pretreatment or the use of selective plating agar such as EC medium.

  1. Rational Design of an α-Ketoamide-Based Near-Infrared Fluorescent Probe Specific for Hydrogen Peroxide in Living Systems.

    PubMed

    Xie, Xilei; Yang, Xiu'e; Wu, Tianhong; Li, Yong; Li, Mengmeng; Tan, Qi; Wang, Xu; Tang, Bo

    2016-08-16

    Hydrogen peroxide, an important biomolecule, receives earnest attention because of its physiological and pathological functions. In this Article, we present the rational design, characterization, and biological application of a mitochondria-targetable NIR fluorescent sensor, Mito-NIRHP, for hydrogen peroxide visualization. Mito-NIRHP utilizes a unique reaction switch, α-ketoamide moiety, to turn on a highly specific, sensitive, and rapid fluorescence response toward hydrogen peroxide coupled with the intramolecular charge transfer strategy. Mito-NIRHP is competent to track endogenously produced hydrogen peroxide in both living cells and living animals. In addition, utilizing Mito-NIRHP, overgeneration of hydrogen peroxide during ischemia-reperfusion injury was directly visualized at both cell and organ levels.

  2. Antitumor effect of synergistic contribution of nitrite and hydrogen peroxide in the plasma activated medium

    NASA Astrophysics Data System (ADS)

    Kurake, Naoyuki; Tanaka, Hiromasa; Ishikawa, Kenji; Nakamura, Kae; Kajiyama, Hiroaki; Kikkawa, Fumiaki; Kondo, Takashi; Mizuno, Masaaki; Takeda, Keigo; Kondo, Hiroki; Sekine, Makoto; Hori, Masaru

    2015-09-01

    Non-equilibrium atmospheric pressure plasmas (NEAPP) have been attracted attention in the noble application of cancer therapy. Although good effects of the Plasma-Activated-Medium (PAM) such as the selective antitumor effect and killing effect for the anticancer agent resistant cells were reported, a mechanism of this effect has not been still clarified yet. In this study, we have investigated a contribution of the reactive nitrogen and oxygen species (RNOS) generated in PAM such as hydrogen peroxide and nitrite. Those species generated in the PAM quantitatively measured by light absorbance of commercial regent. Moreover, viable cell count after cell culture with those RNOS intentionally added medium or PAM were also measured by MTS assay. Our NEAPP source generated hydrogen peroxide and nitrite with the generation ratio of 0.35 μM/s and 9.8 μM/s. In those RNOS, hydrogen peroxide has respective antitumor effect. On the other hands, nitrite has no antitumor effect singly. But, synergistically enhance the antitumor effect of hydrogen peroxide. Moreover, this effect of those RNOS also contribute for the selectively cancer killing effect of PAM.

  3. EXPOXIDATION OF OLEFINS AND α,β-UNSATURATED KEYTONES OVER SONOCHEMICALLY PREPARED HYDROXYAPATITES USING HYDROGEN PEROXIDE

    EPA Science Inventory

    An effective and environmentally friendly protocol for the epoxidation of olefins and α,β-unsaturated ketones in the presence of hydroxyapatite as catalyst using hydrogen peroxide is described. The catalyst is active and reusable for the selective epoxidation of a variety...

  4. Clinical use of hydrogen peroxide in surgery and dentistry--why is there a safety issue?

    PubMed

    Patel, V; Kelleher, M; McGurk, M

    2010-01-23

    The use of hydrogen peroxide (HP) is limited in dental surgery by UK interpretation of EC legislation. The product, however, has wide application in surgery, particularly in the debridement of wounds. Its use in sensitive areas such as the carotid artery and vein illustrate its value in safely cleaning wounds.

  5. Evaluation of a sporicidal peracetic acid/hydrogen peroxide-based daily disinfectant cleaner.

    PubMed

    Deshpande, Abhishek; Mana, Thriveen S C; Cadnum, Jennifer L; Jencson, Annette C; Sitzlar, Brett; Fertelli, Dennis; Hurless, Kelly; Kundrapu, Sirisha; Sunkesula, Venkata C K; Donskey, Curtis J

    2014-11-01

    OxyCide Daily Disinfectant Cleaner, a novel peracetic acid/hydrogen peroxide-based sporicidal disinfectant, was as effective as sodium hypochlorite for in vitro killing of Clostridium difficile spores, methicillin-resistant Staphylococcus aureus, and vancomcyin-resistant enterococci. OxyCide was minimally affected by organic load and was effective in reducing pathogen contamination in isolation rooms.

  6. Oxidation of benzene with hydrogen peroxide catalyzed with ferrocene in the presence of pyrazine carboxylic acid

    NASA Astrophysics Data System (ADS)

    Shul'pina, L. S.; Durova, E. L.; Kozlov, Yu. N.; Kudinov, A. R.; Strelkova, T. V.; Shul'pin, G. B.

    2013-12-01

    It is found that ferrocene in the presence of small amounts of pyrazine carboxylic acid (PCA) effectively catalyzes the oxidation of benzene to phenol with hydrogen peroxide. Two main differences upon the oxidation of two different substrates, i.e., cyclohexane and benzene, with the same H2O2-ferrocene-PCA catalytic system are revealed: the rates of benzene oxidation and hydrogen peroxide decomposition are several times lower than the rate of cyclohexane oxidation at close concentrations of both substrates, and the rate constant ratios for the reactions of oxidizing particles with benzene and acetonitrile are significantly lower than would be expected for reactions involving free hydroxyl radicals. The overall rate of hydrogen peroxide decomposition, including both the catalase and oxidase routes, is lower in the presence of benzene than in the presence of cyclohexane. It is suggested on the grounds of these data that a catalytically active particle different from the one generated in the absence of benzene is formed in the presence of benzene. This particle catalyzes hydrogen peroxide decomposition less efficiently than the initial complex and generates a dissimilar oxidizing particle that exhibits higher selectivity. It is shown that reactivity of the system at higher concentrations of benzene differs from that of an initial system not containing an aromatic component with the capability of π-coordination with metal ions.

  7. Lung edema due to hydrogen peroxide is independent of cyclooxygenase products

    SciTech Connect

    Burghuber, O.; Mathias, M.M.; McMurtry, I.F.; Reeves, J.T.; Voelkel, N.F.

    1984-01-01

    Active oxygen species can cause lung injury. Although a direct action on endothelial cells is proposed, the possibility exists that they might cause injury via mediators. We considered that active oxygen species would stimulate the generation of cyclooxygenase metabolites, which then alter pulmonary vasoreactivity and cause edema. We chemically produced hydrogen peroxide by adding glucose oxidase to a plasma- and cell-free, but ..beta..-D-glucose-containing, solution, which perfused isolated rat lungs. Addition of glucose oxidase to the perfusate caused a marked decrease in pulmonary vasoreactivity, accompanied by an increase in the concentrations of prostacyclin, thromboxane A/sub 2/, and prostaglandin F/sub 2..cap alpha../. Pretreatment with catalase, a specific scavenger of hydrogen peroxide, preserved pulomonary vasoreactivity, inhibited the increase of the concentration of the measured prostaglandins, and prevented edema formation. Indomethacin effectively blocked lung prostaglandin production but neither prevented the decrease in vasoreactivity nor inhibited edema formation. From these data we conclude the hydrogen peroxide impaired pulmonary vasoreactivity and subsequently caused edema. Depsite the fact that hydrogen peroxide stimulated lung prostaglandin production, cyclooxygenase-derived products neither caused the decrease in vasoreactivity nor the development of edema.

  8. Effect of ultrasonic pre-treatment of thermomechanical pulp on hydrogen peroxide bleaching

    NASA Astrophysics Data System (ADS)

    Loranger, E.; Charles, A.; Daneault, C.

    2012-12-01

    Ultrasound pre-treatments of softwood TMP had been carried to evaluate its impact on the efficiency of hydrogen peroxide bleaching. The trials were performed after a factorial design of experiment using frequency, power and time as variables. The experiments were conducted in an ultrasonic bath and then bleached with hydrogen peroxide. Measurements such as brightness, L*A*B* color system coordinate, residual hydrogen peroxide and metal content were evaluated on bleached pulp. The results indicate that the effect of ultrasonic treatment on brightness was dependent on the ultrasound frequency used; the brightness increased slightly at 68 kHz and decreased at 40 and 170 kHz. These results were correlated to the ultrasound effect on the generation of transition metals (copper, iron and manganese) which are responsible for catalytic decomposition of hydrogen peroxide. The influence of metal interference was minimized by using a chelating agent such as diethylene triamine pentaacetic acid (DTPA). With the results obtained in this study we have identified a set of option conditions, e.g. 1000 W, 40 kHz, 1.5 % consistency and 0.2% addition of DTPA prior to the bleaching stage (after ultrasonic pre-treatment) who improve brightness by 2.5 %ISO.

  9. Mouthwashes with hydrogen peroxide are carcinogenic, but are freely indicated on the Internet: warn your patients!

    PubMed

    Consolaro, Alberto

    2013-01-01

    It all began in Ancient Egypt where people used to bleach their teeth with antiseptic mouthwashes made of urea from human urine. Teeth harmony is promoted by expression of feelings, communication, a real window of the brain and its content! Tooth bleaching products are medicines, not cosmetics! Mouth washing with hydrogen peroxide is an illogical and dangerous procedure! Hydrogen peroxide must be used in one's mouth only when employed by a dentist who has been properly instructed to protect the mucosa, preventing it from receiving these products. How and for how long these products are going to be used require caution in order to avoid or decrease any adverse effects on the tissues. Many websites instruct people on how to purchase and prepare hydrogen peroxide so that it is used as an antiseptic mouthwash and tooth bleaching agent. Some websites even refer to dentists as "exploiters", accusing them of not instructing patients properly. In this article, we aim at providing evidence and information upon which dentists and assistants may base their thinking as well as their opinion and procedures regarding "the indiscriminate and free use of hydrogen peroxide in the mouth, on teeth and oral mucosa". Those websites, blogs and social network profiles trespass the limits of public trust and should be immediately sued by the government for committing a crime against public health.

  10. Optimization study on the hydrogen peroxide pretreatment and production of bioethanol from seaweed Ulva prolifera biomass.

    PubMed

    Li, Yinping; Cui, Jiefen; Zhang, Gaoli; Liu, Zhengkun; Guan, Huashi; Hwang, Hueymin; Aker, Winfred G; Wang, Peng

    2016-08-01

    The seaweed Ulva prolifera, distributed in inter-tidal zones worldwide, contains a large percentage of cellulosic materials. The technical feasibility of using U. prolifera residue (UPR) obtained after extraction of polysaccharides as a renewable energy resource was investigated. An environment-friendly and economical pretreatment process was conducted using hydrogen peroxide. The hydrogen peroxide pretreatment improved the efficiency of enzymatic hydrolysis. The resulting yield of reducing sugar reached a maximum of 0.42g/g UPR under the optimal pretreatment condition (hydrogen peroxide 0.2%, 50°C, pH 4.0, 12h). The rate of conversion of reducing sugar in the concentrated hydrolysates to bioethanol reached 31.4% by Saccharomyces cerevisiae fermentation, which corresponds to 61.7% of the theoretical maximum yield. Compared with other reported traditional processes on Ulva biomass, the reducing sugar and bioethanol yield are substantially higher. Thus, hydrogen peroxide pretreatment is an effective enhancement of the process of bioethanol production from the seaweed U. prolifera.

  11. Optimization study on the hydrogen peroxide pretreatment and production of bioethanol from seaweed Ulva prolifera biomass.

    PubMed

    Li, Yinping; Cui, Jiefen; Zhang, Gaoli; Liu, Zhengkun; Guan, Huashi; Hwang, Hueymin; Aker, Winfred G; Wang, Peng

    2016-08-01

    The seaweed Ulva prolifera, distributed in inter-tidal zones worldwide, contains a large percentage of cellulosic materials. The technical feasibility of using U. prolifera residue (UPR) obtained after extraction of polysaccharides as a renewable energy resource was investigated. An environment-friendly and economical pretreatment process was conducted using hydrogen peroxide. The hydrogen peroxide pretreatment improved the efficiency of enzymatic hydrolysis. The resulting yield of reducing sugar reached a maximum of 0.42g/g UPR under the optimal pretreatment condition (hydrogen peroxide 0.2%, 50°C, pH 4.0, 12h). The rate of conversion of reducing sugar in the concentrated hydrolysates to bioethanol reached 31.4% by Saccharomyces cerevisiae fermentation, which corresponds to 61.7% of the theoretical maximum yield. Compared with other reported traditional processes on Ulva biomass, the reducing sugar and bioethanol yield are substantially higher. Thus, hydrogen peroxide pretreatment is an effective enhancement of the process of bioethanol production from the seaweed U. prolifera. PMID:27132221

  12. Electrodeposited nanostructured MnO{sub 2} for non-enzymatic hydrogen peroxide sensing

    SciTech Connect

    Saha, B. Jana, S. K.; Banerjee, S.

    2015-06-24

    Electrodeposited MnO{sub 2} nanostructure was synthesized on indium tin oxide coated glass electrode by cyclic voltammetry. The as obtained samples were subsequently characterized by atomic force microscopy and their electro-catalytic response towards hydrogen peroxide in alkaline medium of 0.1M NaOH was studied using cyclic voltammetry and amperometry.

  13. The Feasibility of Using Hydrogen Peroxide Decomposition Studies for High School Chemistry.

    ERIC Educational Resources Information Center

    Carter, Gillian E.

    1986-01-01

    Highlights difficulties that occur when teachers attempt to devise new experiments (use of hydrogen peroxide decomposition) and how seemingly useless results can be turned into productive student projects. Considers effects of ions present in tap water, pH, dust, and nature of vessel's surface. Reaction order and safety precautions are noted. (JN)

  14. First Principles Modeling of the Performance of a Hydrogen-Peroxide-Driven Chem-E-Car

    ERIC Educational Resources Information Center

    Farhadi, Maryam; Azadi, Pooya; Zarinpanjeh, Nima

    2009-01-01

    In this study, performance of a hydrogen-peroxide-driven car has been simulated using basic conservation laws and a few numbers of auxiliary equations. A numerical method was implemented to solve sets of highly non-linear ordinary differential equations. Transient pressure and the corresponding traveled distance for three different car weights are…

  15. Electrodeposited nanostructured MnO2 for non-enzymatic hydrogen peroxide sensing

    NASA Astrophysics Data System (ADS)

    Saha, B.; Jana, S. K.; Banerjee, S.

    2015-06-01

    Electrodeposited MnO2 nanostructure was synthesized on indium tin oxide coated glass electrode by cyclic voltammetry. The as obtained samples were subsequently characterized by atomic force microscopy and their electro-catalytic response towards hydrogen peroxide in alkaline medium of 0.1M NaOH was studied using cyclic voltammetry and amperometry.

  16. CATALYTIC OXIDATION OF ALCOHOLS AND EPOXIDATION OF OLEFINS WITH HYDROGEN PEROXIDE AS OXIDANT

    EPA Science Inventory

    Hydrogen peroxide (H2O2) is an ideal oxidant of choice for these oxidations due to economic and environmental reasons by giving water as a by-product. Two catalysts used are vanadium phosphorus oxide (VPO) and Fe3+/montmorillonite-K10 catalyst prepared by ion-exchange method at a...

  17. SELECTIVE OXIDATION OF ALCOHOLS OVER VANADIUM PHOSPHORUS OXIDE CATALYST USING HYDROGEN PEROXIDE

    EPA Science Inventory

    Oxidation of various alcohols is studied in liquid phase under nitrogen atmosphere over vanadium phosphorus oxide catalyst in an environmentally friendly protocol using hydrogen peroxide. The catalyst and the method are found to be suitable for the selective oxidation of a variet...

  18. OXIDATION OF ALCOHOLS OVER FE3+/MONTMORILLONITE-K10 USING HYDROGEN PEROXIDE

    EPA Science Inventory

    Oxidation of various primary and secondary alcohols is studied in liquid phase at atmospheric pressure over Fe3+/montmorillonite-K10 catalyst prepared by ion-exchange method at a pH of 4 in an environmentally friendly protocol using hydrogen peroxide. The catalyst and the method ...

  19. Development of a sterilizing in-place application for a production machine using Vaporized Hydrogen Peroxide.

    PubMed

    Mau, T; Hartmann, V; Burmeister, J; Langguth, P; Häusler, H

    2004-01-01

    The use of steam in sterilization processes is limited by the implementation of heat-sensitive components inside the machines to be sterilized. Alternative low-temperature sterilization methods need to be found and their suitability evaluated. Vaporized Hydrogen Peroxide (VHP) technology was adapted for a production machine consisting of highly sensitive pressure sensors and thermo-labile air tube systems. This new kind of "cold" surface sterilization, known from the Barrier Isolator Technology, is based on the controlled release of hydrogen peroxide vapour into sealed enclosures. A mobile VHP generator was used to generate the hydrogen peroxide vapour. The unit was combined with the air conduction system of the production machine. Terminal vacuum pumps were installed to distribute the gas within the production machine and for its elimination. In order to control the sterilization process, different physical process monitors were incorporated. The validation of the process was based on biological indicators (Geobacillus stearothermophilus). The Limited Spearman Karber Method (LSKM) was used to statistically evaluate the sterilization process. The results show that it is possible to sterilize surfaces in a complex tube system with the use of gaseous hydrogen peroxide. A total microbial reduction of 6 log units was reached. PMID:15233253

  20. MINERALIZATION OF A SORBED POLYCYCLIC AROMATIC HYDROCARBON IN TWO SOILS USING CATALYZED HYDROGEN PEROXIDE. (R826163)

    EPA Science Inventory

    Hydrogen peroxide (H2O2) catalyzed by soluble iron or naturally occurring soil minerals, (i.e., modified Fenton's reagent) was investigated as a basis for mineralizing sorbed and NAPL-phase benzo[a]pyrene (BaP), a hydrophobic and toxic polycyclic a...

  1. Evaluation of a sporicidal peracetic acid/hydrogen peroxide-based daily disinfectant cleaner.

    PubMed

    Deshpande, Abhishek; Mana, Thriveen S C; Cadnum, Jennifer L; Jencson, Annette C; Sitzlar, Brett; Fertelli, Dennis; Hurless, Kelly; Kundrapu, Sirisha; Sunkesula, Venkata C K; Donskey, Curtis J

    2014-11-01

    OxyCide Daily Disinfectant Cleaner, a novel peracetic acid/hydrogen peroxide-based sporicidal disinfectant, was as effective as sodium hypochlorite for in vitro killing of Clostridium difficile spores, methicillin-resistant Staphylococcus aureus, and vancomcyin-resistant enterococci. OxyCide was minimally affected by organic load and was effective in reducing pathogen contamination in isolation rooms. PMID:25333438

  2. Uptake of methacrolein into aqueous solutions of sulfuric acid and hydrogen peroxide.

    PubMed

    Liu, Ze; Wu, Ling-Yan; Wang, Tian-He; Ge, Mao-Fa; Wang, Wei-Gang

    2012-01-12

    Multiphase acid-catalyzed oxidation by hydrogen peroxide has been suggested to be a potential route to secondary organic aerosol (SOA) formation from isoprene and its gas-phase oxidation products, but the kinetics and chemical mechanism remain largely uncertain. Here we report the first measurement of uptake of methacrolein into aqueous solutions of sulfuric acid and hydrogen peroxide in the temperature range of 253-293 K. The steady-state uptake coefficients were acquired and increased quickly with increasing sulfuric acid concentration and decreasing temperature. Propyne, acetone, and 2,3-dihydroxymethacrylic acid were suggested as the products. The chemical mechanism is proposed to be the oxidation of carbonyl group and C═C double bonds by peroxide hydrogen in acidic environment, which could explain the large content of polyhydroxyl compounds in atmospheric fine particles. These results indicate that multiphase acid-catalyzed oxidation of methacrolein by hydrogen peroxide can contribute to SOA mass in the atmosphere, especially in the upper troposphere.

  3. FIELD STUDY: IN SITU OXIDATION OF 1,4-DIOXANE WITH OZONE AND HYDROGEN PEROXIDE

    EPA Science Inventory

    A pilot-scale field evaluation is underway to assess the effectiveness of in situ oxidation (using ozone with and without hydrogen peroxide) for remediation of 1,4-dioxane and chlorinated volatile organic compounds in groundwater at the Cooper Drum Company Superfund Site located ...

