Stability Of Peroxide Research Articles

Unusual Stabilization of Zinc Peroxide by Manganese Oxide: Mechanistic Understanding by Temperature-Dependent EPR Studies

Nanocrystalline zinc peroxide is passivated against further oxidation by the addition of minute, substoichiometric amounts of potassium permanganate, which also endows it with increased thermal sta...

A multiple‐site field study of stabilized hydrogen peroxide for drinking water disinfection

AbstractThis study examined the impact of changing the secondary disinfectant from chlorine to a stabilized hydrogen peroxide (SHP) in three full‐scale drinking water treatment plants serving small communities in the provinces of Ontario and Newfoundland, Canada. In all three communities, the SHP residuals were maintained within the limits specified by local regulators, with the exception of one of the sites in Newfoundland, where residuals were outside these limits on several occasions during the study. Following the transition to the SHP system, total coliforms and Escherichia coli consistently tested negative (nondetected) in all cases. Switching to the SHP system reduced concentrations of total trihalomethanes to 22–44 μg/L and total haloacetic acids to 47–70 μg/L, corresponding to 72 ± 9 and 67 ± 11% reductions, respectively. The present study indicated that changing the secondary disinfectant to SHP did not negatively affect the polyvinyl chloride and ductileiron pipes in the distribution systems studied.

Trifluoromethyl and benzyl ether side groups containing novel sulfonated co-poly(ether imide)s: Application in microbial fuel cell

A new diamine monomer namely 4,4′-((2′,5′-bis(benzyloxy)-3,3′'-bis(trifluoromethyl)-[1,1′:4,4′'-terphenyl]-4,4′'-diyl)bis(oxy))dianiline (TADBE) was prepared. A series of sulfonated co-poly(ether imide)s was synthesized using this diamine as one of the co-monomers along with 4,4′-diaminostilbene-2,2′-disulfonic acid (DSDSA) on reaction with a six-membered dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride (NTDA). The degree of sulfonation (DS, 60-90) of the copolymers was controlled by varying the feed ratio of TADBE/DSDSA and the obtained copolymers were designated as DBN-XX (XX = 60, 70, 80 and 90, which signifies the DSDSA feed percentage). The copolymer structures and compositions were confirmed by NMR and FTIR analysis. Membranes were prepared through solution casting route using dimethyl sulfoxide as solvent followed by high-temperature annealing. The membranes showed high thermal (e.g., DBN-60, Td10 ∼327 °C) and mechanical stabilities (e.g., DBN-60, tensile strength ∼94 MPa), good hydrolytic stability (e.g., DBN-60, >99 retain wt%) and low water uptake (e.g., DBN-60, ∼17 wt% at 80 °C). Polymer composites were prepared by loading different weight percentages of cerium oxide (2.5, 5 and 7.5 wt%, respectively) to enhance the peroxide stability of the copolymer DBN-90 with high DS value. TEM and AFM studies of the pristine membranes confirmed a well phase separated morphology and this was further supported from SAXS profiles. The proton conductivity (e.g., DBN-90, ∼244 mS cm−1) and microbial fuel cell performance (e.g., DBN-90, power density ∼576 mW m−2) of the membranes were comparable to Nafion® 117 (power density ∼563 mW m−2) under similar experimental conditions.

Research on the effect of resin on the thermal stability of hydrogen peroxide

Resin is widely used in hydrogen peroxide purification process, but it has a certain role in the decomposition of hydrogen peroxide. The effect of resin on decomposition characteristics of hydrogen peroxide was investigated in this study. Based on the Chinese national standard GB/T1616, hydrogen peroxide stability test was established, and the effect of resin on the stability of hydrogen peroxide was investigated. The thermal stability of hydrogen peroxide and the effect of resin on the samples were obtained by DSC calorimeter. The adiabatic simulation experiment was carried out by VSP2 calorimeter, and the thermal runaway reaction characteristics of hydrogen peroxide-resin system under adiabatic conditions were obtained. By fitting regression of the adiabatic calorimetric experimental data, the kinetic parameters of the experimental system were obtained, and the TMRad was calculated to be 5.9 h. The experimental results show that the stability of hydrogen peroxide decreases obviously with the addition of resin, and the uncontrolled decomposition of hydrogen peroxide easily occurs under adiabatic conditions, which has great potential safety hazards.