  4. Haem oxygenase delays programmed cell death in wheat aleurone layers by modulation of hydrogen peroxide metabolism.

    PubMed

    Wu, Mingzhu; Huang, Jingjing; Xu, Sheng; Ling, Tengfang; Xie, Yanjie; Shen, Wenbiao

    2011-01-01

    Haem oxygenase-1 (HO-1) confers protection against a variety of oxidant-induced cell and tissue injury in animals and plants. In this report, it is confirmed that programmed cell death (PCD) in wheat aleurone layers is stimulated by GA and prevented by ABA. Meanwhile, HO activity and HO-1 protein expression exhibited lower levels in GA-treated layers, whereas the hydrogen peroxide (H(2)O(2)) content was apparently increased. The pharmacology approach illustrated that scavenging or accumulating H(2)O(2) either delayed or accelerated GA-induced PCD. Furthermore, pretreatment with the HO-1 specific inhibitor, zinc protoporphyrin IX (ZnPPIX), before exposure to GA, not only decreased HO activity but also accelerated GA-induced PCD significantly. The application of the HO-1 inducer, haematin, and the enzymatic reaction product of HO, carbon monoxide (CO) aqueous solution, both of which brought about a noticeable induction of HO expression, substantially prevented GA-induced PCD. These effects were reversed when ZnPPIX was added, suggesting that HO in vivo played a role in delaying PCD. Meanwhile, catalase (CAT) and ascorbate peroxidase (APX) activities or transcripts were enhanced by haematin, CO, or bilirubin (BR), the catalytic by-product of HO. This enhancement resulted in a decrease in H(2)O(2) production and a delay in PCD. In addition, the antioxidants butylated hydroxytoluene (BHT), dithiothreitol (DTT), and ascorbic acid (AsA) were able not only to delay PCD but also to mimic the effects of haematin and CO on HO up-regulation. Overall, the above results suggested that up-regulation of HO expression delays PCD through the down-regulation of H(2)O(2) production.

  5. Thermodynamic and kinetic considerations for the reaction of semiquinone radicals to form superoxide and hydrogen peroxide

    PubMed Central

    Song, Yang; Buettner, Garry R.

    2010-01-01

    The quinone/semiquinone/hydroquinone triad (Q/SQ•−/H2Q) represents a class of compounds that has great importance in a wide range of biological processes. The half-cell reduction potentials of these redox couples in aqueous solutions at neutral pH, E°′, provide a window to understanding the thermodynamic and kinetic characteristics of this triad and their associated chemistry and biochemistry in vivo. Substituents on the quinone ring can significantly influence the electron density “on the ring” and thus modify E°′ dramatically. E°′ of the quinone governs the reaction of semiquinone with dioxygen to form superoxide. At near-neutral pH the pKa's of the hydroquinone are outstanding indicators of the electron density in the aromatic ring of the members of these triads (electrophilicity) and thus are excellent tools to predict half-cell reduction potentials for both the one-electron and two-electron couples, which in turn allow estimates of rate constants for the reactions of these triads. For example, the higher the pKa's of H2Q, the lower the reduction potentials and the higher the rate constants for the reaction of SQ•− with dioxygen to form superoxide. However, hydroquinone autoxidation is controlled by the concentration of di-ionized hydroquinone; thus, the lower the pKa's the less stable H2Q to autoxidation. Catalysts, e.g., metals and quinone, can accelerate oxidation processes; by removing superoxide and increasing the rate of formation of quinone, superoxide dismutase can accelerate oxidation of hydroquinones and thereby increase the flux of hydrogen peroxide. The principal reactions of quinones are with nucleophiles via Michael addition, for example, with thiols and amines. The rate constants for these addition reactions are also related to E°′. Thus, pKa's of a hydroquinone and E°′ are central to the chemistry of these triads. PMID:20493944

  6. Baicalein Decreases Hydrogen Peroxide-Induced Damage to NG108-15 Cells via Upregulation of Nrf2.

    PubMed

    Yeh, Chao-Hung; Ma, Kuo-Hsing; Liu, Pei-Shan; Kuo, Jung-Kuei; Chueh, Sheau-Huei

    2015-08-01

    Baicalein is a flavonoid inhibitor of 12-lipoxygenase. Here, we investigated its effect on hydrogen peroxide-induced damage to NG108-15 cells. Hydrogen peroxide activated the mitochondrial apoptotic pathway, decreased Nrf2 expression, increased reactive oxygen species (ROS) levels, reduced viability, and increased cell death after 2-24 h treatment of NG108-15 cells. Co-treatment with hydrogen peroxide and baicalein completely suppressed the activation of mitochondrial apoptotic pathway by upregulating Nrf2 expression and reducing ROS stress and partially inhibited the effects on cell viability and cell death. Silencing of 12-lipoxygenase had a similar protective effect to baicalein on hydrogen peroxide-induced damage by blocking the hydrogen peroxide-induced decrease in Nrf2 expression and increase in ROS levels. Neither protective effect was altered by addition of 12-hydroxyeicosatetraenoic acid, the product of 12-lipoxygenase, suggesting that hydrogen peroxide induced damage via 12-lipoxygenase by another, as yet unknown, mechanism, rather than activating it. Co-treatment of cells with hydrogen peroxide and N-acetylcysteine or the Nrf2 inducer sulforaphane reduced hydrogen peroxide-induced damage in a similar fashion to baicalein, while the Nrf2 inhibitor retinoic acid blocked the protective effect of baicalein. Silencing Nrf2 also inhibited the protective effects of baicalein, sulforaphane, and N-acetylcysteine and resulted in high ROS levels, suggesting ROS elimination was mediated by Nrf2. Taken together our results suggest that baicalein protects cells from hydrogen peroxide-induced activation of the mitochondrial apoptotic pathway by upregulating Nrf2 and inhibiting 12-lipoxygenase to block the increase in ROS levels. Hydrogen peroxide also activates a second mitochondrial dysfunction independent death pathway which is resistant to baicalein.

  7. Inactivation of Escherichia coli by Polychromatic Simulated Sunlight: Evidence for and Implications of a Fenton Mechanism Involving Iron, Hydrogen Peroxide, and Superoxide

    PubMed Central

    2014-01-01

    Sunlight inactivation of Escherichia coli has previously been shown to accelerate in the presence of oxygen, exogenously added hydrogen peroxide, and bioavailable forms of exogenously added iron. In this study, mutants unable to effectively scavenge hydrogen peroxide or superoxide were found to be more sensitive to polychromatic simulated sunlight (without UVB wavelengths) than wild-type cells, while wild-type cells grown under low-iron conditions were less sensitive than cells grown in the presence of abundant iron. Furthermore, prior exposure to simulated sunlight was found to sensitize cells to subsequent hydrogen peroxide exposure in the dark, but this effect was attenuated for cells grown with low iron. Mutants deficient in recombination DNA repair were sensitized to simulated sunlight (without UVB wavelengths), but growth in the presence of iron chelators reduced the degree of sensitization conferred by this mutation. These findings support the hypothesis that hydrogen peroxide, superoxide, and intracellular iron all participate in the photoinactivation of E. coli and further suggest that the inactivation rate of enteric bacteria in the environment may be strongly dependent on iron availability and growth conditions. PMID:24271171

  8. Widespread sulfenic acid formation in tissues in response to hydrogen peroxide

    PubMed Central

    Saurin, Adrian T.; Neubert, Hendrik; Brennan, Jonathan P.; Eaton, Philip

    2004-01-01

    A principal product of the reaction between a protein cysteinyl thiol and hydrogen peroxide is a protein sulfenic acid. Because protein sulfenic acid formation is reversible, it provides a mechanism whereby changes in cellular hydrogen peroxide concentration may directly control protein function. We have developed methods for the detection and purification of proteins oxidized in this way. The methodology is based on the arsenite-specific reduction of protein sulfenic acid under denaturing conditions and their subsequent labeling with biotin–maleimide. Arsenite-dependent signal generation was fully blocked by pretreatment with dimedone, consistent with its reactivity with sulfenic acids to form a covalent adduct that is nonreducible by thiols. The biotin tag facilitates the detection of protein sulfenic acids on Western blots probed with streptavidin–horseradish peroxidase and also their purification by streptavidin–agarose. We have characterized protein sulfenic acid formation in isolated hearts subjected to hydrogen peroxide treatment. We have also purified and identified a number of the proteins that are oxidized in this way by using a proteomic approach. Using Western immunoblotting we demonstrated that a highly significant proportion of some individual proteins (68% of total in one case) form the sulfenic derivative. We conclude that protein sulfenic acids are widespread physiologically relevant posttranslational oxidative modifications that can be detected at basal levels in healthy tissue, and are elevated in response to hydrogen peroxide. These approaches may find widespread utility in the study of oxidative stress, particularly because hydrogen peroxide is used extensively in models of disease or redox signaling. PMID:15604151

  9. Radicular penetration of hydrogen peroxide during intra-coronal bleaching with various forms of sodium perborate.

    PubMed

    Weiger, R; Kuhn, A; Löst, C

    1994-11-01

    The development of external cervical root resorption following internal bleaching of discoloured pulpless teeth is associated with the use of hydrogen peroxide. The aim of the study was to determine radicular penetration of hydrogen peroxide following intracoronal bleaching with various forms of sodium perborate. 63 extracted human incisors were root filled and stained artificially. Standardized cementum defects were created on the mesial and distal aspects of the root directly below the cemento-enamel junction (CEJ). Using the walking bleach technique all teeth were bleached for a 6-day period, with replacement of the bleaching paste after days 1 and 3. Sodium perborate monohydrate (MH), trihydrate (TRH) or tetrahydrate (TH) was mixed with H2O2 or H2O and subsequently placed intracoronally 1 mm below the labial CEJ. The teeth were divided into six groups: I. MH + H2O2(30%) (n = 12); II. TRH + H2O2(30%) (n = 12); III. TH + H2O2(30%) (n = 12); IV. TH + H2O (n = 12); V. TH + H2O, gel (n = 12); VI. no bleaching paste (n = 3). At baseline and at days 1, 3 and 6 the amount of H2O2 taken up from the surrounding medium of each root was indirectly recorded and calculated as p.p.m. Almost all teeth of the experimental groups showed leakage of hydrogen peroxide compared to those of the control group. The radicular penetration of hydrogen peroxide was significantly higher in teeth of groups I and III than in those of groups IV and V (P < or = 0.001). In conclusion, the amount of hydrogen peroxide leakage depends, among other factors, on the form of sodium perborate used.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Proline dehydrogenase is essential for proline protection against hydrogen peroxide induced cell death

    PubMed Central

    Natarajan, Sathish Kumar; Zhu, Weidong; Liang, Xinwen; Zhang, Lu; Demers, Andrew J.; Zimmerman, Matthew C.; Simpson, Melanie A.; Becker, Donald F.

    2012-01-01

    Proline metabolism has an underlying role in apoptotic signaling that impacts tumorigenesis. Proline is oxidized to glutamate in the mitochondria with the rate limiting step catalyzed by proline dehydrogenase (PRODH). PRODH expression is inducible by p53 leading to increased proline oxidation, reactive oxygen species (ROS) formation, and induction of apoptosis. Paradoxical to its role in apoptosis, proline also protects cells against oxidative stress. Here we explore the mechanism of proline protection against hydrogen peroxide stress in melanoma WM35 cells. Treatment of WM35 cells with proline significantly increased cell viability, diminished oxidative damage of cellular lipids and proteins, and retained ATP and NADPH levels after exposure to hydrogen peroxide. Inhibition or siRNA-mediated knockdown of PRODH abolished proline protection against oxidative stress whereas knockdown of Δ1-pyrroline-5-carboxylate reductase, a key enzyme in proline biosynthesis, had no impact on proline protection. Potential linkages between proline metabolism and signaling pathways were explored. The combined inhibition of the mammalian target of rapamycin complex 1 (mTORC1) and mTORC2 eliminated proline protection. A significant increase in Akt activation was observed in proline treated cells after hydrogen peroxide stress along with a corresponding increase in the phosphorylation of the fork head transcription factor class O3a (FoxO3a). The role of PRODH in proline mediated protection was validated in the prostate carcinoma cell line, PC3. Knockdown of PRODH in PC3 cells attenuated phosphorylated levels of Akt and FoxO3a and decreased cell survival during hydrogen peroxide stress. The results provide evidence that PRODH is essential in proline protection against hydrogen peroxide mediated cell death and that proline/PRODH helps activate Akt in cancer cells. PMID:22796327

  11. Prostaglandins attenuate cardiac contractile dysfunction produced by free radical generation but not by hydrogen peroxide.

    PubMed

    Zimmer, K M; Karmazyn, M

    1997-11-01

    The aim of this study was to examine and compare the potential influence of cyclooxygenase or lipoxygenase derived metabolites of arachidonic acid on myocardial injury produced either by a free radical generating system consisting of purine plus xanthine oxidase or that produced by hydrogen peroxide. A free radical generating system consisting of purine (2.3 mM) and xanthine oxidase (10 U/L) as well as hydrogen peroxide (75 microM) produced significant functional changes in the absence of either significant deficits in high energy phosphates or ultrastructural damage. Prostaglandin F2 alpha (30 nM) significantly attenuated both the negative inotropic effect of purine plus xanthine oxidase as well as the ability of the free radical generator to elevate diastolic pressure. An identical concentration of prostaglandin 12 (prostacyclin) significantly reduced diastolic pressure elevation only and had no effect on contractile depression. The salutary effects of the two PGs occurred in the absence of any inhibitory influence on superoxide anion generation produced by the purine and xanthine oxidase reaction. None of prostaglandins modulated the response to hydrogen peroxide. In addition, neither prostaglandin E2 nor leukotrienes exerted any effect on changes produced by either type of oxidative stress. A 5 fold elevation in the concentrations of free radical generators or hydrogen peroxide produced extensive injury as characterized by a virtual total loss in contractility, 400% elevation in diastolic pressure, ultrastructural damage and significant depletions in high energy phosphate content. None of these effects were modulated by eicosanoid treatment. Our results therefore demonstrate a selective ability of both prostaglandin F2 alpha and to a lesser extent prostacyclin, to attenuate dysfunction produced by purine plus xanthine oxidase but not hydrogen peroxide. It is possible that these eicosanoids may represent endogenous protective factors under conditions of enhanced

  12. What are the sources of hydrogen peroxide production by heart mitochondria?

    PubMed Central

    Grivennikova, Vera G.; Kareyeva, Alexandra V.; Vinogradov, Andrei D.

    2010-01-01

    Coupled rat heart mitochondria produce externally hydrogen peroxide at the rates which correspond to about 0.8 and 0.3 per cent of the total oxygen consumption at State 4 with succinate and glutamate plus malate as the respiratory substrates, respectively. Stimulation of the respiratory activities by ADP (State 4–State 3 transition) decreases the succinate- and glutamate plus malate-supported H2O2 production 8- and 1.3-times, respectively. NH4+ strongly stimulates hydrogen peroxide formation with either substrate without any effect on State 4 and/or State 3 respiration. Rotenone-treated, alamethicin-permeabilized mitochondria catalyze NADH-supported H2O2 production at a rate about 10-fold higher than that seen in intact mitochondria under optimal (State 4 succinate-supported respiration in the presence of ammonium chloride) conditions. NADH-supported hydrogen peroxide production by the rotenone-treated mitochondria devoid of a permeability barrier for H2O2 diffusion by alamethicin treatment are only partially (~50%) sensitive to the Complex I NADH binding site-specific inhibitor, NADH-OH. The residual activity is strongly (~6-fold) stimulated by ammonium chloride. NAD+ inhibits both Complex I-mediated and ammonium-stimulated H2O2 production. In the absence of stimulatory ammonium about half of the total NADH-supported hydrogen peroxide production is catalyzed by Complex I. In the presence of ammonium about 90% of the total hydrogen peroxide production is catalyzed by matrix located, ammonium-dependent enzyme(s). PMID:20170624

  13. Reinvestigation of the Henry's law constant for hydrogen peroxide with temperature and acidity variation.

    PubMed

    Huang, Daoming; Chen, Zhongming

    2010-01-01

    Hydrogen peroxide is not only an important oxidant in itself; it also serves as both sink and temporary reservoir for other important oxidants including HOx (OH and HO2) radicals and O3 in the atmosphere. Its partitioning between gas and aqueous phases in the atmosphere, usually described by its Henry's law constant (K(H)), significantly influences its role in atmospheric processes. Large discrepancies between the K(H) values reported in previous work, however, have created uncertainty for atmospheric modelers. Based on our newly developed online instrumentation, we have re-determined the temperature and acidity dependence of K(H) for hydrogen peroxide at an air pressure of (0.960 +/- 0.013) atm (1 atm = 1.01325 x 10(5) Pa). The results indicated that the temperature dependence of K(H) for hydrogen peroxide fits to the Van't Hoff equation form, expressed as lnK(H) = a/T - b, and a = -deltaH/R, where K(H) is in M/atm (M is mol/L), T is in degrees Kelvin, R is the ideal gas constant, and deltaH is the standard heat of solution. For acidity dependence, results demonstrated that the K(H) value of hydrogen peroxide appeared to have no obvious dependence on decreasing pH level (from pH 7 to pH 1). Combining the dependence of both temperature and acidity, the obtained a and b were 7024 +/- 138 and 11.97 +/- 0.48, respectively, deltaH was (58.40 +/- 1.15) kJ/(K x mol), and the uncertainties represent sigma. Our determined K(H) values for hydrogen peroxide will therefore be of great use in atmospheric models. PMID:20617734

  14. Hydrogen peroxide mediates oxidant-dependent stimulation of arterial smooth muscle L-type calcium channels.

    PubMed

    Chaplin, Nathan L; Amberg, Gregory C

    2012-05-01

    Changes in calcium and redox homeostasis influence multiple cellular processes. Dysregulation of these signaling modalities is associated with pathology in cardiovascular, neuronal, endocrine, and other physiological systems. Calcium and oxidant signaling mechanisms are frequently inferred to be functionally related. To address and clarify this clinically relevant issue in the vasculature we tested the hypothesis that the ubiquitous reactive oxygen molecule hydrogen peroxide mediates oxidant-dependent stimulation of cerebral arterial smooth muscle L-type calcium channels. Using a combinatorial approach including intact arterial manipulations, electrophysiology, and total internal reflection fluorescence imaging, we found that application of physiological levels of hydrogen peroxide to isolated arterial smooth muscle cells increased localized calcium influx through L-type calcium channels. Similarly, oxidant-dependent stimulation of L-type calcium channels by the vasoconstrictor ANG II was abolished by intracellular application of catalase. Catalase also prevented ANG II from increasing localized subplasmalemmal sites of increased oxidation previously associated with colocalized calcium influx through L-type channels. Furthermore, catalase largely attenuated the contractile response of intact cerebral arterial segments to ANG II. In contrast, enhanced dismutation of superoxide to hydrogen peroxide with SOD had no effect on ANG II-dependent stimulation of L-type calcium channels. From these data we conclude that hydrogen peroxide is important for oxidant-dependent regulation of smooth muscle L-type calcium channels and arterial function. These data also support the emerging concept of hydrogen peroxide as a biologically relevant oxidant second messenger in multiple cell types with a diverse array of physiological functions.

  15. Localisation of hydrogen peroxide accumulation during Solanum tuberosum cv. Rywal hypersensitive response to Potato virus Y.

    PubMed

    Otulak, Katarzyna; Garbaczewska, Grazyna

    2010-06-01

    The reactive oxygen species hydrogen peroxide (H(2)O(2)) was detected cytochemically in Solanum tuberosum cv. Rywal tissues as a hypersensitive response (HR) 24 and 48 h after a Potato virus Y (PVY) infection. Hydrogen peroxide was detected in vivo by its reaction with 3.3-diaminobenzidine, producing a reddish-brown staining in contact with H(2)O(2). Hydrogen peroxide was detected in the necrotic area of the epidermal and mesophyll cells 24 and 48 h after the PVY infection. Highly localised accumulations of H(2)O(2) were found within xylem tracheary elements, and this was much more intensive than in non-infected leaves. Hydrogen peroxide was detected cytochemically in HR also by its reaction with cerium chloride, producing electron-dense deposits of cerium perhydroxides. Inoculation with PVY(NTN) and also PVY(N) Wi induced a rapid hypersensitive response during which highly localised accumulations of H(2)O(2) was detected in plant cell walls. The most intensive accumulation was present in the bordering cell walls of necrotic mesophyll cells and the adjacent non-necrotic mesophyll cells. Intensive electron-dense deposits of cerium perhydroxide were found along ER cistrenae and chloroplast envelopes connected with PVY particles. The precipitates of hydrogen peroxide were detected in the nuclear envelope and along tracheary elements, especially when virus particles were present inside. The intensive accumulation of H(2)O(2) at the early stages of potato-PVY interaction is consistent with its role as an antimicrobial agent and for this reason it has been regarded as a signalling molecule.

  16. Hydrogen peroxide and the evolution of oxygenic photosynthesis

    NASA Technical Reports Server (NTRS)

    Mckay, C. P.; Hartman, H.

    1991-01-01

    Possible pathways for the evolution of oxygenic photosynthesis in the early reducing atmosphere of the earth are discussed. It is suggested that the abiotic production of atmospheric oxidants could have provided a mechanism by which locally oxidizing conditions were sustained within spatially confined habitats thus removing the available reductants and forcing photosynthetic organisms to utilize water (rather than ferrous or sulfide ions) as the electron donor. It is argued that atmospheric H2O2 played the key role in inducing oxygenic photosynthesis, because, as peroxide concentrations local environments increased, primitive organisms would not only be faced with a loss of a reductant, but would be also forced to develop a biochemical apparatus (such as catalase) that would protect them against the products of oxygenic photosynthesis. This scenario allows for the early evolution of oxygenic photosynthesis at the time when global conditions were still anaerobic.

  17. Kinetic study of the reactions between chloramine disinfectants and hydrogen peroxide: temperature dependence and reaction mechanism.

    PubMed

    McKay, Garrett; Sjelin, Brittney; Chagnon, Matthew; Ishida, Kenneth P; Mezyk, Stephen P

    2013-09-01

    The temperature-dependent kinetics for the reaction between hydrogen peroxide and chloramine water disinfectants (NH2Cl, NHCl2, and NCl3) have been determined using stopped flow-UV/Vis spectrophotometry. Rate constants for the mono- and dichloramine-peroxide reaction were on the order of 10(-2)M(-1)s(-1) and 10(-5)M(-1)s(-1), respectively. The reaction of trichloramine with peroxide was negligibly slow compared to its thermal and photolytically-induced decomposition. Arrhenius expressions of ln(kH2O2-NH2Cl)=(17.3±1.5)-(51500±3700)/RT and ln(kH2O2-NHCl2)=(18.2±1.9)-(75800±5100)/RT were obtained for the mono- and dichloramine peroxide reaction over the temperature ranges 11.4-37.9 and 35.0-55.0°C, respectively. Both monochloramine and hydrogen peroxide were first-order in the rate-limiting kinetic step and concomitant measurements made using a chloride ion selective electrode showed that the chloride was produced quantitatively. These data will aid water utilities in predicting chloramine concentrations (and thus disinfection potential) throughout the water distribution system.

  18. Interpreting Heterogeneity in Response of Cells Expressing a Fluorescent Hydrogen Peroxide Biosensor.

    PubMed

    Huang, Beijing K; Ali, Sohail; Stein, Kassi T; Sikes, Hadley D

    2015-11-17

    Fluorescent, genetically encoded sensors of hydrogen peroxide have enabled visualization of perturbations to the intracellular level of this signaling molecule with subcellular and temporal resolution. Ratiometric sensors hold the additional promise of meaningful quantification of intracellular hydrogen peroxide levels as a function of time, a longstanding goal in the field of redox signaling. To date, studies that have connected the magnitudes of observed ratios with peroxide concentrations have either examined suspensions of cells or small numbers of adherent cells (∼10). In this work, we examined the response of all cells in several microscopic fields of view to an identical perturbation and observed a striking degree of heterogeneity of fluorescence ratios from individual cells. The expression level of the probe and phase within the cell cycle were each examined as potential contributors to the observed heterogeneity. Higher ratiometric responses correlated with greater expression levels of the probe and phase in the cell cycle were also shown to influence the magnitude of response. To aid in the interpretation of experimental observations, we incorporated the reaction of the reduced probe with peroxide and the reactions of the oxidized probe with glutathione and glutaredoxin into a larger kinetic model of peroxide metabolism. The predictions of the kinetic model suggest possible explanations for the experimental observations. This work highlights the importance of a systems-level approach to understanding the output of genetically encoded sensors that function via redox reactions involving thiol and disulfide groups.

  19. Ternary Composite of Hemin, Gold Nanoparticles and Graphene for Highly Efficient Decomposition of Hydrogen Peroxide

    PubMed Central

    Lv, Xincong; Weng, Jian

    2013-01-01

    A ternary composite of hemin, gold nanoparticles and graphene is prepared by a two-step process. Firstly, graphene-hemin composite is synthesized through π-π interaction and then hydrogen tetracholoroauric acid is reduced in situ by ascorbic acid. This ternary composite shows a higher catalytic activity for decomposition of hydrogen peroxide than that of three components alone or the mixture of three components. The Michaelis constant of this composite is 5.82 times lower and the maximal reaction velocity is 1.81 times higher than those of horseradish peroxidase, respectively. This composite also shows lower apparent activation energy than that of other catalysts. The excellently catalytic performance could be attributed to the fast electron transfer on the surface of graphene and the synergistic interaction of three components, which is further confirmed by electrochemical characterization. The ternary composite has been used to determine hydrogen peroxide in three real water samples with satisfactory results. PMID:24257652

  20. Multiassay analysis of the toxic potential of hydrogen peroxide on cultured neurons.

    PubMed

    Hohnholt, Michaela C; Blumrich, Eva M; Dringen, Ralf

    2015-07-01

    To clarify discrepancies in the literature on the adverse effects of hydrogen peroxide on neurons, this study investigated the application of this peroxide to cultured cerebellar granule neurons with six assays frequently used to test for viability. Cultured neurons efficiently cleared exogenous H2O2. Although viability was not affected by exposure to 10 µM hydrogen peroxide, an exposure to the peroxide in higher concentrations rapidly lowered, within 15 min, the cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium bromide (MTT) reduction capacity to 53% ± 1% (100 µM) and 31% ± 1% (1,000 µM) and the 3-amino-7-dimethylamino-2-methyl-phenazine hydrochloride (neutral red; NR) uptake to 84% ± 6% (100 µM) and 33% ± 1% (1,000 µM) of control cells. The release of glycolytically generated lactate was stopped within 30 min in neurons treated with 1,000 µM peroxide. In contrast, even hours after peroxide application, the cell morphology, the number of propidium iodide-positive cells, and the extracellular activity of the cytosolic enzyme lactate dehydrogenase (LDH) were not significantly altered. The rapid loss in MTT reduction and NR uptake after exposure of neurons to H2O2 for 5 or 15 min correlated well with a strongly compromised MTT reduction and a very high extracellular LDH activity observed after further incubation in peroxide-free medium for a total incubation period of 24 hr. These data demonstrate that cultured neurons do not recover from damage that is inflicted by a short exposure to H2O2 and that the rapid losses in the capacities of neurons for MTT reduction and NR uptake are good predictors of delayed cell damage.

  1. Advanced oxidation of natural organic matter using hydrogen peroxide and iron-coated pumice particles.

    PubMed

    Kitis, M; Kaplan, S S

    2007-08-01

    The oxidative removal of natural organic matter (NOM) from waters using hydrogen peroxide and iron-coated pumice particles as heterogeneous catalysts was investigated. Two NOM sources were tested: humic acid solution and a natural source water. Iron coated pumice removed about half of the dissolved organic carbon (DOC) concentration at a dose of 3000 mg l(-1) in 24 h by adsorption only. Original pumice and peroxide dosed together provided UV absorbance reductions as high as 49%, mainly due to the presence of metal oxides including Al(2)O(3), Fe(2)O(3) and TiO(2) in the natural pumice, which are known to catalyze the decomposition of peroxide forming strong oxidants. Coating the original pumice particles with iron oxides significantly enhanced the removal of NOM with peroxide. A strong linear correlation was found between iron contents of coated pumices and UV absorbance reductions. Peroxide consumption also correlated with UV absorbance reduction. Control experiments proved the effective coating and the stability of iron oxide species bound on pumice surfaces. Results overall indicated that in addition to adsorptive removal of NOM by metal oxides on pumice surfaces, surface reactions between iron oxides and peroxide result in the formation of strong oxidants, probably like hydroxyl radicals, which further oxidize both adsorbed NOM and remaining NOM in solution, similar to those in Fenton-like reactions.

  2. Real-time monitoring of hydrogen peroxide consumption in an oxidation reaction in molecular solvent and ionic liquids by a hydrogen peroxide electrochemical sensor.

    PubMed

    Sordi, Daniela; Arduini, Fabiana; Conte, Valeria; Moscone, Danila; Palleschi, Giuseppe

    2011-06-20

    An efficient electrochemical protocol to monitor hydrogen peroxide consumption during metal-catalyzed oxidation by using screen-printed electrodes modified with Prussian blue is presented. In particular, cyclooctene oxidation to cyclooctene oxide, catalyzed by a vanadium(V)-salophen complex (H(2)salophen=N,N'-o-phenylenebis(salicylideneimine)), in molecular and ionic media was tested. Initially, a protocol for batch analysis was developed for a monophasic system in acetonitrile, and subsequently, an in situ protocol was developed for a biphasic system of 1-butyl-3-methylimidazolium hexafluorophosphate/phosphate buffer. Calibration curves were performed in amperometric mode by applying -50 mV versus an Ag pseudo-reference. The calibration curve of hydrogen peroxide showed a linear correlation from 1 × 10(-6) up to 5 × 10(-3) mol L(-1) with satisfactory inter- and intra-electrode reproducibility (relative standard deviation (RSD) values of 5 and 13%, respectively, for the monophasic system and 11 and 13%, respectively, for the biphasic system). Kinetic studies to investigate the oxidation reaction for both the mono- and biphasic systems have been carried out in amperometric mode as well. Firstly, the decomposition of hydrogen peroxide was examined, which showed that, in 1-butyl-3-methylimidazolium hexafluorophosphate(,) it completely decomposed in 300 min, whereas in acetonitrile, in the same time frame, 20% of the initial amount was still active. In the presence of 1% of the catalyst the decomposition rate increased in both solvents. Finally, the complete oxidation of cyclooctene was followed and the effective conversion was determined. The developed protocols showed high reproducibility, with the advantage that the environmentally friendly biphasic system could also be recycled. The good analytical performance obtained, coupled with a short analysis time, the possibility of in-line automation and the use of ionic liquids instead of molecular solvents, made this

  3. Monte Carlo-quantum mechanics study of magnetic properties of hydrogen peroxide in liquid water.

    PubMed

    Caputo, María Cristina; Provasi, Patricio F; Benitez, Lucía; Georg, Herbert C; Canuto, Sylvio; Coutinho, Kaline

    2014-08-14

    A theoretical study of magnetic properties of hydrogen peroxide in water has been carried out by means of Monte Carlo simulation and quantum mechanics calculations. The solvent effects were evaluated in supermolecular structures generated by simulations in the NPT ensemble. The solute-solvent structure was analyzed in terms of radial distribution functions, and the solute-solvent hydrogen bonds were identified with geometric and energetic criteria. Approximately three water molecules are hydrogen bonded to H2O2 (0.6 and 0.8 in each hydrogen and oxygen atom, respectively, of the H2O2). Although, on average, both hydroxyls of the peroxide are equivalent, the distribution of hydrogen-bonded water molecules is highly asymmetric. Analyzing the statistics of the hydrogen bonds, we identify that only 34% of the configurations give symmetric distributions around the two hydroxyls of the H2O2 simultaneously. The magnetic shieldings and the indirect spin-spin coupling constants were calculated at the B3LYP/aug-cc-pVTZ and aug-cc-pVTZ-J computational level. We find that the solvent shields the oxygen and unshields the hydrogen atoms of the peroxide (+5.5 and -2.9 ppm, respectively), with large fluctuation from configuration to configuration in the oxygen case, an effect largely accounted for in terms of a single hydrogen bond with H2O2 as the proton donor. The most sensitive coupling in the presence of the solvent is observed to be the one-bond J(O,H).

  4. Influence of hydrogen peroxide bleaching gels on color, opacity, and fluorescence of composite resins.

    PubMed

    Torres, C R G; Ribeiro, C F; Bresciani, E; Borges, A B

    2012-01-01

    The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration. PMID:22433032

  5. Understanding the mechanism of DNA deactivation in ion therapy of cancer cells: hydrogen peroxide action*

    NASA Astrophysics Data System (ADS)

    Piatnytskyi, Dmytro V.; Zdorevskyi, Oleksiy O.; Perepelytsya, Sergiy M.; Volkov, Sergey N.

    2015-11-01

    Changes in the medium of biological cells under ion beam irradiation has been considered as a possible cause of cell function disruption in the living body. The interaction of hydrogen peroxide, a long-lived molecular product of water radiolysis, with active sites of DNA macromolecule was studied, and the formation of stable DNA-peroxide complexes was considered. The phosphate groups of the macromolecule backbone were picked out among the atomic groups of DNA double helix as a probable target for interaction with hydrogen peroxide molecules. Complexes consisting of combinations including: the DNA phosphate group, H2O2 and H2O molecules, and Na+ counterion, were considered. The counterions have been taken into consideration insofar as under the natural conditions they neutralise DNA sugar-phosphate backbone. The energy of the complexes have been determined by considering the electrostatic and the Van der Waals interactions within the framework of atom-atom potential functions. As a result, the stability of various configurations of molecular complexes was estimated. It was shown that DNA phosphate groups and counterions can form stable complexes with hydrogen peroxide molecules, which are as stable as the complexes with water molecules. It has been demonstrated that the formation of stable complexes of H2O2-Na+-PO4- may be detected experimentally by observing specific vibrations in the low-frequency Raman spectra. The interaction of H2O2 molecule with phosphate group of the double helix backbone can disrupt DNA biological function and induce the deactivation of the cell genetic apparatus. Thus, the production of hydrogen peroxide molecules in the nucleus of living cells can be considered as an additional mechanism by which high-energy ion beams destroy tumour cells during ion beam therapy. Contribution to the Topical Issue "COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy", edited by Andrey Solov'yov, Nigel Mason, Gustavo García, Eugene

  6. Expanding Hydrogen Peroxide Propulsion Test Capability at NASA's Stennis Space Center E-Complex

    NASA Technical Reports Server (NTRS)

    Jacks, Thomas E.; Beisler, Michele

    2003-01-01

    In recent years, the rocket propulsion test capability at NASA s John C. Stennis Space Center's (SSC) E-Complex has been enhanced to include facilitization for hydrogen peroxide (H2O2) based ground testing. In particular, the E-3 test stand has conducted numerous test projects that have been reported in the open literature. These include combustion devices as simple at small-scale catalyst beds, and larger devices such as ablative thrust chambers and a flight-type engine (AR2-3). Consequently, the NASA SSC test engineering and operations knowledge base and infrastructure have grown considerably in order to conduct safe H2O2 test operations with a variety of test articles at the component and engine level. Currently, the E-Complex has a test requirement for a hydrogen peroxide based stage test. This new development, with its unique set of requirements, has motivated the facilitization for hydrogen peroxide propellant use at the E-2 Cell 2 test position in addition to E-3. Since the E-2 Cell 2 test position was not originally designed as a hydrogen peroxide test stand, a facility modernization- improvement project was planned and implemented in FY 2002-03 to enable this vertical engine test stand to accommodate H2O2. This paper discusses the ongoing enhancement of E-Complex ground test capability, specifically at the E-3 stand (Cell 1 and Cell 2) and E-2 Cell 2 stand, that enable current and future customers considerable test flexibility and operability in conducting their peroxide based rocket R&D efforts.

  7. Recent Advances in Hydrogen Peroxide Propulsion Test Capability at NASA's Stennis Space Center E-Complex

    NASA Technical Reports Server (NTRS)

    Jacks, Thomas E.; Beisler, Michele

    2003-01-01

    In recent years, the rocket propulsion test capability at NASA's John C. Stennis Space Center's (SSC) E-Complex has been enhanced to include facilitization for hydrogen peroxide (H2O2) based ground testing. In particular, the E-3 test stand has conducted numerous test projects that have been reported in the open literature. These include combustion devices as simple as small-scale catalyst beds, and larger devices such as ablative thrust chambers and a flight-type engine (AR2-3). Consequently, the NASA SSC test engineering and operations knowledge base and infrastructure have grown considerably in order to conduct safe H2O2 test operations with a variety of test articles at the component and engine level. Currently, the E-Complex has a test requirement for a hydrogen peroxide based stage test. This new development, with its unique set of requirements, has motivated the facilitization for hydrogen peroxide propellant use at the E-2 Cell 2 test position in addition to E-3. Since the E-2 Cell 2 test position was not originally designed as a hydrogen peroxide test stand, a facility modernization-improvement project was planned and implemented in FY 2002-03 to enable this vertical engine test stand to accomodate H2O2. This paper discusses the ongoing enhancement of E-Complex ground test capability, specifically at the E-3 stand (Cell 1 and Cell 2) and E-2 Cell 2 stand, that enable current and future customers considerable test flexibility and operability in conducting their peroxide based rocket R&D efforts.

  8. Hydrogen peroxide and the evolution of oxygenic photosynthesis.

    PubMed

    McKay, C P; Hartman, H

    1991-01-01

    The early atmosphere of the Earth is considered to have been reducing (H2 rich) or neutral (CO2-N2). The present atmosphere by contrast is highly oxidizing (20% O2). The source of this oxygen is generally agreed to have been oxygenic photosynthesis, whereby organisms use water as the electron donor in the production of organic matter, liberating oxygen into the atmosphere. A major question in the evolution of life is how oxygenic photosynthesis could have evolved under anoxic conditions--and also when this capability evolved. It seems unlikely that water would be employed as the electron donor in anoxic environments that were rich in reducing agents such as ferrous or sulfide ions which could play that role. The abiotic production of atmospheric oxidants could have provided a mechanism by which locally oxidizing conditions were sustained within spatially confined habitats thus removing the available reductants and forcing photosynthetic organisms to utilize water as the electron donor. We suggest that atmospheric H2O2 played the key role in inducing oxygenic photosynthesis because as peroxide increased in a local environment, organisms would not only be faced with a loss of reductant, but they would also be pressed to develop the biochemical apparatus (e.g., catalase) that would ultimately be needed to protect against the products of oxygenic photosynthesis. This scenario allows for the early evolution of oxygenic photosynthesis while global conditions were still anaerobic.

  9. Flow injection determination of hydrogen peroxide using catalytic effect of cobalt(II) ion on a dye formation reaction.

    PubMed

    Kurihara, Makoto; Muramatsu, Miyuki; Yamada, Mari; Kitamura, Naoya

    2012-07-15

    A novel flow injection photometric method was developed for the determination of hydrogen peroxide in rainwater. This method is based on a cobalt(II)-catalyzed oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone (MBTH) with N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline (DAOS) as a modified Trinder's reagent to produce intensely colored dye (λ(max)=530nm) in the presence of hydrogen peroxide at pH 8.4. In this method, 1,2-dihydroxy-3,5-benzenedisulfonic acid (Tiron) acted as an activator for the cobalt(II)-catalyzed reaction and effectively increased the peak height for hydrogen peroxide. The linear calibration graphs were obtained in the hydrogen peroxide concentration range 5×10(-8) to 2.2×10(-6)mol dm(-3) at a sampling rate of 20h(-1). The relative standard deviations for ten determinations of 2.2×10(-6) and 2×10(-7)mol dm(-3) hydrogen peroxide were 1.1% and 3.7%, respectively. The proposed method was successfully applied to the determination of hydrogen peroxide in rainwater samples and the analytical results agreed fairly well with the results obtained by different two reference methods; peroxidase method and hydrogen peroxide electrode method.

  10. Flow-injection determination of hydrogen peroxide based on fluorescence quenching of chromotropic acid catalyzed with Fe(II).

    PubMed

    Li, Zhen Hai; Li, Dong Hao; Oshita, Koji; Motomizu, Shoji

    2010-09-15

    Flow-injection analysis system (FIA system), which was based on Fe(II)-catalyzed oxidation of chromotropic acid with hydrogen peroxide, was developed for the determination of hydrogen peroxide. The chromotropic acid has a fluorescence measured at lambda(em)=440 nm (emission wavelength) with lambda(ex)=235 nm (excitation wavelength), and the fluorescence intensity at lambda(em)=440 nm quietly decreased in the presence of hydrogen peroxide and Fe(II), which was caused by Fe(II)-catalyzed oxidation of chromotropic acid with hydrogen peroxide. By measuring the difference of fluorescence intensity, hydrogen peroxide (1.0 x 10(-8)-1.0 x 10(-3) mol L(-1)) could be determined by the proposed FIA system, whose analytical throughput was 40 samples h(-1). The relative standard deviation (RSD) was 1.03% (n=10) for 4.0 x 10(-8) mol L(-1) hydrogen peroxide. The proposed FIA technique could be applied to the determination of hydrogen peroxide in rain water samples.

  11. Evaluation of the toxicity and efficacy of hydrogen peroxide treatments on eggs of warm and cool water fishes

    USGS Publications Warehouse

    Rach, J.J.; Gaikowski, M.P.; Howe, G.E.; Schreier, T.M.

    1998-01-01

    The use of hydrogen peroxide in aquaculture is growing and there is a need to develop fundamental guidelines to effectively treat diseased fish. The safety (toxicity) of hydrogen peroxide treatments was determined on eggs of representative warm- and coolwater fish species. Eggs of northern pike (Esox lucius), walleye (Stizostedion vitreum), yellow perch (Pel ca flavescens), white sucker (Catostomus commersoni), lake sturgeon (Acipenser fulvescens), paddlefish (Polyodon spathula), common carp (Cyprinus carpio), and channel catfish (Ictalurus punctatus) were cultured in egg jars or aquaria. Treatments were initiated with non-eyed eggs and continued until all viable eggs had hatched. Eggs were treated daily for 15 min Monday through Friday with either 0, 500, 1000, 3000, or 6000 mu l l(-1) of hydrogen peroxide. For all species, the mean percent hatch was greater in eggs treated with 1000 mu l l(-1) hydrogen peroxide for 15 min than in the untreated controls. Common carp, lake sturgeon, and paddlefish were the least sensitive to hydrogen peroxide with percent hatch ranging from 40 to 48% in the 6000 mu l l(-1) hydrogen peroxide treatment. Fungal infections reduced or eliminated the hatch in most controls whereas nearly all treated eggs remained free of infection; hydrogen peroxide inhibited fungal infections on fish eggs. (C) 1998 Elsevier Science B.V. All rights reserved.

  12. Efficacy of hydrogen peroxide in controlling mortality associated with saprolegniasis on walleye, white sucker, and paddlefish eggs

    USGS Publications Warehouse

    Gaikowski, M.P.; Rach, J.J.; Drobish, M.; Hamilton, J.; Harder, T.; Lee, L.A.; Moen, C.; Moore, A.

    2003-01-01

    The efficacy of hydrogen peroxide in controlling saprolegniasis on eggs of walleye Stizostedion vitreum, white sucker Catostomus commersoni, and paddlefish Polyodon spathula was evaluated at four private, state, and federal production hatcheries participating in an Investigational New Animal Drug efficacy study (experiment 1; walleyes) and in a laboratory-based miniature egg jar incubation system (experiment 2; walleyes, white suckers, and paddlefish). Naturally occurring fungal infestations (saprolegniasis) were observed on eggs in both experiments. Confirmatory diagnosis of infested eggs from one hatchery in experiment 1 identified the pathogen as Saprolegnia parasitica. During experiment 1, eggs were treated daily for 15 min with either 0, 500, or 750 mg/L of hydrogen peroxide, and one trial compared a 500-mg/L hydrogen peroxide treatment with a formalin treatment at 1,667 mg/L. Saprolegniasis infestation was observed in control egg jars, whereas treatment with either formalin or hydrogen peroxide virtually eliminated the infestation. Hydrogen peroxide treatments of 500 mg/L either increased egg hatch or were as effective as physical removal of infested eggs in controlling mortality. Although treatment with formalin at 1,667 mg/L significantly increased the percent eye-up of walleye eggs compared with that of those treated with hydrogen peroxide at 500 mg/L, the difference was only 1.9-2.6%. In experiment 2, noneyed eggs were treated for 15 min every other day with 0, 283, 565, or 1,130 mg/L of hydrogen peroxide until the viable eggs hatched. Saprolegniasis infestation engulfed most control eggs, whereas infestation of treated eggs was either reduced or not visible. Hydrogen peroxide significantly increased egg hatch for all three species tested in experiment 2. Although hydrogen peroxide treatments as low as 283 mg/L significantly increased walleye and white sucker hatch, treatments between 500 and 1,000 mg/L are more likely to be effective in production egg

  13. Endothelial activation by hydrogen peroxide. Selective increases of intercellular adhesion molecule-1 and major histocompatibility complex class I.

    PubMed Central

    Bradley, J. R.; Johnson, D. R.; Pober, J. S.

    1993-01-01

    Products of activated leukocytes may alter vascular endothelial cell (EC) function. For example, ECs respond to leukocyte-derived cytokines, such as tumor necrosis factor (TNF) or interleukin-1, by reversibly altering levels of expression of specific gene products that promote inflammation. In contrast, hydrogen peroxide, a product of TNF-activated neutrophils, can produce irreversible EC injury and death. In this study, we have investigated the effects of subinjurious concentrations of hydrogen peroxide on EC inflammatory functions. Treatment with 50 to 100 mumol/L hydrogen peroxide selectively increases surface expression of intercellular adhesion molecule-1 and major histocompatibility complex class I, but not endothelial leukocyte adhesion molecule-1 (also known as E-selectin), vascular cell adhesion molecule-1, or gp96, a constitutively expressed EC surface protein. Increased major histocompatibility complex class I and intercellular adhesion molecule-1 surface expression is associated with specifically increased messenger RNA levels, suggesting selective endothelial gene activation. Hydrogen peroxide does not activate the transcription factor Nuclear Factor kappa B, an important mediator of TNF-induced gene expression. Co-treatment with hydrogen peroxide inhibits TNF-induced gene expression at 4 hours, an effect which can be attributed to reversible inhibition of TNF binding to EC surface receptors. Hydrogen peroxide also antagonizes the actions of interleukin-1. At 24 hours, TNF and hydrogen peroxide produce, at most, additive increases in intercellular adhesion molecule-1 and major histocompatibility complex class I. These results suggest that subinjurious concentrations of hydrogen peroxide can activate endothelium and that the effects of hydrogen peroxide on ECs differ from those of inflammatory cytokines. Images Figure 3 Figure 4 Figure 5 PMID:8098585

  14. Sterilization of hydrogen peroxide resistant bacterial spores with stabilized chlorine dioxide.

    PubMed

    Friedline, Anthony; Zachariah, Malcolm; Middaugh, Amy; Heiser, Matt; Khanna, Neeraj; Vaishampayan, Parag; Rice, Charles V

    2015-01-01

    Bacillus pumilus SAFR-032 spores isolated from a clean room environment are known to exhibit enhanced resistance to peroxide, desiccation, UV radiation and chemical disinfection than other spore-forming bacteria. The survival of B. pumilus SAFR-032 spores to standard clean room sterilization practices requires development of more stringent disinfection agents. Here, we report the effects of a stabilized chlorine dioxide-based biocidal agent against spores of B. pumilus SAFR-032 and Bacillus subtilis ATCC 6051. Viability was determined via CFU measurement after exposure. Chlorine dioxide demonstrated efficacy towards sterilization of spores of B. pumilus SAFR-032 equivalent or better than exposure to hydrogen peroxide. These results indicate efficacy of chlorine dioxide delivered through a stabilized chlorine dioxide product as a means of sterilization of peroxide- and UV-resistant spores.

  15. Absolute rate constant of the reaction between chlorine /2P/ atoms and hydrogen peroxide from 298 to 424 K

    NASA Technical Reports Server (NTRS)

    Keyser, L. F.

    1980-01-01

    The absolute rate constant of the reaction between chlorine (2P) atoms and hydrogen peroxide was determined from 298 to 424 K, using the discharge flow resonance fluorescence technique. Pseudo-first-order conditions were used with hydrogen peroxide in large excess. A fast flow-sampling procedure limited hydrogen peroxide decomposition to less than 5% over the temperature range studied. At 298 K, the rate constant is (4.1 plus or minus 0.2) x 10 to the minus 13th cu cm/molecule-sec.

  16. Antibacterial Properties and Mechanism of Activity of a Novel Silver-Stabilized Hydrogen Peroxide

    PubMed Central

    Martin, Nancy L.; Bass, Paul; Liss, Steven N.

    2015-01-01

    Huwa-San peroxide (hydrogen peroxide; HSP) is a NSF Standard 60 (maximum 8mg/L-1) new generation peroxide stabilized with ionic silver suitable for continuous disinfection of potable water. Experiments were undertaken to examine the mechanism of HSP against planktonic and biofilm cultures of indicator bacterial strains. Contact/kill time (CT) relationships that achieve effective control were explored to determine the potential utility in primary disinfection. Inhibitory assays were conducted using both nutrient rich media and a medium based on synthetic wastewater. Assays were compared for exposures to three disinfectants (HSP, laboratory grade hydrogen peroxide (HP) and sodium hypochlorite) at concentrations of 20 ppm (therefore at 2.5 and 5 times the NSF limit for HP and sodium hypochlorite, respectively) and at pH 7.0 and 8.5 in dechlorinated tap water. HSP was found to be more or equally effective as hypochlorite or HP. Results from CT assays comparing HSP and HP at different bacterial concentrations with neutralization of residual peroxide with catalase suggested that at a high bacterial concentration HSP, but not HP, was protected from catalase degradation possibly through sequestration by bacterial cells. Consistent with this hypothesis, at a low bacterial cell density residual HSP was more effectively neutralized as less HSP was associated with bacteria and therefore accessible to catalase. Silver in HSP may facilitate this association through electrostatic interactions at the cell surface. This was supported by experiments where the addition of mono (K+) and divalent (Ca+2) cations (0.005-0.05M) reduced the killing efficacy of HSP but not HP. Experiments designed to distinguish any inhibitory effect of silver from that of peroxide in HSP were carried out by monitoring the metabolic activity of established P. aeruginosa PAO1 biofilms. Concentrations of 70-500 ppm HSP had a pronounced effect on metabolic activity while the equivalent concentrations of ionic

  17. Antibacterial Properties and Mechanism of Activity of a Novel Silver-Stabilized Hydrogen Peroxide.

    PubMed

    Martin, Nancy L; Bass, Paul; Liss, Steven N

    2015-01-01

    Huwa-San peroxide (hydrogen peroxide; HSP) is a NSF Standard 60 (maximum 8 mg/L(-1)) new generation peroxide stabilized with ionic silver suitable for continuous disinfection of potable water. Experiments were undertaken to examine the mechanism of HSP against planktonic and biofilm cultures of indicator bacterial strains. Contact/kill time (CT) relationships that achieve effective control were explored to determine the potential utility in primary disinfection. Inhibitory assays were conducted using both nutrient rich media and a medium based on synthetic wastewater. Assays were compared for exposures to three disinfectants (HSP, laboratory grade hydrogen peroxide (HP) and sodium hypochlorite) at concentrations of 20 ppm (therefore at 2.5 and 5 times the NSF limit for HP and sodium hypochlorite, respectively) and at pH 7.0 and 8.5 in dechlorinated tap water. HSP was found to be more or equally effective as hypochlorite or HP. Results from CT assays comparing HSP and HP at different bacterial concentrations with neutralization of residual peroxide with catalase suggested that at a high bacterial concentration HSP, but not HP, was protected from catalase degradation possibly through sequestration by bacterial cells. Consistent with this hypothesis, at a low bacterial cell density residual HSP was more effectively neutralized as less HSP was associated with bacteria and therefore accessible to catalase. Silver in HSP may facilitate this association through electrostatic interactions at the cell surface. This was supported by experiments where the addition of mono (K(+)) and divalent (Ca(+2)) cations (0.005-0.05M) reduced the killing efficacy of HSP but not HP. Experiments designed to distinguish any inhibitory effect of silver from that of peroxide in HSP were carried out by monitoring the metabolic activity of established P. aeruginosa PAO1 biofilms. Concentrations of 70-500 ppm HSP had a pronounced effect on metabolic activity while the equivalent concentrations of

  18. Antibacterial Properties and Mechanism of Activity of a Novel Silver-Stabilized Hydrogen Peroxide.

    PubMed

    Martin, Nancy L; Bass, Paul; Liss, Steven N

    2015-01-01

    Huwa-San peroxide (hydrogen peroxide; HSP) is a NSF Standard 60 (maximum 8 mg/L(-1)) new generation peroxide stabilized with ionic silver suitable for continuous disinfection of potable water. Experiments were undertaken to examine the mechanism of HSP against planktonic and biofilm cultures of indicator bacterial strains. Contact/kill time (CT) relationships that achieve effective control were explored to determine the potential utility in primary disinfection. Inhibitory assays were conducted using both nutrient rich media and a medium based on synthetic wastewater. Assays were compared for exposures to three disinfectants (HSP, laboratory grade hydrogen peroxide (HP) and sodium hypochlorite) at concentrations of 20 ppm (therefore at 2.5 and 5 times the NSF limit for HP and sodium hypochlorite, respectively) and at pH 7.0 and 8.5 in dechlorinated tap water. HSP was found to be more or equally effective as hypochlorite or HP. Results from CT assays comparing HSP and HP at different bacterial concentrations with neutralization of residual peroxide with catalase suggested that at a high bacterial concentration HSP, but not HP, was protected from catalase degradation possibly through sequestration by bacterial cells. Consistent with this hypothesis, at a low bacterial cell density residual HSP was more effectively neutralized as less HSP was associated with bacteria and therefore accessible to catalase. Silver in HSP may facilitate this association through electrostatic interactions at the cell surface. This was supported by experiments where the addition of mono (K(+)) and divalent (Ca(+2)) cations (0.005-0.05M) reduced the killing efficacy of HSP but not HP. Experiments designed to distinguish any inhibitory effect of silver from that of peroxide in HSP were carried out by monitoring the metabolic activity of established P. aeruginosa PAO1 biofilms. Concentrations of 70-500 ppm HSP had a pronounced effect on metabolic activity while the equivalent concentrations of

  19. Glutathione Peroxidase 7 Utilizes Hydrogen Peroxide Generated by Ero1α to Promote Oxidative Protein Folding

    PubMed Central

    Zhang, Lihui; Niu, Yingbo; Sitia, Roberto

    2014-01-01

    Abstract Aims: Ero1 flavoproteins catalyze oxidative folding in the endoplasmic reticulum (ER), consuming oxygen and generating hydrogen peroxide (H2O2). The ER-localized glutathione peroxidase 7 (GPx7) shows protein disulfide isomerase (PDI)-dependent peroxidase activity in vitro. Our work aims at identifying the physiological role of GPx7 in the Ero1α/PDI oxidative folding pathway and at dissecting the reaction mechanisms of GPx7. Results: Our data show that GPx7 can utilize Ero1α-produced H2O2 to accelerate oxidative folding of substrates both in vitro and in vivo. H2O2 oxidizes Cys57 of GPx7 to sulfenic acid, which can be resolved by Cys86 to form an intramolecular disulfide bond. Both the disulfide form and sulfenic acid form of GPx7 can oxidize PDI for catalyzing oxidative folding. GPx7 prefers to interact with the a domain of PDI, and intramolecular cooperation between the two redox-active sites of PDI increases the activity of the Ero1α/GPx7/PDI triad. Innovation: Our in vitro and in vivo evidence provides mechanistic insights into how cells consume potentially harmful H2O2 while optimizing oxidative protein folding via the Ero1α/GPx7/PDI triad. Cys57 can promote PDI oxidation in two ways, and Cys86 emerges as a novel noncanonical resolving cysteine. Conclusion: GPx7 promotes oxidative protein folding, directly utilizing Ero1α-generated H2O2 in the early secretory compartment. Thus, the Ero1α/GPx7/PDI triad generates two disulfide bonds and two H2O molecules at the expense of a single O2 molecule. Antioxid. Redox Signal. 20, 545–556. PMID:23919619

  20. Synthetic multivalent DNAzymes for enhanced hydrogen peroxide catalysis and sensitive colorimetric glucose detection.

    PubMed

    Yang, Deng-Kai; Kuo, Chia-Jung; Chen, Lin-Chi

    2015-01-26

    A peroxidase-mimic DNAzyme is a G-quadruplex (G4) DNA-hemin complex, in which the G4-DNA resembles an apoenzyme, and hemin is the cofactor for hydrogen peroxide (H2O2) catalysis. Twenty-one-mer CatG4 is a well-proven G4-DNA as well as a hemin-binding aptamer for constituting a DNAzyme. This work studied if a multivalent DNAzyme with accelerated catalysis could be constructed using a multimeric CatG4 with hemin. We compared CatG4 monomer, dimer, trimer, and tetramer, which were prepared by custom oligo synthesis, for G4 structure formation. According to circular dichroism (CD) analysis, we found that a CatG4 multimer exhibited more active G4 conformation than the sum effect of equal-number CatG4 monomers. However, the DNAzyme kinetics was not improved monotonically along with the subunit number of a multimeric CatG4. It was the trivalent DNAzyme, trimeric CatG4:hemin, resulting in the rapidest H2O2 catalysis instead of a tetravalent one. We discovered that the trivalent DNAzyme's highest catalytic rate was correlated to its most stable hemin-binding G4 structure, evidenced by CD melting temperature analysis. Finally, a trivalent DNAzyme-based colorimetric glucose assay with a detection limit as low as 10 μM was demonstrated, and this assay did not need adenosine 5'-tri-phosphate disodium salt hydrate (ATP) as a DNAzyme boosting agent. PMID:25542363

  1. Reduction of combustion emissions using hydrogen peroxide in a pilot scale combustion chamber

    SciTech Connect

    Martinez, A.I.; Corredor, L.F.; Tamara, W.

    1997-12-31

    A hydrogen peroxide injection system was designed and installed in the stack of a 5,274 million J/hr industrial pilot plant scale combustion chamber using natural gas as fuel. The concentration of peroxide in the gas stream was precisely controlled by continuous injection using an electromagnetic dosage pump, the liquid 50% peroxide solution was finely dispersed into the gases by a water cooled custom designed delivery system with a spray nozzle at the tip. Residence times between 0.1 and 1.8 seconds and concentrations of H{sub 2}O{sub 2} between 280 ppm and 4,000 ppm were used during the test runs. CEMS for total hydrocarbons, carbon monoxide, nitrogen oxides, as well as an ultrasonic gas flow monitor were used to measure the effect of hydrogen peroxide in reducing the emissions of these pollutants. Destruction removal efficiencies between 25% and 100% were observed for hydrocarbons, and concentrations of CO, as well as NO{sub x}. were reduced about 50%. The results indicate that this labscale proved technology yields similar results in reducing combustion emissions in pilot applications, and also a reliable injection system has been developed and tested successfully.

  2. Speeding up solar disinfection (SODIS): effects of hydrogen peroxide, temperature, pH, and copper plus ascorbate on the photoinactivation of E. coli.

    PubMed

    Fisher, Michael B; Keenan, Christina R; Nelson, Kara L; Voelker, Bettina M

    2008-03-01

    Solar disinfection, or SODIS, shows tremendous promise for point-of-use drinking water treatment in developing countries, but can require 48 h or more for adequate disinfection in cloudy weather. In this research, we show that a number of low-cost additives are capable of accelerating SODIS. These additives included 100-1000 muM hydrogen peroxide, both at room temperature and at elevated temperatures, 0.5 - 1% lemon and lime juice, and copper metal or aqueous copper plus ascorbate, with or without hydrogen peroxide. Laboratory and field experiments indicated that additives might make SODIS more rapid and effective in both sunny and cloudy weather, developments that could help make the technology more effective and acceptable to users.

  3. Formation of water-soluble soybean polysaccharides from spent flakes by hydrogen peroxide treatment.

    PubMed

    Pierce, Brian C; Wichmann, Jesper; Tran, Tam H; Cheetamun, Roshan; Bacic, Antony; Meyer, Anne S

    2016-06-25

    In this paper we propose a novel chemical process for the generation of water-soluble polysaccharides from soy spent flake, a by-product of the soy food industry. This process entails treatment of spent flake with hydrogen peroxide at an elevated temperature, resulting in the release of more than 70% of the original insoluble material as high molar mass soluble polysaccharides. A design of experiment was used to quantify the effects of pH, reaction time, and hydrogen peroxide concentration on the reaction yield, average molar mass, and free monosaccharides generated. The resulting product is low in protein, fat, and minerals and contains predominantly water-soluble polysaccharides of high molar mass, including arabinan, type I arabinogalactan, homogalacturonan, xyloglucan, rhamnogalacturonan, and (glucurono)arabinoxylan. This treatment provides a straightforward approach for generation of soluble soy polysaccharides and opens a new range of opportunities for this abundant and underutilized material in future research and industrial applications. PMID:27083842

  4. First-principles simulations of hydrogen peroxide formation catalyzed by small neutral gold clusters.

    PubMed

    Kacprzak, Katarzyna A; Akola, Jaakko; Häkkinen, Hannu

    2009-08-14

    Energetics and dynamical pathways for hydrogen peroxide formation from H(2) and O(2) bound to neutral gold dimers and tetramers have been investigated by applying several strategies: T = 0 K geometry optimizations, constrained Car-Parrinello molecular dynamics simulations at T = 300 K and metadynamics at T = 300 K. The competing reaction channels for water and hydrogen peroxide formation have been found and characterized. In each case, the reaction barriers for Au cluster catalyzed proton transfer are less than 1 eV. Water formation is a competitive reaction channel, and the relative weight of H(2)O and H(2)O(2) products may depend on the chosen Au cluster size. Dynamic simulations demonstrate the significance of the geometric fluxionality of small catalytic Au clusters. These results indicate that neutral Au clusters could work as catalysts in aerobic H(2)O(2) formation in ambient conditions. PMID:19809667

  5. Measuring hydrogen peroxide reduction using a robust, inexpensive, and sensitive method.

    PubMed

    Hyland, Ryan A; Rogers, Peter J; Higgins, Vincent J; Myers, Simon; Coorssen, Jens R

    2012-01-01

    Here, we report an improved method to analyze antioxidant activity using the europium tetracycline assay developed by Duerkop and Wolfbeis (J Fluor 15(5):755-761, 2005). The europium tetracycline hydrogen peroxide reduction assay (EHRA) accurately measures antioxidant activity based on hydrogen peroxide scavenging. Several known antioxidant compounds were assessed with the EHRA and a stoichiometric relationship between the number of oxidant molecules trapped per molecule of antioxidant was identified. Various extracts of hops were also tested to validate this method for use with natural extracts; water extraction yielded the highest level of antioxidant activity. Hop leaves were shown to be a better source of antioxidants relative to the traditional hop cones. The data also indicate that the EHRA may serve to breach the hydrophilic/lipophilic gap in antioxidant screening as the europium tetracycline probe is effective in many solvents. The EHRA thus provides a robust and inexpensive measure of antioxidant activity. PMID:23997833

  6. Decomposition Kinetics of Hydrogen Peroxide: Novel Lab Experiments Employing Computer Technology

    NASA Astrophysics Data System (ADS)

    Abramovitch, Dorota A.; Cunningham, Latrice K.; Litwer, Mitchell R.

    2003-07-01

    The quantitative catalytic decomposition of hydrogen peroxide has been used in many general chemistry experiments. The typical procedure involves measuring the volume of oxygen generated in the reaction under constant pressure using a displacement method and calculating the necessary data. A pressure sensor interfaced with a computer using LabWorks II software allowed us to modify this reaction and to measure the change in pressure, at constant volume. Since the software allows the collection and display of real-time data and the ability to import the data to Excel, we re-examined the kinetics of this reaction. Using different concentrations of hydrogen peroxide and catalase enzyme and graphing initial concentrations versus initial rates, we determined the rate and the order of the decomposition.

  7. Methods and apparatus for the on-site production of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Buschmann, Wayne E. (Inventor); James, Patrick I. (Inventor)

    2010-01-01

    Methods, apparatus, and applications for the on-site production of hydrogen peroxide are described. An embodiment of the apparatus comprises at least one anolyte chamber coupled to at least one anode, at least one catholyte chamber, wherein the at least one catholyte chamber is coupled to at least one cathode, at least one anode membrane and at least one cathode membrane, wherein the anode membrane is adjacent to the at least one anode, wherein the cathode membrane is adjacent to the at least one cathode, at least one central chamber disposed between the at least one anolyte chamber and the at least one catholyte chamber. Hydrogen peroxide is produced by reduction of an oxygen-containing gas at the cathode.

  8. Effects of Microstructure of Carbon Nanofibers for Amperometric Detection of Hydrogen Peroxide

    SciTech Connect

    Li, Zhizhou; Cui, Xiaoli; Zheng, Junsheng; Wang, Qingfei; Lin, Yuehe

    2007-08-10

    Carbon nanofibers (CNFs) with different microstructures, including platelet-carbon nanofibers (PCNFs), fish-bone-carbon nanofibers (FCNFs), and tube-carbon nanofibers (TCNFs), were synthesized, characterized, and evaluated for electrochemical sensing of hydrogen peroxide. The CNFs studied here can show several microstructures in which various stacked morphologies and their sizes and graphite-layer ordering can be well controlled. Glassy carbon (GC) electrodes modified by CNFs were fabricated and compared for amperometric detection of hydrogen peroxide. Sensors of PCNFs/GC, FCNFs/GC, and TCNFs/GC were used in the amperometric detection of H2O2 in a solution of 0.05 M phosphate buffered saline solution (pH 7.4).

  9. Uranium- and thorium-doped graphene for efficient oxygen and hydrogen peroxide reduction.

    PubMed

    Sofer, Zdeněk; Jankovský, Ondřej; Šimek, Petr; Klímová, Kateřina; Macková, Anna; Pumera, Martin

    2014-07-22

    Oxygen reduction and hydrogen peroxide reduction are technologically important reactions in the fields of energy generation and sensing. Metal-doped graphenes, where metal serves as the catalytic center and graphene as the high area conductor, have been used as electrocatalysts for such applications. In this paper, we investigated the use of uranium-graphene and thorium-graphene hybrids prepared by a simple and scalable method. The hybrids were synthesized by the thermal exfoliation of either uranium- or thorium-doped graphene oxide in various atmospheres. The synthesized graphene hybrids were characterized by high-resolution XPS, SEM, SEM-EDS, combustible elemental analysis, and Raman spectroscopy. The influence of dopant and exfoliation atmosphere on electrocatalytic activity was determined by electrochemical measurements. Both hybrids exhibited excellent electrocatalytic properties toward oxygen and hydrogen peroxide reduction, suggesting that actinide-based graphene hybrids have enormous potential for use in energy conversion and sensing devices.

  10. Effect of hydrogen peroxide and camellia sinensis extract on reduction of oxygen level in graphene oxide

    NASA Astrophysics Data System (ADS)

    Celina Selvakumari, J.; Dhanalakshmi, J.; Pathinettam Padiyan, D.

    2016-10-01

    The intention of this work is to reduce the oxygen level in graphene oxide. The reduction process was initiated while preparing graphene oxide using modified Hummer’s method. In this new method, increase in hydrogen peroxide concentration during the preparation process results in the oxygen content reduction. Adding green tea (camellia sinensis) extract with increased hydrogen peroxide results in further reduction of oxygen content and changed the graphene oxide to reduced graphene oxide. The structural and optical properties of the new found reduced graphene oxide was analysed using XRD, FTIR, TEM, Raman and UV–vis spectra. The overall observation reflects that the sp3 carbon network of graphene oxide changed into sp2 carbon lattice of graphene which is very handful in supercapacitor and biosensor fields.

  11. Compatibility Studies of Hydrogen Peroxide and a New Hypergolic Fuel Blend

    NASA Technical Reports Server (NTRS)

    Baldridge, Jennifer; Villegas, Yvonne

    2002-01-01

    Several preliminary materials compatibility studies have been conducted to determine the practicality of a new hypergolic fuel system. Hypergolic fuel ignites spontaneously as the oxidizer decomposes and releases energy in the presence of the fuel. The bipropellant system tested consists of high-test hydrogen peroxide (HTP) and a liquid fuel blend consisting of a hydrocarbon fuel, an ignition enhancer and a transition metal catalyst. In order for further testing of the new fuel blend to take place, some basic materials compatibility and HTP decomposition studies must be accomplished. The thermal decomposition rate of HTP was tested using gas evolution and isothermal microcalorimetry (IMC). Materials were analyzed for compatibility with hydrogen peroxide including a study of the affect welding has on stainless steel elemental composition and its relation to HTP decomposition. Compatibility studies of valve materials in the fuel blend were performed to determine the corrosion resistance of the materials.

  12. Oxidizer Selection for the ISTAR Program (Liquid Oxygen versus Hydrogen Peroxide)

    NASA Technical Reports Server (NTRS)

    Quinn, Jason Eugene; Koelbl, Mary E. (Technical Monitor)

    2002-01-01

    This paper discusses a study of two alternate oxidizers, liquid oxygen and hydrogen peroxide, for use in a rocket based combined cycle (RBCC) demonstrator vehicle. The flight vehicle is baselined as an airlaunched self-powered Mach 0.7 to 7 demonstration of an RBCC engine through all or its air breathing propulsion modes. Selection of an alternate oxidizer has the potential to lower overall vehicle size, system complexity/ cost and ultimately the total program risk. This trade study examined the oxidizer selection effects upon the overall vehicle performance, safety and operations. After consideration of all the technical and programmatic details available at this time, 90% hydrogen peroxide was selected over liquid oxygen for use in this program.

  13. Sensitivity of tropospheric hydrogen peroxide to global chemical and climate change

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Stewart, Richard W.; Owens, Melody A.

    1989-01-01

    The sensitivities of tropospheric HO2 and hydrogen peroxide (H2O2) levels to increases in CH4, CO, and NO emissions and to changes in stratospheric O3 and tropospheric O3 and H2O have been evaluated with a one-dimensional photochemical model. Specific scenarios of CH4-CO-NO(x) emissions and global climate changes are used to predict HO2 and H2O2 changes between 1980 and 2030. Calculations are made for urban and nonurban continental conditions and for low latitudes. Generally, CO and CH4 emissions will enhance H2O2; NO emissions will suppress H2O2 except in very low NO(x) regions. A global warming or stratospheric O3 depletion will add to H2O2. Hydrogen peroxide increases from 1980 to 2030 could be 100 percent or more in the urban boundary layer.

  14. Prussian blue-modified nanoporous gold film electrode for amperometric determination of hydrogen peroxide.

    PubMed

    Ghaderi, Seyran; Mehrgardi, Masoud Ayatollahi

    2014-08-01

    In this manuscript, the electrocatalytic reduction of hydrogen peroxides on Prussian blue (PB) modified nanoporous gold film (NPGF) electrode is described. The PB/NPGF is prepared by simple anodizing of a smooth gold film followed by PB film electrodeposition method. The morphology of the PB/NPGF electrode is characterized using scanning electron microscopy (SEM). The effect of solution pH and the scan rates on the voltammetric responses of hydrogen peroxide have also been examined. The amperometric determination of H2O2 shows two linear dynamic responses over the concentration range of 1μM-10μM and 10μM-100μM with a detection limit of 3.6×10(-7)M. Furthermore, this electrode demonstrated good stability, repeatability and selectivity remarkably.

  15. Preparation of activated carbons previously treated with hydrogen peroxide: Study of their porous texture

    NASA Astrophysics Data System (ADS)

    López de Letona Sánchez, M.; Macías-García, A.; Díaz-Díez, M. A.; Cuerda-Correa, E. M.; Gañán-Gómez, J.; Nadal-Gisbert, A.

    2006-06-01

    Cedar wood was used as raw material for the preparation of activated carbons by treatment with hydrogen peroxide of different concentrations. The samples were next carbonised and activated under CO 2 atmosphere. The activated carbons were characterised by means of the adsorption isotherms of N 2 at 77 K, as well as by applying the Density Functional Theory (DFT) method and mercury porosimetry. The experimental results corresponding to the activated samples indicate a more remarkable porous development as a consequence of the treatment with hydrogen peroxide, probably due to the elimination of surface complexes produced during the activation step. The DFT diagrams point out that the activating treatment favours the development of medium and narrow-size micropores whereas the carbonisation process leads to the development of wide micropores of size close to that corresponding to mesopores.

  16. The Life Story of Hydrogen Peroxide III: Chirality and Physical Effects at the Dawn of Life.

    PubMed

    Ball, Rowena; Brindley, John

    2016-03-01

    It is a remarkable observed fact that all life on Earth is homochiral, its biology using exclusively the D-enantiomer of ribose, the sugar moiety of the ribonucleic acids, and the L-enantiomers of the chiral amino acids. Motivated by concurrent work that elaborates further the role of hydrogen peroxide in providing an oscillatory drive for the RNA world (Ball & Brindley 2015a, J. R. Soc. Interface 12, 20150366, and Ball & Brindley 2015b, this journal, in press), we reappraise the structure and physical properties of this small molecule within this context. Hydrogen peroxide is the smallest, simplest molecule to exist as a pair of non-superimposable mirror images, or enantiomers, a fact which leads us to develop the hypothesis that its enantiospecific interactions with ribonucleic acids led to enantioselective outcomes. We propose a mechanism by which these chiral interactions may have led to amplification of D-ribonucleic acids and extinction of L-ribonucleic acids.

  17. Hydrogen peroxide concentration by pervaporation of a ternary liquid solution in microfluidics.

    PubMed

    Ziemecka, Iwona; Haut, Benoît; Scheid, Benoit

    2015-01-21

    Pervaporation in a microfluidic device is performed on liquid ternary solutions of hydrogen peroxide-water-methanol in order to concentrate hydrogen peroxide (H2O2) by removing methanol. The quantitative analysis of the pervaporation of solutions with different initial compositions is performed, varying the operating temperature of the microfluidic device. Experimental results together with a mathematical model of the separation process are used to understand the effect of the operating conditions on the microfluidic device efficiency. The parameters influencing significantly the performance of pervaporation in the microfluidic device are determined and the limitations of the process are discussed. For the analysed system, the operating temperature of the chip has to be below the temperature at which H2O2 decomposes. Therefore, the choice of an adequate reduced operating pressure is required, depending on the expected separation efficiency.

  18. The Life Story of Hydrogen Peroxide III: Chirality and Physical Effects at the Dawn of Life

    NASA Astrophysics Data System (ADS)

    Ball, Rowena; Brindley, John

    2016-03-01

    It is a remarkable observed fact that all life on Earth is homochiral, its biology using exclusively the D-enantiomer of ribose, the sugar moiety of the ribonucleic acids, and the L-enantiomers of the chiral amino acids. Motivated by concurrent work that elaborates further the role of hydrogen peroxide in providing an oscillatory drive for the RNA world (Ball & Brindley 2015a, J. R. Soc. Interface 12, 20150366, and Ball & Brindley 2015b, this journal, in press), we reappraise the structure and physical properties of this small molecule within this context. Hydrogen peroxide is the smallest, simplest molecule to exist as a pair of non-superimposable mirror images, or enantiomers, a fact which leads us to develop the hypothesis that its enantiospecific interactions with ribonucleic acids led to enantioselective outcomes. We propose a mechanism by which these chiral interactions may have led to amplification of D-ribonucleic acids and extinction of L-ribonucleic acids.

  19. Radiation-induced degradation of an epoxy thermoset supported by hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Nowicki, Andrzej; Przybytniak, Grażyna; Legocka, Izabella; Mirkowski, Krzysztof

    2014-01-01

    Epoxy resin was decomposed applying two complementary treatments, namely (1) soaking up with 30% aqueous solution of hydrogen peroxide and (2) exposure of the swelled material to ionizing radiation in air atmosphere over doses up to 1000 kGy. The phase transition characteristic determined by the DSC technique revealed that both factors, swelling with oxidizing agent and irradiation applied sequentially induce in the resin deep structural changes resulting in the rise of two new exothermic transitions assigned to hydrogen peroxide decomposition and resin oxidation. The flexural stress at break measurements confirmed significant influence of H2O2 on the mechanical properties of the irradiated material which, under applied conditions, is efficiently decayed via oxidative degradation. On the basis of results obtained by EPR spectroscopy chemical mechanism of the radiation induced degradation was proposed.

  20. Is SS-A/Ro52 a hydrogen peroxide-sensitive signaling molecule?

    PubMed

    Nobuhara, Yumiko; Kawano, Seiji; Kageyama, Goichi; Sugiyama, Daisuke; Saegusa, Jun; Kumagai, Shunichi

    2007-03-01

    SS-A/Ro52 (Ro52) protein is one of the targets of autoantibodies in Sjogren's syndrome and systemic lupus erythematosus. Ro52 structurally belongs to the RING-B-box/coiled-coil family, which appears to carry out diverse functions, but the physiological function of Ro52 remains largely unknown. Here, the authors demonstrate that hydrogen peroxide but not other oxidative stressors induced translocation of Ro52 protein from the cytoplasm to the nucleus and this phenomenon was attenuated by inhibition of MAP kinases, ERK in particular. These findings raise the possibility that SS-A/Ro52 may function as a hydrogen peroxide-selective, oxidative stress-sensitive signaling molecule that is activated via the MAP kinase pathway.

  1. Lichen metabolites modulate hydrogen peroxide and nitric oxide in mouse macrophages.

    PubMed

    Carlos, Iracilda Z; Quilles, Marcela B; Carli, Camila B A; Maia, Danielle C G; Benzatti, Fernanda P; Lopes, Thiago I B; Gianini, Aline S; Brum, Rosenei L; Vilegas, Wagner; dos Santos, Lourdes C; Honda, Neli K

    2009-01-01

    The activities of perlatolic acid (1), atranorin (2), and lecanoric acid (3) and their derivatives, such as orsellinates and beta-methyl orsellinates obtained by alcoholysis, were assessed for stimulation of the release of hydrogen peroxide and nitric oxide in cultures of peritoneal macrophage cells from mice. The hydrogen peroxide production was estimated by oxidation of phenol red, while the Griess reagent was used to determine the nitric oxide production. 1 and 4-methoxy-ethyl orsellinate (XVII) were the compounds that induced the greatest release of H2O2, whereas n-pentyl orsellinate (IV), iso-propyl orsellinate (V), sec-butyl orsellinate (VI), and XVII induced a small release of NO. These results indicate that lichen products and their derivatives have potential immune-modulating activities. PMID:19957434

  2. C3-symmetric Ti(IV) triphenolate amino complexes as sulfoxidation catalysts with aqueous hydrogen peroxide.

    PubMed

    Mba, Myriam; Prins, Leonard J; Licini, Giulia

    2007-01-01

    [reaction: see text] The Ti(IV) complex 2c bearing a C3-symmetric triphenolate amine ligand is an air and moisture tolerant complex that efficiently catalyzes sulfoxidation reactions at room temperature without previous activation (catalyst loading down to 0.01%, TONs up to 8000, TOFs up to 1700 h-1, quantitative yields). Reactions were performed with aqueous hydrogen peroxide as oxidant, which adds value to the methodology from the environmental viewpoint.

  3. Hydrogen peroxide sensing at MnO2/carbonized nanostructured polyaniline electrode

    NASA Astrophysics Data System (ADS)

    Šljukić, B.; Stojković, I.; Cvijetićanin, N.; Ćirić-Marjanović, G.

    2011-12-01

    Manganese dioxide modified carbonized nanostructured polyaniline (MnO2/Carb-nanoPANI) was prepared via a novel hydrothermal procedure. The synthesized material was characterized using XRD, SEM and TG-DTA analysis. Furthermore, MnO2/Carb-nanoPANI was examined as electrode material for potential application in the field of electroanalysis. It showed a high electrocatalytic activity for the sensing of hydrogen peroxide in an aqueous media.

  4. Chlorine monoxide radical, ozone, and hydrogen peroxide: stratospheric measurements by microwave limb sounding

    SciTech Connect

    Waters, J.W.; Hardy, J.C.; Jarnot, R.F.; Pickett, H.M.

    1981-10-02

    Profiles of stratospheric ozone and chlorine monoxide radical (ClO) were obtained from balloon measurements of atmospheric limb thermal emission at millimeter wavelengths. The ClO measurements, important for assessing the predicted depletion of stratospheric ozone by chlorine from industrial sources, are in close agreement with present theory. The predicted decrease of ClO at sunset was measured. A tentative value for the stratospheric abundance of hydrogen peroxide was also determined.

  5. Improved sensing response of photo activated ZnO thin film for hydrogen peroxide detection.

    PubMed

    Parthasarathy, S; Nandhini, V; Jeyaprakash, B G

    2016-11-15

    The nanostructured ZnO thin films were deposited using spray pyrolysis technique. Formation of polycrystalinity with hexagonal wurtzite structure was observed from the structural study. Highly dense spherical shaped nanoparticles with fine crystallites were observed from the surface morphological studies. The light induced hydrogen peroxide vapour sensing was done using chemi-resistive method and its effect on the sensing response was studied and reported.

  6. Low-temperature decontamination with hydrogen peroxide or chlorine dioxide for space applications.

    PubMed

    Pottage, T; Macken, S; Giri, K; Walker, J T; Bennett, A M

    2012-06-01

    The currently used microbial decontamination method for spacecraft and components uses dry-heat microbial reduction at temperatures of >110°C for extended periods to prevent the contamination of extraplanetary destinations. This process is effective and reproducible, but it is also long and costly and precludes the use of heat-labile materials. The need for an alternative to dry-heat microbial reduction has been identified by space agencies. Investigations assessing the biological efficacy of two gaseous decontamination technologies, vapor hydrogen peroxide (Steris) and chlorine dioxide (ClorDiSys), were undertaken in a 20-m(3) exposure chamber. Five spore-forming Bacillus spp. were exposed on stainless steel coupons to vaporized hydrogen peroxide and chlorine dioxide gas. Exposure for 20 min to vapor hydrogen peroxide resulted in 6- and 5-log reductions in the recovery of Bacillus atrophaeus and Geobacillus stearothermophilus, respectively. However, in comparison, chlorine dioxide required an exposure period of 60 min to reduce both B. atrophaeus and G. stearothermophilus by 5 logs. Of the three other Bacillus spp. tested, Bacillus thuringiensis proved the most resistant to hydrogen peroxide and chlorine dioxide with D values of 175.4 s and 6.6 h, respectively. Both low-temperature decontamination technologies proved effective at reducing the Bacillus spp. tested within the exposure ranges by over 5 logs, with the exception of B. thuringiensis, which was more resistant to both technologies. These results indicate that a review of the indicator organism choice and loading could provide a more appropriate and realistic challenge for the sterilization procedures used in the space industry. PMID:22492450

  7. Oxidation of chlorophenols catalyzed by Coprinus cinereus peroxidase with in situ production of hydrogen peroxide.

    PubMed

    Pezzotti, Fabio; Okrasa, Krzysztof; Therisod, Michel

    2004-01-01

    Degradation of 2,6-dichlorophenol (2,6-DCP) was accomplished by oxidation catalyzed by Coprinus cinereus peroxidase. Immobilization of the enzyme in a polyacrylamide matrix enhanced DCP oxidation. Hydrogen peroxide, peroxidase's natural substrate, was produced enzymatically in situ to avoid peroxidase inactivation by its too high concentration. In the case of larger scale utilization, the method would also avoid direct handling of this hazardous reagent.

  8. Efficacy of formalin and hydrogen peroxide to increase survival of channel catfish infected with saprolegniasis

    USGS Publications Warehouse

    Rach, J.J.; Schreier, T.; Gaikowski, M.P.; Schleis, S.M.

    2005-01-01

    The efficacy of formalin and hydrogen peroxide to increase survival associated with external saprolegniasis on fingerlings of channel catfish Ictalurus punctatus was evaluated in four laboratory trials. Fungal epizootics were initiated according to procedures developed in a fungal-disease model. Fish were abraded with a dremel tool and then placed in an aerated static infection tank containing fungal-infected hemp seeds held in teaballs that were suspended in 100 L of water for 24 h (trials 1-3) or 6 h (trial 4). In the formalin trials, treatment regimens of 0, 82, and 166 mg/L (trial 1) or 0 and 83 mg/L (trial 2) were administered to channel catfish for 60 min once every other day for a total of three treatments (trial 1) or once daily for a total of seven treatments (trial 2). In the hydrogen peroxide trials, treatment regimens of 0, 75, and 102 mg/L (trial 3) or 0 and 75 mg/L (trial 4) were administered to channel catfish for 60 min once every other day for a total of three treatments. Each treatment regimen was tested in triplicate, with 10 fish per replicate. Formalin exposures of 83 (seven treatments; 33% survival) and 166 mg/L (three treatments; 63% survival) for 60 min significantly (P <= 0.01) increased channel catfish survival in comparison with controls (of which 3% and 13%, respectively, survived). In trial 4, hydrogen peroxide exposure of 75 mg/L (63% survival) for 60 min significantly (P <= 0.01) increased channel catfish survival in comparison with the untreated controls (13% survival). Formalin and hydrogen peroxide treatments were effective in increasing survival in channel catfish infected with fungus.

  9. Cobalt phosphide nanowires: an efficient electrocatalyst for enzymeless hydrogen peroxide detection

    NASA Astrophysics Data System (ADS)

    Liu, Danni; Chen, Tao; Zhu, Wenxin; Cui, Liang; Asiri, Abdullah M.; Lu, Qun; Sun, Xuping

    2016-08-01

    In this letter, we demonstrate for the first time that cobalt phosphide nanowires (CoP NWs) exhibit remarkable catalytic activity toward electrochemical detection of hydrogen peroxide (H2O2). As an enzymeless H2O2 sensor, such CoP NWs show a fast amperometric response within 5 s and a low detection limit of 0.48 μM. In addition, this nonenzymatic sensor displays good selectivity, long-term stability and excellent reproducibility.

  10. Using Isothermal Microcalorimetry to Determine Compatibility of Structural Materials with High Test Hydrogen Peroxide (HTP) Propellant

    NASA Technical Reports Server (NTRS)

    Gostowski, Rudy; Villegas, Yvonne; Nwosisi, Genne

    2003-01-01

    High-Test Hydrogen Peroxide (HTP) propellant (greater than or equal to 70%) offers many advantages in space launch applications; however, materials used in construction of propulsion systems must be shown to be compatible with HTP. Isothermal Microcalorimetry (IMC) was used to determine the compatibility of several metallic and non-metallic materials with 90% HTP. The results of these experiments agreed with those from immersion bath tests when the values were converted to %Active Oxygen Loss per week (%AOL/wk).

  11. Chlorine monoxide radical, ozone, and hydrogen peroxide - Stratospheric measurements by microwave limb sounding

    NASA Technical Reports Server (NTRS)

    Waters, J. W.; Hardy, J. C.; Jarnot, R. F.; Pickett, H. M.

    1981-01-01

    Profiles of stratospheric ozone and chlorine monoxide radical (ClO) have been obtained from balloon measurements of atmospheric limb thermal emission at millimeter wavelengths. The ClO measurements, important for assessing the predicted depletion of stratospheric ozone by chlorine from industrial sources, are in close agreement with present theory. The predicted decrease of ClO at sunset was measured. A tentative value for the stratospheric abundance of hydrogen peroxide was also determined.

  12. Improved sensing response of photo activated ZnO thin film for hydrogen peroxide detection.

    PubMed

    Parthasarathy, S; Nandhini, V; Jeyaprakash, B G

    2016-11-15

    The nanostructured ZnO thin films were deposited using spray pyrolysis technique. Formation of polycrystalinity with hexagonal wurtzite structure was observed from the structural study. Highly dense spherical shaped nanoparticles with fine crystallites were observed from the surface morphological studies. The light induced hydrogen peroxide vapour sensing was done using chemi-resistive method and its effect on the sensing response was studied and reported. PMID:27491004

  13. The reaction of hydrogen peroxide with nitrogen dioxide and nitric oxide.

    NASA Technical Reports Server (NTRS)

    Gray, D.; Lissi, E.; Heicklen, J.

    1972-01-01

    The reactions were studied with the aid of a mass spectrometer. A pinhole bleed system provided continuous sampling of the gas mixture in the cell during the reaction. It was found that the homogeneous reactions of nitric oxide and nitrogen dioxide with hydrogen peroxide are too slow to be of any significance in the upper atmosphere. However, the heterogeneous reactions may be important in the conversion of nitric oxide to nitrogen dioxide in the case of polluted urban atmospheres.

  14. Presence of Hydrogen Peroxide, a Source of Hydroxyl Radicals, in Acid Electrolyzed Water

    PubMed Central

    Mokudai, Takayuki; Nakamura, Keisuke; Kanno, Taro; Niwano, Yoshimi

    2012-01-01

    Background Acid electrolyzed water (AEW), which is produced through the electrolysis of dilute sodium chloride (NaCl) or potassium chloride solution, is used as a disinfectant in various fields because of its potent antimicrobial activity. The hydroxyl radical, an oxygen radical species, is often suggested as a putative active ingredient for AEW antimicrobial activity. Methodology/Principal Findings The aim of the present study is to detect hydroxyl radicals in AEW. The hydroxyl radicals in AEW prepared under different conditions were determined using an electron spin resonance (ESR) technique. A signal from 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-OH, an adduct of DMPO and the hydroxyl radical, was detected in AEW prepared by double or triple electrolyses of 1% NaCl but not of 0.1% NaCl solution. Then the presence of hydrogen peroxide as a proposed source of hydroxyl radicals was examined using a combination of ESR and a Fenton reaction. The DMPO-OH signal was clearly detected, even in AEW prepared by single electrolysis of 0.1% NaCl solution, when ferrous sulfate was added to induce a Fenton reaction, indicating the presence of hydrogen peroxide in the AEW. Since sodium formate, a hydroxyl radical scavenger, did not affect the bactericidal activity of AEW, it is concluded that the radical is unlikely to contribute to the antimicrobial activity of AEW, although a small amount of the radical is produced from hydrogen peroxide. Dimethyl sulfoxide, the other hydroxyl radical scavenger used in the present study, canceled the bactericidal activity of AEW, accompanied by complete depletion of free available chlorine, suggesting that hypochlorous acid is probably a major contributor to the antimicrobial activity. Conclusions It is strongly suggested that although hydrogen peroxide is present in AEW as a source of hydroxyl radicals, the antimicrobial activity of AEW does not depend on these radicals. PMID:23029505

  15. Low-Temperature Decontamination with Hydrogen Peroxide or Chlorine Dioxide for Space Applications

    PubMed Central

    Macken, S.; Giri, K.; Walker, J. T.; Bennett, A. M.

    2012-01-01

    The currently used microbial decontamination method for spacecraft and components uses dry-heat microbial reduction at temperatures of >110°C for extended periods to prevent the contamination of extraplanetary destinations. This process is effective and reproducible, but it is also long and costly and precludes the use of heat-labile materials. The need for an alternative to dry-heat microbial reduction has been identified by space agencies. Investigations assessing the biological efficacy of two gaseous decontamination technologies, vapor hydrogen peroxide (Steris) and chlorine dioxide (ClorDiSys), were undertaken in a 20-m3 exposure chamber. Five spore-forming Bacillus spp. were exposed on stainless steel coupons to vaporized hydrogen peroxide and chlorine dioxide gas. Exposure for 20 min to vapor hydrogen peroxide resulted in 6- and 5-log reductions in the recovery of Bacillus atrophaeus and Geobacillus stearothermophilus, respectively. However, in comparison, chlorine dioxide required an exposure period of 60 min to reduce both B. atrophaeus and G. stearothermophilus by 5 logs. Of the three other Bacillus spp. tested, Bacillus thuringiensis proved the most resistant to hydrogen peroxide and chlorine dioxide with D values of 175.4 s and 6.6 h, respectively. Both low-temperature decontamination technologies proved effective at reducing the Bacillus spp. tested within the exposure ranges by over 5 logs, with the exception of B. thuringiensis, which was more resistant to both technologies. These results indicate that a review of the indicator organism choice and loading could provide a more appropriate and realistic challenge for the sterilization procedures used in the space industry. PMID:22492450

  16. Formation of hydrogen peroxide in the silver reductor: A micro-analytical method for iron

    USGS Publications Warehouse

    Fryling, C.F.; Tooley, F.V.

    1936-01-01

    1. An attempt to determine small quantities of iron by reduction with silver followed by titration with eerie sulfate revealed an error attributable to the formation of hydrogen peroxide in the reductor. 2. By conducting the reduction in an atmosphere of hydrogen, thereby decreasing the reductor correction, and applying a correction for the indicator, it was possible to determine quantities of iron of the order of 1.5 mg. with a high degree of accuracy. 3. The method was found to be relatively rapid and not to require the use of large platinum dishes, thus possessing advantages of practical value.

  17. Suitability of different construction materials for use in aseptic processing environments decontaminated with gaseous hydrogen peroxide.

    PubMed

    Unger, Beatriz; Rauschnabel, Uta; Düthorn, Berthold; Kottke, Volker; Hertel, Christian; Rauschnabel, Johannes

    2007-01-01

    The purpose of this study is to examine the behavior of different materials towards the microbial inactivation kinetic of gaseous hydrogen peroxide. Samples of 49 materials potentially used in aseptic processing environments were inoculated with 106 spores of Geobacillus stearothermophilus ATCC #12980 and exposed to defined periods using a reproducible hydrogen peroxide bio-decontamination cycle. The inactivation characteristic of each material was investigated by means of repeated D-value calculations. The results demonstrate that different materials show highly variable performance regarding the inactivation pattern of spores on each particular surface. Not only the chemical composition of the material but also differences in manufacturing processes and surface treatments were found to have an effect on the resistance of the test organisms. From the data obtained it is concluded that some correlation exists between the calculated D-values and roughness as well as wettability of the materials. Best- and worst-case materials were identified, and the dependence of specific decontamination characteristics on material properties was investigated. It is suggested to integrate studies regarding the inactivation characteristics of incorporated materials into the construction process of new aseptic processing systems bio-decontaminated with hydrogen peroxide. PMID:17933208

  18. Sonochemical and hydrodynamic cavitation reactors for laccase/hydrogen peroxide cotton bleaching.

    PubMed

    Gonçalves, Idalina; Martins, Madalena; Loureiro, Ana; Gomes, Andreia; Cavaco-Paulo, Artur; Silva, Carla

    2014-03-01

    The main goal of this work is to develop a novel and environmental-friendly technology for cotton bleaching with reduced processing costs. This work exploits a combined laccase-hydrogen peroxide process assisted by ultrasound. For this purpose, specific reactors were studied, namely ultrasonic power generator type K8 (850 kHz) and ultrasonic bath equipment Ultrasonic cleaner USC600TH (45 kHz). The optimal operating conditions for bleaching were chosen considering the highest levels of hydroxyl radical production and the lowest energy input. The capacity to produce hydroxyl radicals by hydrodynamic cavitation was also assessed in two homogenizers, EmulsiFlex®-C3 and APV-2000. Laccase nanoemulsions were produced by high pressure homogenization using BSA (bovine serum albumin) as emulsifier. The bleaching efficiency of these formulations was tested and the results showed higher whiteness values when compared to free laccase. The combination of laccase-hydrogen peroxide process with ultrasound energy produced higher whiteness levels than those obtained by conventional methods. The amount of hydrogen peroxide was reduced 50% as well as the energy consumption in terms of temperature (reduction of 40 °C) and operating time (reduction of 90 min).

  19. Response of plant-colonizing pseudomonads to hydrogen peroxide. [Pseudomonas putida

    SciTech Connect

    Katsuwon, J.; Anderson, A.J. )

    1989-11-01

    Colonization of plant root surfaces by Pseudomonas putida may require mechanisms that protect this bacterium against superoxide anion and hydrogen peroxide produced by the root. Catalase and superoxide dismutase may be important in this bacterial defense system. Stationary-phase cells of P. putida were not killed by hydrogen peroxide (H{sub 2}O{sub 2}) at concentrations up to 10 mM, and extracts from these cells possessed three isozymic bands (A, B, and C) of catalase activity in native polyacrylamide gel electrophoresis. Logarithmic-phase cells exposed directly to hydrogen peroxide concentrations above 1 mM were killed. Extracts of logarithmic-phase cells displayed only band A catalase activity. Protection against 5 mM H{sub 2}O{sub 2} was apparent after previous exposure of the logarithmic-phase cells to nonlethal concentrations (30 to 300 {mu}M) of H{sub 2}O{sub 2}. Extracts of these protected cells possessed enhanced catalase activity of band A and small amounts of bands B and C. A single form of superoxide dismutase and isoforms of catalase were apparent in extracts from a foliar intercellular pathogen, Pseudomonas syringae pv. phaseolicola. The mobilities of these P. syringae enzymes were distinct from those of enzymes in P. putida extracts.

  20. Fabrication of ethanol blended hydrogen peroxide 50 mN class MEMS thruster

    NASA Astrophysics Data System (ADS)

    Huh, Jeongmoo; Lee, Jeongsub; Seo, Daeban; Kang, Shinjae; Kwon, Sejin

    2013-12-01

    MEMS thruster with blended propellant was fabricated and experimentally tested in order to improve specific impulse of micro scale monopropellant thruster and to improve stability of thrust to be better. 90 wt. % H2O2 blended with 25 O/F ratio ethanol was used as propellant of thruster and platinum on alumina support was used as catalyst for decomposition of propellant. Thruster was made by five layers of photosensitive glasses. Four layers were integrated by thermal bonding method and catalyst was directly inserted into chamber before UV bonding process for the last layer bonding. Results of experimental tests showed ethanol blended hydrogen peroxide had higher specific impulse than unblended hydrogen peroxide. Expected improvement of thrust stability due to the blended propellant was found only in the transient state of thrust. Also, unlike the thrust instability of vertical type thruster of previous research, improvement of thrust stability was found owe to horizontal type thruster pattern on glass, despite aspect ratio limitation of glass fabrication with wet etching process. During the experimental test, combustion phenomena of ethanol with decomposed hydrogen peroxide were observed through glass layer and it made fracture on structure of thruster.

  1. Toxicity of abiotic stressors to Fusarium species: differences in hydrogen peroxide and fungicide tolerance.

    PubMed

    Nagygyörgy, Emese D; Kovács, Barbara; Leiter, Eva; Miskei, Márton; Pócsi, István; Hornok, László; Adám, Attila L

    2014-06-01

    Stress sensitivity of three related phytopathogenic Fusarium species (Fusarium graminearum, Fusarium oxysporum and Fusarium verticillioides) to different oxidative, osmotic, cell wall, membrane, fungicide stressors and an antifungal protein (PAF) were studied in vitro. The most prominent and significant differences were found in oxidative stress tolerance: all the three F. graminearum strains showed much higher sensitivity to hydrogen peroxide and, to a lesser extent, to menadione than the other two species. High sensitivity of F. verticillioides strains was also detectable to an azole drug, Ketoconazole. Surprisingly, no or limited differences were observed in response to other oxidative, osmotic and cell wall stressors. These results indicate that fungal oxidative stress response and especially the response to hydrogen peroxide (this compound is involved in a wide range of plant-fungus interactions) might be modified on niche-specific manner in these phylogenetically related Fusarium species depending on their pathogenic strategy. Supporting the increased hydrogen peroxide sensitivity of F. graminearum, genome-wide analysis of stress signal transduction pathways revealed the absence one CatC-type catalase gene in F. graminearum in comparison to the other two species.

  2. Singlet molecular oxygen production in the reaction of peroxynitrite with hydrogen peroxide.

    PubMed

    Di Mascio, P; Bechara, E J; Medeiros, M H; Briviba, K; Sies, H

    1994-12-01

    Peroxynitrite and hydrogen peroxide are mediators of cytotoxicity. This study shows that the peroxynitrite anion reacts with hydrogen peroxide to release oxygen accompanied by emission of chemiluminescence (CL). Direct characterization of this light emission attributes it to the transition of singlet molecular oxygen to the triplet ground state. Chemiluminescence was monitored: (i) by dimol light emission in the red spectral region (> 610 nm) using a red-sensitive photomultiplier; and (ii) by monomol light emission in the infrared (1270 nm) with a liquid nitrogen-cooled germanium diode. These properties of photoemission and the enhancing effect of deuterium oxide on CL intensity as well as the quenching effect of sodium azide are diagnostic of molecular oxygen in the excited singlet state. For comparison, singlet molecular oxygen arising from the thermolysis of the water-soluble endoperoxide of 3,3'-(1,4-naphthylidene)dipropionate or from the hypochlorite/H2O2 system was also monitored. These novel observations identify a potential singlet oxygen-dependent mechanism contributing to cytotoxicity mediated by peroxynitrite and hydrogen peroxide.

  3. Hydrogen peroxide treatment results in reduced curvature values in the Arabidopsis root apex.

    PubMed

    Noriega, Arturo; Tocino, Angel; Cervantes, Emilio

    2009-03-15

    Curvature of a plane curve is a measurement related to its shape. A Mathematica code was developed [Cervantes E, Tocino A. J Plant Physiol 2005;162:1038-1045] to obtain parametric equations from microscopic images of the Arabidopsis thaliana root apex. In addition, curvature values for these curves were given. It was shown that ethylene-insensitive mutants (etr1-1 and ein2-1) have reduced curvature values in the root apex. It has also been shown that blocking ethylene action by norbornadiene, an ethylene inhibitor, results in reduced curvature values in the two outer cell layers of the root apex [Noriega A, Cervantes E, Tocino A. J Plant Physiol 2008, in press]. Because ethylene action has been related with hydrogen peroxide [Desikan R, Hancock JT, Bright J, Harrison J, Weir I, Hooley R, Neill SJ. Plant Physiol 2005;137:831-834], the effect of a treatment with hydrogen peroxide in the curvature values of three successive layers of the root apex in Arabidopsis thaliana was investigated by confocal microscopy. Treatment with 10mM hydrogen peroxide resulted in reduced curvature values in the three layers. The effect was associated with smaller cells having higher circularity indices. The results are discussed in the context of the role of ethylene in development.

  4. Hydrogen peroxide-dependent uptake of iodine by marine Flavobacteriaceae bacterium strain C-21.

    PubMed

    Amachi, Seigo; Kimura, Koh; Muramatsu, Yasuyuki; Shinoyama, Hirofumi; Fujii, Takaaki

    2007-12-01

    The cells of the marine bacterium strain C-21, which is phylogenetically closely related to Arenibacter troitsensis, accumulate iodine in the presence of glucose and iodide (I-). In this study, the detailed mechanism of iodine uptake by C-21 was determined using a radioactive iodide tracer, 125I-. In addition to glucose, oxygen and calcium ions were also required for the uptake of iodine. The uptake was not inhibited or was only partially inhibited by various metabolic inhibitors, whereas reducing agents and catalase strongly inhibited the uptake. When exogenous glucose oxidase was added to the cell suspension, enhanced uptake of iodine was observed. The uptake occurred even in the absence of glucose and oxygen if hydrogen peroxide was added to the cell suspension. Significant activity of glucose oxidase was found in the crude extracts of C-21, and it was located mainly in the membrane fraction. These findings indicate that hydrogen peroxide produced by glucose oxidase plays a key role in the uptake of iodine. Furthermore, enzymatic oxidation of iodide strongly stimulated iodine uptake in the absence of glucose. Based on these results, the mechanism was considered to consist of oxidation of iodide to hypoiodous acid by hydrogen peroxide, followed by passive translocation of this uncharged iodine species across the cell membrane. Interestingly, such a mechanism of iodine uptake is similar to that observed in iodine-accumulating marine algae.

  5. Sonochemical and hydrodynamic cavitation reactors for laccase/hydrogen peroxide cotton bleaching.

    PubMed

    Gonçalves, Idalina; Martins, Madalena; Loureiro, Ana; Gomes, Andreia; Cavaco-Paulo, Artur; Silva, Carla

    2014-03-01

    The main goal of this work is to develop a novel and environmental-friendly technology for cotton bleaching with reduced processing costs. This work exploits a combined laccase-hydrogen peroxide process assisted by ultrasound. For this purpose, specific reactors were studied, namely ultrasonic power generator type K8 (850 kHz) and ultrasonic bath equipment Ultrasonic cleaner USC600TH (45 kHz). The optimal operating conditions for bleaching were chosen considering the highest levels of hydroxyl radical production and the lowest energy input. The capacity to produce hydroxyl radicals by hydrodynamic cavitation was also assessed in two homogenizers, EmulsiFlex®-C3 and APV-2000. Laccase nanoemulsions were produced by high pressure homogenization using BSA (bovine serum albumin) as emulsifier. The bleaching efficiency of these formulations was tested and the results showed higher whiteness values when compared to free laccase. The combination of laccase-hydrogen peroxide process with ultrasound energy produced higher whiteness levels than those obtained by conventional methods. The amount of hydrogen peroxide was reduced 50% as well as the energy consumption in terms of temperature (reduction of 40 °C) and operating time (reduction of 90 min). PMID:24035719

  6. A spectrometric method for hydrogen peroxide concentration measurement with a reusable and cost-efficient sensor.

    PubMed

    Hsu, Cheng-Chih; Lo, Yuan-Rong; Lin, Yu-Chian; Shi, Yi-Cen; Li, Pang-Lung

    2015-01-01

    In this study we developed a low cost sensor for measuring the concentration of hydrogen peroxide (H₂O₂) in liquids utilizing a spectrometric method. The sensor was tested using various concentrations of a peroxidase enzyme immobilized on a glass substrate. H₂O₂ can be catalyzed by peroxidase and converted into water and oxygen. The reagent 4-amino-phenazone takes up oxygen together with phenol to form a colored product that has absorption peaks at 510 nm and 450 nm. The transmission intensity is strongly related to the hydrogen peroxide concentration, so can be used for quantitative analysis. The measurement range for hydrogen peroxide is from 5 × 10(-)⁵% to 1 × 10(-3)% (0.5 ppm to 10 ppm) and the results show high linearity. This device can achieve a sensitivity and resolution of 41,400 (photon count/%) and 3.49 × 10(-5)% (0.35 ppm), respectively. The response time of the sensor is less than 3 min and the sensor can be reused for 10 applications with similar performance. PMID:26473862

  7. A spectrometric method for hydrogen peroxide concentration measurement with a reusable and cost-efficient sensor.

    PubMed

    Hsu, Cheng-Chih; Lo, Yuan-Rong; Lin, Yu-Chian; Shi, Yi-Cen; Li, Pang-Lung

    2015-10-12

    In this study we developed a low cost sensor for measuring the concentration of hydrogen peroxide (H₂O₂) in liquids utilizing a spectrometric method. The sensor was tested using various concentrations of a peroxidase enzyme immobilized on a glass substrate. H₂O₂ can be catalyzed by peroxidase and converted into water and oxygen. The reagent 4-amino-phenazone takes up oxygen together with phenol to form a colored product that has absorption peaks at 510 nm and 450 nm. The transmission intensity is strongly related to the hydrogen peroxide concentration, so can be used for quantitative analysis. The measurement range for hydrogen peroxide is from 5 × 10(-)⁵% to 1 × 10(-3)% (0.5 ppm to 10 ppm) and the results show high linearity. This device can achieve a sensitivity and resolution of 41,400 (photon count/%) and 3.49 × 10(-5)% (0.35 ppm), respectively. The response time of the sensor is less than 3 min and the sensor can be reused for 10 applications with similar performance.

  8. Numerical and experimental analysis of heat transfer in injector plate of hydrogen peroxide hybrid rocket motor

    NASA Astrophysics Data System (ADS)

    Cai, Guobiao; Li, Chengen; Tian, Hui

    2016-11-01

    This paper is aimed to analyze heat transfer in injector plate of hydrogen peroxide hybrid rocket motor by two-dimensional axisymmetric numerical simulations and full-scale firing tests. Long-time working, which is an advantage of hybrid rocket motor over conventional solid rocket motor, puts forward new challenges for thermal protection. Thermal environments of full-scale hybrid rocket motors designed for long-time firing tests are studied through steady-state coupled numerical simulations of flow field and heat transfer in chamber head. The motor adopts 98% hydrogen peroxide (98HP) oxidizer and hydroxyl-terminated poly-butadiene (HTPB) based fuel as the propellants. Simulation results reveal that flowing liquid 98HP in head oxidizer chamber could cool the injector plate of the motor. The cooling of 98HP is similar to the regenerative cooling in liquid rocket engines. However, the temperature of the 98HP in periphery portion of the head oxidizer chamber is higher than its boiling point. In order to prevent the liquid 98HP from unexpected decomposition, a thermal protection method for chamber head utilizing silica-phenolics annular insulating board is proposed. The simulation results show that the annular insulating board could effectively decrease the temperature of the 98HP in head oxidizer chamber. Besides, the thermal protection method for long-time working hydrogen peroxide hybrid rocket motor is verified through full-scale firing tests. The ablation of the insulating board in oxygen-rich environment is also analyzed.

  9. High loading Pt nanoparticles on functionalization of carbon nanotubes for fabricating nonenzyme hydrogen peroxide sensor.

    PubMed

    Li, Xiaoyan; Liu, Xiuhui; Wang, Weiwei; Li, Lin; Lu, Xiaoquan

    2014-09-15

    A very efficient, simple approach was developed to fabricate a high Pt nanoparticles-loading multiwall carbon nanotube (MWCNTs) amperometric sensor for hydrogen peroxide (H2O2) determination. In this strategy, MWCNTs were first functionalized with an anionic surfactant, sodium dodecyl sulfate (SDS); then the Pt nanoparticles (NPs) were loaded on MWCNTs-SDS by electrodepositing. The large amounts of Pt nanoparticles could be well deposited on the surface of the MWCNTs-SDS modified electrode, as revealed by scanning electron microscopy (SEM). In addition, the PtNPs/MWCNTs-SDS composite was also characterized by electrochemical methods including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experimental results demonstrated that the constructed electrode exhibited good catalytic activity toward the hydrogen peroxide, and obtained a wide linear range from 5.8×10(-9) to 1.1×10(-3) M with a limit of detection (LOD) of 1.9×10(-9) M, which was superior to that obtained with other H2O2 electrochemical sensors reported previously. Moreover, it can also be applied to real samples analysis. The excellent performance of hydrogen peroxide sensor was ascribed to the MWCNTs-SDS composites being used as effective load matrix for the deposition of PtNPs and the synergistic amplification effect of the two kinds of nanomaterials-PtNPs and MWCNTs.

  10. Erythrocyte membrane stability to hydrogen peroxide is decreased in Alzheimer disease.

    PubMed

    Gilca, Marilena; Lixandru, Daniela; Gaman, Laura; Vîrgolici, Bogdana; Atanasiu, Valeriu; Stoian, Irina

    2014-01-01

    The brain and erythrocytes have similar susceptibility toward free radicals. Therefore, erythrocyte abnormalities might indicate the progression of the oxidative damage in Alzheimer disease (AD). The aim of this study was to investigate erythrocyte membrane stability and plasma antioxidant status in AD. Fasting blood samples (from 17 patients with AD and 14 healthy controls) were obtained and erythrocyte membrane stability against hydrogen peroxide and 2,2'-azobis-(2-amidinopropane) dihydrochloride (AAPH), serum Trolox equivalent antioxidant capacity (TEAC), residual antioxidant activity or gap (GAP), erythrocyte catalase activity (CAT), erythrocyte superoxide dismutase (SOD) activity, erythrocyte nonproteic thiols, and total plasma thiols were determined. A significant decrease in erythrocyte membrane stability to hydrogen peroxide was found in AD patients when compared with controls (P<0.05). On the contrary, CAT activity (P<0.0001) and total plasma thiols (P<0.05) were increased in patients with AD compared with controls. Our results indicate that the most satisfactory measurement of the oxidative stress level in the blood of patients with AD is the erythrocyte membrane stability to hydrogen peroxide. Reduced erythrocyte membrane stability may be further evaluated as a potential peripheral marker for oxidative damage in AD.

  11. Functional activation of the egr-1 (early growth response-1) gene by hydrogen peroxide.

    PubMed

    Nose, K; Ohba, M

    1996-06-01

    The redox-based regulation of gene expression is one of the fundamental mechanisms of cellular functions, and hydrogen peroxide seems to act as an intracellular second messenger of signal transduction of cytokines. Hydrogen peroxide at non-toxic doses induced the accumulation of mRNA for the early growth response-1 (egr-1) gene in mouse osteoblastic cells. The Egr-1 protein is a transcription factor that binds the GCGGGGGCG sequence and contains a zinc-finger structure that is essential for DNA binding. Egr-1 protein is sensitive to oxidative stress and loses specific DNA-binding activity when exposed to high levels of oxidative stress. Incubating cells with hydrogen peroxide at about 50 microM, however, increased the accumulation of Egr-1 protein, and the Egr-1 product seemed to be functional, judging by its binding activity to the GCGGGGGCG sequence and its ability to activate the chloramphenicol acetyltransferase reporter gene under the control of the human thymidine kinase enhancer containing the Egr-1 binding sequence. It was reported that the activity of Egr-1 protein as a transcription factor was negatively regulated by active oxygens. However, with appropriate concentrations of active oxygen, its capacity to bind a specific DNA sequence and to enhance the transcriptional activity of target genes is thought to be elevated.

  12. Effectiveness of ultraviolet devices and hydrogen peroxide systems for terminal room decontamination: Focus on clinical trials.

    PubMed

    Weber, David J; Rutala, William A; Anderson, Deverick J; Chen, Luke F; Sickbert-Bennett, Emily E; Boyce, John M

    2016-05-01

    Over the last decade, substantial scientific evidence has accumulated that indicates contamination of environmental surfaces in hospital rooms plays an important role in the transmission of key health care-associated pathogens (eg, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, Acinetobacter spp). For example, a patient admitted to a room previously occupied by a patient colonized or infected with one of these pathogens has a higher risk for acquiring one of these pathogens than a patient admitted to a room whose previous occupant was not colonized or infected. This risk is not surprising because multiple studies have demonstrated that surfaces in hospital rooms are poorly cleaned during terminal cleaning. To reduce surface contamination after terminal cleaning, no touch methods of room disinfection have been developed. This article will review the no touch methods, ultraviolet light devices, and hydrogen peroxide systems, with a focus on clinical trials which have used patient colonization or infection as an outcome. Multiple studies have demonstrated that ultraviolet light devices and hydrogen peroxide systems have been shown to inactivate microbes experimentally plated on carrier materials and placed in hospital rooms and to decontaminate surfaces in hospital rooms naturally contaminated with multidrug-resistant pathogens. A growing number of clinical studies have demonstrated that ultraviolet devices and hydrogen peroxide systems when used for terminal disinfection can reduce colonization or health care-associated infections in patients admitted to these hospital rooms. PMID:27131140

  13. The motivational benefits of a dentifrice containing baking soda and hydrogen peroxide.

    PubMed

    Fischman, S L; Kugel, G; Truelove, R B; Nelson, B J; Cancro, L P

    1992-01-01

    Twenty-two family practice dentists, in a large metropolitan area, were recruited to act as independent examiners in a study to evaluate the compliance of their patients to accept a good oral hygiene regimen with the use of a fluoride dentifrice, containing hydrogen peroxide and baking soda, dispensed from a dual dispensing package. To evaluate compliance, the dentists attended an orientation seminar and were trained to assess gingival health using the CPITN periodontal probe. Each dentist evaluated the gingival health status of five to seven of his own patients, initially and after one and three months of product use following hygiene instruction and product assignment. One-hundred and thirty-one patients successfully completed the study. After one month of using the hydrogen peroxide/baking soda toothpaste, the mean reduction in bleeding sites was 53%; at three months the reduction was 62%. The hydrogen peroxide/baking soda dentifrice was well accepted by dentist and patient, and a discernible improvement in oral health of the patients was achieved when the product was used in a conscientious oral hygiene program.

  14. Determination of hydrogen peroxide concentrations by flow injection analysis based on the enhanced chemiluminescent reaction using peroxidase

    SciTech Connect

    Eremin, S.A.; Vlasenko, S.B.; Osipov, A.P.; Eremina, I.D.; Egerov, A.M. )

    1989-01-01

    The technique of flow injection analysis was employed in the determination of hydrogen peroxide. The method was based on the chemiluminescence reaction of luminol with H{sub 2}O{sub 2} which is catalyzed by horseradish peroxidase and enhanced by p-iodophenol. Hydrogen peroxide was linearly detected in the range 10{sup {minus}6}M-10{sup {minus}4}M by measuring the maximum intensity of light emitted. The detection limit is about 1 10{sup {minus}6}M hydrogen peroxide. Transition metal cations at millimolar concentrations do not have any interference on the determination of hydrogen peroxide by FIA based on the enhanced chemiluminescent reaction. This technique is relatively rapid and simple, and permits measurement of up to 80 samples/hr using generally available equipment.

  15. A novel amperometric biosensor based on artichoke (Cynara scolymus L.) tissue homogenate immobilized in gelatin for hydrogen peroxide detection.

    PubMed

    Oztürk, G; Ertaş, F N; Akyilmaz, E; Dinçkaya, E; Tural, H

    2004-01-01

    A biosensor for specific determination of hydrogen peroxide was developed by using homogenized artichoke (Cynara scolymus L.) tissue in combination with a dissolved oxygen probe and applied in determination of hydrogen peroxide in milk samples. Artichoke tissue, which has catalase activity, was immobilized with gelatine by means of glutaraldehyde and fixed on a pretreated teflon membrane. The electrode response was maximum when 0.05 M phosphate buffer was used at pH 7.0 and at 30 degrees C. Upon addition of hydrogen peroxide, the electrode gives a linear response in a concentration range of 5.0-50 x 10(-5) M with a response time of 3 min. The method was also applied to the determination of hydrogen peroxide in milk samples.

  16. Fluorescence hydrogen peroxide probe based on a microstructured polymer optical fiber modified with a titanium dioxide film.

    PubMed

    Li, Dongdong; Wang, Lili

    2010-05-01

    A highly sensitive microstructured polymer optical fiber (MPOF) probe for hydrogen peroxide was made by forming a rhodamine 6G-doped titanium dioxide film on the side walls of array holes in an MPOF. It was found that hydrogen peroxide only has a response to the MPOF probe in a certain concentration of potassium iodide in sulfuric acid solution. The calibration graph of fluorescence intensity versus hydrogen peroxide concentration is linear in the range of 1.6 x 10(-7) mol/L to 9.6 x 10(-5) mol/L. The method, with high sensitivity and a wide linear range, has been applied to the determination of trace amounts of hydrogen peroxide in a few real samples, such as rain water and contact lens disinfectant, with satisfactory results.

  17. An improved G-quadruplex DNAzyme for dual-functional electrochemical biosensing of adenosines and hydrogen peroxide from cancer cells.

    PubMed

    Wang, Zong-Hua; Lu, Cai-Yu; Liu, Jing; Xu, Jing-Juan; Chen, Hong-Yuan

    2014-02-01

    A dual-functional electrochemical biosensor for adenosines and hydrogen peroxide from cancer cells was developed based on a traditional switchable electrochemical sensing format and ATP improved G-quadruplex DNAzyme as a biolabel.

  18. Massive gas embolism secondary in the use of intraoperative hydrogen peroxide: still use to lavage with this liquid?

    PubMed

    Benali, Zine El Abidine; Abdedaim, Hatim; Omari, Driss

    2013-01-01

    Cases of embolism after using hydrogen peroxide have been described in many circumstances in the operating room. Hydrogen peroxide is not more effective than other antiseptics; its potentially serious risk should not be unrecognized. The alternative use of saline seems very reasonable. The widespread use of hydrogen peroxide by practitioners is explained mainly by its antiseptic effect associated with effervescent backlash visual and auditory, but sometimes the liquid hiding behind a black hole that absorbs the life of the patient in case of inappropriate use. Diagnosis is based on clinical variations in a conscious patient at the time of use, confirmed by echocardiology if available. We related the case of a massive embolism after hydrogen peroxide use in the cleaning of infected wound with osteosynthesis material left femoral done under spinal anesthesia in a young girl of 17 years admitted after to the ICU intubated ventilated.

  19. Effect of hydrogen peroxide on ejection of cell nucleus from pigeon erythrocytes and state of membrane lipids.

    PubMed

    Devyatkin, A A; Revin, V V; Yudanov, M A; Kozlova, O V; Samuilov, V D

    2006-02-01

    The nuclei are ejected from the pigeon erythrocytes and apoptotic vesicles form in these cells in the presence of hydrogen peroxide. Hydrogen peroxide intensifies LPO processes and changes phospholipid content. The relative content of phosphatidylcholine, sphingomyelin, and phosphatidylserine decreased, while that of phosphatidylethanolamine and lisophosphatidylcholine increased. The content of unsaturated fatty acids also decreased under these conditions. Presumably, these changes in the lipid phase of the erythrocyte membrane are a mechanism preparing the cell to nucleus ejection and apoptosis.

  20. Oxidation of 2,4-dinitrophenol by hydrogen peroxide in the presence of basic oxygen furnace slag.

    PubMed

    Li, Y S; You, Y H; Lien, E T

    1999-11-01

    A treatment process was developed when basic oxygen furnace slag (BOF slag) and hydrogen peroxide were used to oxidize 2, 4-dinitrophenol from an aqueous solution. BOF slag, final waste slurry from steel making plants, contains about 12.5% by weight of ferrous oxide. In an acid solution, BOF slag can be dissociated to produce ferrous ions and react with hydrogen peroxide to produce hydroxyl radicals and oxidize 2,4-dinitrophenol. The results of the research demonstrated that the process had a significant capacity for oxidation of 2,4-dinitrophenol from the aqueous phase. Various factors critical to the oxidation of 2,4-dinitrophenol were studied, including hydrogen peroxide concentration, concentration of BOF slag, initial concentration of 2,4-dinitrophenol, and pH value of solution. Experimental results proved that 100 mg/L 2, 4-dinitrophenol and its oxidation intermediate could be totally decomposed within 60 min by 10 g/L BOF slag, 0.18 g/L hydrogen peroxide and pH 2.8 +/- 0.2. The optimum hydrogen peroxide concentration for degradation of 100 mg/L of 2,4-dinitrophenol is between 0.09 g/L and 0.18 g/L as 10 g/L BOF slag in the solution of pH 2.8 +/- 0.2. A hydrogen peroxide concentration higher than 0.18 g/L is disadvantageous to the oxidation process. The oxidation efficiency increased with the increase of BOF slag concentration at 0.18 g/L hydrogen peroxide dose. The best pH value of the solution is in the vicinity of 2.8. An oxidation reaction mechanism was proposed for predicting the concentration changes of 2, 4-dinitrophenol, ferrous ion, and hydrogen peroxide.http://link. springer-ny.com/link/service/journals/00244/bibs/37n4p427.++ +html

  1. Protective Effects of Minor Components of Curcuminoids on Hydrogen Peroxide-Treated Human HaCaT Keratinocytes.

    PubMed

    Liu, Yuh-Hwa; Lin, Yin-Shiou; Huang, Yu-Wei; Fang, Sheng-Uei; Lin, Shyr-Yi; Hou, Wen-Chi

    2016-05-11

    Hydrogen peroxide, one of the reactive oxygen species (ROS), can cause intracellular oxidative stress associated with skin aging and/or photoaging. Curcumin, a polyphenol in turmeric, has been reported to exhibit biological activity. In this study, five naturally occurring curcuminoids [curcumin, demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC), monohydroxy-DMC, and monohydroxy-BDMC] were used to investigate their protective roles against hydrogen peroxide-induced oxidative stress in the immortalized human keratinocyte cell lines (HaCaT cells). These five curcuminoids at 10 μM, but not at 5 μM, were shown to exhibit cytotoxicities toward HaCaT keratinocytes. Therefore, a 5 μM concentration of the five curcuminoids was selected for further investigations. Cells were pretreated with or without curcuminoids for 2.5 h before 24-h hydrogen peroxide (150 μM) treatments. Pretreatments with the minor components monohydroxy-DMC or monohydroxy-BDMC, but not curcumin, DMC, and BDMC, showed protective activity, elevating cell viability compared to cells with direct hydrogen peroxide treatments. Pretreatments with monohydroxy-DMC and monohydroxy-BDMC showed the best protective effects, reducing apoptotic cell populations and intracellular ROS, as demonstrated by flow cytometry, as well as reducing the changes of the mitochondrial membrane potential compared to cells with direct hydrogen peroxide treatments. The pretreatments with monohydroxy-DMC and monohydroxy-BDMC reduced c-jun and c-fos mRNA expression and p53 tumor suppressor protein expression and increased HO-1 protein expression and glutathione peroxidase (GPx) activity, respectively, compared to cells with direct hydrogen peroxide treatments. The five curcuminoids exhibited similar hydrogen peroxide-scavenging activity in vitro. It was proposed that monohydroxy-DMC and monohydroxy-BDMC could induce antioxidant defense systems better than curcumin, DMC, or BDMC could against hydrogen peroxide-induced oxidative

  2. Use of hydrogen peroxide during incubation of landlocked fall Chinook salmon eggs in vertical-flow incubators

    USGS Publications Warehouse

    Barnes, M.E.; Gaikowski, M.P.

    2004-01-01

    Six different hydrogen peroxide treatment regimes were evaluated in a series of three trials with landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs incubated in vertical-flow incubators. Six daily 15-min hydrogen peroxide treatment regimes (1,000 mg/L; 1,000 mg/L with a decrease to 500 mg/L during estimated blastopore formation; 2,000 mg/L; 2,000 mg/L with a decrease to 500 mg/L during estimated blastopore formation; 2,500 mg/L; and 2,500 mg/L with a decrease to 500 mg/L during estimated blastopore formation) were compared with daily 15-min treatments of 1,667 mg/L of formalin. Mortality at egg eye-up and fry hatch and from eye-up to hatch was significantly greater in eggs receiving the 2,500-mg/L hydrogen peroxide treatments throughout incubation and in those receiving 2,500 mg/L hydrogen peroxide with a decrease to 500 mg/L during blastopore formation than in either of the 1,000-mg/L hydrogen peroxide treatment regimes or the formalin-treated eggs in the first trial. No significant differences in mortality were observed among any of the treatments in the subsequent two trials with maximum hydrogen peroxide concentrations of 2,000 mg/L. Fungal infestations were observed primarily in the incubation trays treated at either of the 1,000-mg/L hydrogen peroxide regimens, as well as in those trays whose treatment concentrations were dropped to 500 mg/L during blastopore formation. Infestations were not observed in any of the formalin-treated trays. If minor fungal infestation is acceptable, then daily hydrogen peroxide treatments of 1,000 mg/L for 15 min would probably provide adequate fungal control compared with formalin usage.

  3. Involvement of triplet state in the photodissociation of hydrogen peroxide: experimental evidence from time-resolved EPR study

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, B.; Das, Ranjan

    The dissociation of photoexcited hydrogen peroxide to generate a pair of hydroxyl radicals is generally believed to take place in a repulsive electronic singlet state. The results presented here, based on time-resolved EPR experiments on the spin polarisation pattern of the acetone ketyl radical (CH3)2C•OH, generated on photodissociation of H2O2 in 2-propanol with a 248 nm laser light, strongly indicate significant involvement of a repulsive triplet state of excited hydrogen peroxide.

  4. Automatic dosage of hydrogen peroxide in solar photo-Fenton plants: development of a control strategy for efficiency enhancement.

    PubMed

    Ortega-Gómez, E; Moreno Úbeda, J C; Alvarez Hervás, J D; Casas López, J L; Santos-Juanes Jordá, L; Sánchez Pérez, J A

    2012-10-30

    The solar photo-Fenton process is widely used for the elimination of pollutants in aqueous effluent and, as such, is amply cited in the literature. In this process, hydrogen peroxide represents the highest operational cost. Up until now, manual dosing of H(2)O(2) has led to low process performance. Consequently, there is a need to automate the hydrogen peroxide dosage for use in industrial applications. As it has been demonstrated that a relationship exists between dissolved oxygen (DO) concentration and hydrogen peroxide consumption, DO can be used as a variable in optimising the hydrogen peroxide dosage. For this purpose, a model was experimentally obtained linking the dynamic behaviour of DO to hydrogen peroxide consumption. Following this, a control system was developed based on this model. This control system - a proportional and integral controller (PI) with an anti-windup mechanism - has been tested experimentally. The assays were carried out in a pilot plant under sunlight conditions and with paracetamol used as the model pollutant. In comparison with non-assisted addition methods (a sole initial or continuous addition), a decrease of 50% in hydrogen peroxide consumption was achieved when the automatic controller was used, driving an economic saving and an improvement in process efficiency.

  5. Simultaneous removal of nitrate, hydrogen peroxide and phosphate in semiconductor acidic wastewater by zero-valent iron.

    PubMed

    Yoshino, Hiroyuki; Tokumura, Masahiro; Kawase, Yoshinori

    2014-01-01

    The zero-valent iron (ZVI) wastewater treatment has been applied to simultaneous removal of nitrate, hydrogen peroxide and phosphate in semiconductor acidic wastewaters. The simultaneous removal occurs by the reactions performed due to the sequential transformation of ZVI under the acidic condition. Fortunately the solution pH of semiconductor acidic wastewaters is low which is effective for the sequential transformation of ZVI. Firstly the reduction of nitrate is taken place by electrons generated by the corrosion of ZVI under acidic conditions. Secondly the ferrous ion generated by the corrosion of ZVI reacts with hydrogen peroxide and generates ·OH radical (Fenton reaction). The Fenton reaction consists of the degradation of hydrogen peroxide and the generation of ferric ion. Finally phosphate precipitates out with iron ions. In the simultaneous removal process, 1.6 mM nitrate, 9.0 mM hydrogen peroxide and 1.0 mM phosphate were completely removed by ZVI within 100, 15 and 15 min, respectively. The synergy among the reactions for the removal of nitrate, hydrogen peroxide and phosphate was found. In the individual pollutant removal experiment, the removal of phosphate by ZVI was limited to 80% after 300 min. Its removal rate was considerably improved in the presence of hydrogen peroxide and the complete removal of phosphate was achieved after 15 min.

  6. Electric Response of Hydrogen Peroxide-doped Water Ices: an Analog Study for Positive Hole Currents in Rocks

    NASA Astrophysics Data System (ADS)

    Stockburger, C. C.; Keller, C. T.; Gray, A.; Sornette, J.; Udom, A.; Cruikshank, D. P.; Freund, F.

    2013-12-01

    Hydrogen peroxide-doped water ices can be viewed an analog system to igneous and high-grade metamorphic rocks, which invariably contain peroxy defects, typically Si-OO-Si, and generate positive hole charge carriers when subjected to stress. By preparing pure water ice and hydrogen peroxide-doped water ices, freezing them to -80°C, allows us to control the concentration of peroxy defects (here hydrogen peroxide molecules) and study the electrical response, when the ices are subjected to stress. Blocks of pure water ice and hydrogen peroxide-doped water ices, -80°C, were prepared. Two methods to activate peroxy bonds were used: (i) stressing one end of rectangular blocks in a hydraulic press, (ii) subjecting one part of a 2-chamber plastic tray to intense ultrasound to create a gradient of activated charge carriers. In the hydraulic press experiments the pure water ice samples produced vanishingly small currents except for occasional transients, mostly negative, during fracturing of the ice. By contrast, hydrogen peroxide-doped water ices led to significant currents, consistently positive, flowing down the stress gradients. Using ultrasound as an activation method avoids fracturing. Therefore the results are much 'cleaner', not contaminated by hard-to-control fracture-induced currents. The positive sign of the currents suggests defect electrons, generated by the break-up of peroxy bonds of hydrogen peroxide molecules embedded in the ice structure, analogous to positive hole charge carriers that are stress-activated in rocks.

  7. Use of hydrogen peroxide in scrubbing towers for odor removal in wastewater treatment plants.

    PubMed

    Charron, I; Féliers, C; Couvert, A; Laplanche, A; Patria, L; Requieme, B

    2004-01-01

    The aim of this work was to replace sodium hypochlorite (NaCIO) with hydrogen peroxide (H202) in chemical scrubbing towers, in order to avoid the formation of chlorinated species, harmful for human health. Some previous studies have already shown the ability of H2O2 to treat the hydrogen sulfide (H2S) pollution. However, an important decomposition of the oxidant was observed in the scrubbing solution (carbonates, transition metal and high pH are responsible for this decomposition) leading to high reactant consumption. Consequently, this study first focused on research into a compound able to reduce the hydrogen peroxide degradation. Experiments were conducted on a pilot unit (3,000 m3 h(-1)) in a wastewater treatment plant. The sodium silicate (Na2SiO3) proved to be a good scrubbing solution stabilizer. A very good removal of hydrogen sulfide (up to 98%) was also obtained. Finally, the study resulted in the determination of the best operating conditions to achieve both an efficient and economical process.

  8. Hydrogen peroxide production in marine bathing waters: Implications for fecal indicator bacteria mortality.

    PubMed

    Clark, Catherine D; De Bruyn, Warren J; Jakubowski, Scott D; Grant, Stanley B

    2008-03-01

    Hydrogen peroxide concentrations [H(2)O(2)] have been measured over the last two decades in multiple studies in surface waters in coastal, estuarine and oceanic systems. Diurnal cycles consistent with a photochemical production process have frequently being observed, with [H(2)O(2)] increasing by two orders of magnitude over the course of the day, from low nM levels in the early morning to 10(2)nM in late afternoon. Production rates range from <10 for off-shore ocean waters to 20-60nMh(-1) for near-shore coastal and estuarine environments. Slow night-time loss rates (<10nMh(-1)) have been attributed to biological and particle mediated processes. Diurnal cycles have also frequently been observed in fecal indicator bacteria (FIB) levels in surf zone waters monitored for microbial water quality. Measured peak peroxide concentrations in surface coastal seawaters are too low to directly cause FIB mortality based on laboratory studies, but likely contribute to oxidative stress and diurnal cycling. Peroxide levels in the surf zone may be increased by additional peroxide production mechanisms such as deposition, sediments and stressed marine biota, further enhancing impacts on FIB in marine bathing waters.

  9. Propanal synthesis from aqueous propylene glycol/hydrogen peroxide on a Ru/alumina catalyst

    SciTech Connect

    Disselkamp, Robert S.; Harris, Benjamin D.; Patel, Jayshribe N.; Hart, Todd R.; Peden, Charles HF

    2008-05-01

    The conversion of polyol materials, including 1,2-diols, into higher commodity chemicals is actively being pursued by many researchers. Here we report the production of propanal from propylene glycol and hydrogen peroxide using a Ru/alumina catalyst. Experiments were conducted by adding up to four peroxide equivalents under steady-state reflux conditions at 371 K. The product propanal and its subsequent reaction product with substrate, 1,3-dioxolane-2-ethyl-4-methyl, was observed to be an intermediate achieving a maximum concentration of 3% of substrate. Buffering using Mg(OH)2 at pH~10 resulted in propanal formation, whereas buffering at similar pH using Na2HSO4 did not, from which we propose that magnesium acts as a promoter in the reaction. The mechanism appears to be a dehydration to enol, followed by rearrangement to product. Experiments utilizing Ru/carbon did not yield any propanol suggesting that the acidic sites of alumina aid the dehydration reaction. To our knowledge, this represents the first time hydrogen peroxide has been used in an alcohol dehydration reaction.

  10. A Comparison between Lime and Alkaline Hydrogen Peroxide Pretreatments of Sugarcane Bagasse for Ethanol Production

    NASA Astrophysics Data System (ADS)

    Rabelo, Sarita C.; Filho, Rubens Maciel; Costa, Aline C.

    Pretreatment procedures of sugarcane bagasse with lime (calcium hydroxide) or alkaline hydrogen peroxide were evaluated and compared. Analyses were performed using 2 × 2 × 2 factorial designs, with pretreatment time, temperature, and lime loading and hydrogen peroxide concentration as factors. The responses evaluated were the yield of total reducing sugars (TRS) and glucose released from pretreated bagasse after enzymatic hydrolysis. Experiments were performed using the bagasse as it comes from an alcohol/ sugar factory and bagasse in the size range of 0.248 to 1.397 mm (12-60 mesh). The results show that when hexoses and pentoses are of interest, lime should be the pretreatment agent chosen, as high TRS yields are obtained for nonscreened bagasse using 0.40 g lime/g dry biomass at 70 °C for 36 h. When the product of interest is glucose, the best results were obtained with lime pretreatment of screened bagasse. However, the results for alkaline peroxide and lime pretreatments of nonscreened bagasse are not very different.

  11. A high-throughput microtiter plate based method for the determination of peracetic acid and hydrogen peroxide.

    PubMed

    Putt, Karson S; Pugh, Randall B

    2013-01-01

    Peracetic acid is gaining usage in numerous industries who have found a myriad of uses for its antimicrobial activity. However, rapid high throughput quantitation methods for peracetic acid and hydrogen peroxide are lacking. Herein, we describe the development of a high-throughput microtiter plate based assay based upon the well known and trusted titration chemical reactions. The adaptation of these titration chemistries to rapid plate based absorbance methods for the sequential determination of hydrogen peroxide specifically and the total amount of peroxides present in solution are described. The results of these methods were compared to those of a standard titration and found to be in good agreement. Additionally, the utility of the developed method is demonstrated through the generation of degradation curves of both peracetic acid and hydrogen peroxide in a mixed solution. PMID:24260173

  12. A high-throughput microtiter plate based method for the determination of peracetic acid and hydrogen peroxide.

    PubMed

    Putt, Karson S; Pugh, Randall B

    2013-01-01

    Peracetic acid is gaining usage in numerous industries who have found a myriad of uses for its antimicrobial activity. However, rapid high throughput quantitation methods for peracetic acid and hydrogen peroxide are lacking. Herein, we describe the development of a high-throughput microtiter plate based assay based upon the well known and trusted titration chemical reactions. The adaptation of these titration chemistries to rapid plate based absorbance methods for the sequential determination of hydrogen peroxide specifically and the total amount of peroxides present in solution are described. The results of these methods were compared to those of a standard titration and found to be in good agreement. Additionally, the utility of the developed method is demonstrated through the generation of degradation curves of both peracetic acid and hydrogen peroxide in a mixed solution.

  13. Effects of 15% Carbamide Peroxide and 40% Hydrogen Peroxide on the Microhardness and Color Change of Composite Resins

    PubMed Central

    Kamangar, Sedighe Sadat Hashemi; Kiakojoori, Kiana; Mirzaii, Mansoore; Fard, Mohammad Javad Kharazi

    2014-01-01

    Objective: The aim of this study was to determine the effects of 40% hydrogen peroxide and 15% carbamide peroxide on microhardness and color change of a silorane-based composite resin in comparison with two methacrylate-based composites. Materials and Methods: Fifty-four disc-shaped specimens (A3 shade) were fabricated of Filtek P90 (P90), Filtek Z350XT Enamel (Z350) and Filtek Z250 (Z250) (3MESPE) (n=18). The samples of each composite were randomly divided into three subgroups of 6. The control subgroups were immersed in distilled water; the test groups were exposed to Opalescence Boost (OB) once; and Opalescence PF (OP) (Ultradent) for two weeks. Vickers microhardness testing and a spectrophotometric analysis of the color of samples were performed before and after each intervention. Results: The baseline microhardness of P90 was significantly lower than that of the other two composites (P=0.001), but no difference was found between Z250 and Z350 in this respect (P=0.293). Bleaching treatments significantly decreased the microhardness of Z250 and Z350 (P< 0.001), but no change was observed in P90 test and control subgroups (P> 0.05). No significant difference was detected between the two types of bleaching (P>0.05). After bleaching with OB, ΔE value was measured to be 3.12(1.97), 3.31(1.84) and 3.7(2.11) for P90, Z250 and Z350, respectively. These values were 5.98(2.42), 4.66(2.85) and 4.90(2.78) after bleaching with OP with no significant difference. Conclusion: Bleaching decreased the microhardness of methacrylate-based but not silorane-based composites. Although no significant differences were found in ΔE of composites, ΔE of all groups did not remain in the clinically acceptable range after bleaching except for P90 after bleaching with 40% H2O2 (ΔE < 3.3). PMID:24910696

  14. Hydrogen peroxide detection with high specificity in living cells and inflamed tissues

    PubMed Central

    Rong, Lei; Zhang, Chi; Lei, Qi; Hu, Ming-Ming; Feng, Jun; Shu, Hong-Bing; Liu, Yi; Zhang, Xian-Zheng

    2016-01-01

    Hydrogen peroxide (H2O2) detection in biological systems is of significant importance, which act as critical second messenger in fundamental biological processes. Here, we report on a chemoselective fluorescent naphthylimide peroxide probe (NPP) for the H2O2 detection in vitro and in vivo. NPP is a phenylboronic acid-caged chromophore that selectively responds to H2O2 through a self-immolate mechanism. NPP exhibited high sensitivity and selectivity to H2O2 with distinctive fluorescence change due to the excellent two-photon excitation property, which permits the facile detection of inflammation produced H2O2 and offers chance to monitor the inflammatory stages in diseased cells. PMID:27482463

  15. Hydrogen peroxide detection with high specificity in living cells and inflamed tissues.

    PubMed

    Rong, Lei; Zhang, Chi; Lei, Qi; Hu, Ming-Ming; Feng, Jun; Shu, Hong-Bing; Liu, Yi; Zhang, Xian-Zheng

    2016-12-01

    Hydrogen peroxide (H2O2) detection in biological systems is of significant importance, which act as critical second messenger in fundamental biological processes. Here, we report on a chemoselective fluorescent naphthylimide peroxide probe (NPP) for the H2O2 detection in vitro and in vivo. NPP is a phenylboronic acid-caged chromophore that selectively responds to H2O2 through a self-immolate mechanism. NPP exhibited high sensitivity and selectivity to H2O2 with distinctive fluorescence change due to the excellent two-photon excitation property, which permits the facile detection of inflammation produced H2O2 and offers chance to monitor the inflammatory stages in diseased cells.

  16. Hydrogen peroxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The safety of fresh and fresh-cut produce available in salad-bar operations and supermarkets is a concern because of foodborne illness arising from consumption of fruits and vegetables that are surface contaminated with enteric pathogens. Field-packed produce are not generally washed because of the ...

  17. Negative hydrogen ion sources for accelerators

    SciTech Connect

    Moehs, D.P.; Peters, J.; Sherman, J.; /Los Alamos

    2005-08-01

    A variety of H{sup -} ion sources are in use at accelerator laboratories around the world. A list of these ion sources includes surface plasma sources with magnetron, Penning and surface converter geometries as well as magnetic-multipole volume sources with and without cesium. Just as varied is the means of igniting and maintaining magnetically confined plasmas. Hot and cold cathodes, radio frequency, and microwave power are all in use, as well as electron tandem source ignition. The extraction systems of accelerator H{sup -} ion sources are highly specialized utilizing magnetic and electric fields in their low energy beam transport systems to produce direct current, as well as pulsed and/or chopped beams with a variety of time structures. Within this paper, specific ion sources utilized at accelerator laboratories shall be reviewed along with the physics of surface and volume H{sup -} production in regard to source emittance. Current research trends including aperture modeling, thermal modeling, surface conditioning, and laser diagnostics will also be discussed.

  18. Localization of hydrogen peroxide accumulation and diamine oxidase activity in pea root nodules under aluminum stress.

    PubMed

    Sujkowska-Rybkowska, Marzena; Borucki, Wojciech

    2014-02-01

    Aluminum (Al) is one of the environmental stressors that induces formation of reactive oxygen species (ROS) in plants. Hydrogen peroxide (H2O2) and H2O2-generated apoplast diamine oxidase (DAO) activity were detected cytochemically via transmission electron microscopy (TEM), in pea (Pisum sativum L.) root nodules exposed to high (50 μM AlCl3, for 2 and 24h) Al stress. The nodules were shown to respond to Al stress by disturbances in infection thread (IT) growth, bacteria endocytosis, premature degeneration of bacteroidal tissue and generation of H2O2 in nodule apoplast. Large amounts of peroxide were found at the same sites as high DAO activity under Al stress, suggesting that DAO is a major source of Al-induced peroxide accumulation in the nodules. Peroxide distribution and DAO activity in the nodules of both control plants and Al-treated ones were typically found in the plant cell walls, intercellular spaces and infection threads. However, 2 h Al treatment increased DAO activity and peroxide accumulation in the nodule apoplast and bacteria within threads. A prolonged Al treatment (24 h) increased the H2O2 content and DAO activity in the nodule apoplast, especially in the thread walls, matrix and bacteria within infection threads. In addition to ITs, prematurely degenerated bacteroids, which occurred in response to Al, were associated with intense staining for H2O2 and DAO activity. These results suggest the involvement of DAO in the production of a large amount of H2O2 in the nodule apoplast under Al stress. The role of reactive oxygen species in pea-Rhizobium symbiosis under Al stress is discussed. PMID:24246127

  19. Vibrational spectra and molecular dynamics of hydrogen peroxide molecules at quartz/water interfaces

    NASA Astrophysics Data System (ADS)

    Lv, Ye-qing; Zheng, Shi-li; Wang, Shao-na; Yan, Wen-yi; Zhang, Yi; Du, Hao

    2016-06-01

    The influence of H2O2 on the water vibration at quartz interface was examined using sum-frequency generation (SFG) spectroscopy, and the effect of H2O2 concentration has been systematically studied. Further, the number density and radical distribution of water molecules, H2O2 molecules, and quartz surface silanol groups were calculated using molecular dynamics (MD) simulation to provide molecular level interpretation for the SFG spectra. It is concluded from this study that the hydrogen peroxide molecules prefers to donate H-bonds to the in-plane silanol groups rather than accepting H-bonds from out-of-plane silanol groups, as evidenced by the strengthening of the peak located at 3400 cm-1 assigned to "liquid-like" hydrogen-bonding network. The SFG results have been supported by the MD calculation results, which demonstrate that the relative intensity of the peak located at 3400 cm-1 to that of located at 3200 cm-1 increases monotonously with the increase in the number of hydrogen peroxide in the first hydration shell of silanol.

  20. Hydroxy acetone and lactic acid synthesis from aqueous propylene glycol/hydrogen peroxide catalysis on Pd-black

    SciTech Connect

    Disselkamp, Robert S.; Harris, Benjamin D.; Hart, Todd R.

    2008-07-20

    The production of polyol chemicals is of increasing interest as they are obtained from the catalytic processing of biological feedstock materials, which also is becoming more prevalent. A case in point is glycerol production, formed as a byproduct in biodiesel catalytic processing. Here we report the reaction of a simple 1,2-diol, propylene glycol, with hydrogen peroxide and a Pd-black catalyst under reflux conditions at 368 K. The experiments were performed by either co-addition of hydrogen peroxide with air sparging, or addition of hydrogen peroxide alone, each yielding hydroxy acetone (HA) and acetic acid (AA) products, with a lesser amount of lactic acid (LA) formed. Product conversion data at near neutral pH versus hydrogen peroxide equivalents added relative to substrate is presented. Hydrogen peroxide addition without air sparging at 5 equivalents resulted in 65% conversion with an HA:AA molar ratio of 2:1. Conversely, hydrogen peroxide addition with air sparging at only 0.75 equivalents resulted in 40% conversion with an HA:AA ratio of 3:1. From this it is concluded that although the product distribution in these chemistries is somewhat unchanged by air sparging, it is surprising that the amount of reactive oxygen is greatly enhanced with co-addition of O2/H2O2. Additional studies have revealed the amount of LA formed can be enhanced under acidic conditions (pH=1.5 compared to pH=8.5), such that 26% of total product formation is LA. Since hydrogen peroxide is an environmentally clean reagent and becoming more cost effective to use, this work may guide future applied investigations into polyol chemical syntheses.