A Simple, Green and Fast Ultraviolet Spectrophotometric Method for the Carbamide Peroxide Determination in Dental Whitening Products

Background: The carbamide peroxide is the most commonly active ingredient used for home dental whitening products, its quantification in pharmaceutical products is of extreme importance due to the relation with the products potency and the previously related low carbamide peroxide stability. Once, there is only one official carbamide peroxide determination based on iodometric titration, this method is time-consuming and generates a lot of residues. The aim of this study was to carry out development and validation of a simple and fast ultraviolet spectrophotometer assay to quantify an innovative dental whitening gel. Methods: The proposed method was validated according international conference on harmonization guideline. Procedure is based on the iodide/iodine redox chemistry; iodine released through the action of hydrogen peroxide of carbamide peroxide with ultraviolet detection at 350 nm. Results: The procedure was linear in the concentration range of 1.0-4.0 µg/mL, specific to the excipients, robust for the evaluated parameters (variation of wavelength (± 5 nm); reagent addition (± 10%)), showing the results of RSD 1.88 and 0.39% respectively. Repeatability precision was RSD = 1.42%, with accurate RSD = 2.15% by adding reference solution. The assay used only water as solvent for sample preparation. In comparison to the pharmacopeial method, the latter is more time-consuming, as it generates a lot of residues, and it could not quantify small CP dosages. Conclusion: Thus, the proposed method was proved to be suitable to determine carbamide peroxide during the development and characterization of nanoparticle formulations in the present study.

Stability Evaluation of Hydrogen Peroxide Uptake Samples from Monoclonal Antibody Drug Product Aseptically Filled in Vapor Phase Hydrogen Peroxide-Sanitized Barrier Systems: A Case Study.

During the manufacture of a monoclonal antibody drug product, which was aseptically filled within a vapor phase hydrogen peroxide-sanitized isolator, samples were taken to investigate the hydrogen peroxide uptake behaviors. Surprisingly, the samples had no detectable hydrogen peroxide (most results below the limit of detection). This finding was later attributed to hydrogen peroxide decomposition after the samples were stored frozen at -20°C for two weeks before testing. This case study highlights the criticality of storage conditions for hydrogen peroxide-containing samples and summarizes an investigation on hydrogen peroxide stability in water and in three monoclonal antibody solutions having a wide protein concentration range (30-200 mg/mL). Samples were stored at three temperatures (-70°C, -20°C, or 2-8°C) for up to 28 days to assess the impact of protein concentration and storage temperature on hydrogen peroxide decomposition rates. Hydrogen peroxide degraded slightly more rapidly with increasing protein concentration independent of storage condition. When stored at -20°C, hydrogen peroxide was least stable and degraded faster than when stored at 2-8°C. Hydrogen peroxide was most stable when the samples were stored at -70°C. Overall, this case study brings the hydrogen peroxide stability issue to the attention of process development scientists and engineers and offers a valuable lesson learned during process development.LAY ABSTRACT: The use of vapor phase hydrogen peroxide as a sanitizing agent for isolator and cleanroom decontamination has become common in recent years. Because of the potential impact of residual hydrogen peroxide on biopharmaceutical product quality, hydrogen peroxide uptake behaviors and mechanisms during the manufacturing process within these barriers need to be evaluated and understood. Samples taken from various small-scale and manufacturing-scale hydrogen peroxide uptake studies are often stored frozen before testing. This case study reports an important and interesting finding about hydrogen peroxide stability in samples collected for hydrogen peroxide uptake investigation, and it demonstrates the relationship between hydrogen peroxide stability and storage temperature, storage duration, and monoclonal antibody concentration. The approach and outcome of this study are expected to benefit scientists and engineers who develop biologic product manufacturing processes by providing a better understanding of drug product process challenges and appropriate sample storage.

Selective synthesis and stabilization of peroxidesviaphosphine oxides

MEKPO (methyl ethyl ketone peroxide) and other peroxides can be synthesized selectively and stabilized as hydrogen-bonded phosphine oxide adducts.

Stabilized hydrogen peroxide for the remediation of hydrocarbons and MTBE in high temperature and saline groundwater

AbstractA field pilot‐scale test was conducted to determine if the use of citric acid‐stabilized hydrogen peroxide (H2O2) is effective in reducing dissolved concentrations of petroleum hydrocarbon compounds (PHCs) and the additive methyl tert‐butyl ether (MTBE) in impacted high salinity groundwater. The test was carried out adjacent to an operational hydrocarbon fuel facility in Western Saudi Arabia. The pilot test was based on the results of laboratory tests, which suggested that hydrogen peroxide stabilized with citric acid (C6H8O7) would enhance the degradation of the dissolved PHCs and associated MTBE within a saline groundwater. A 7.5 weight percent hydrogen peroxide solution was injected into a series of injection wells positioned to target a PHC‐impacted plume within an unconfined aquifer. The plume contains total benzene, toluene, ethylbenzene, and xylenes (BTEX) at concentrations up to 6,890 micrograms per liter (μg/L). The MTBE concentration within the groundwater was detected at concentrations of up to 55,182 μg/L, whereas the groundwater salinity was approximately 7,000 milligrams per liter (mg/L). A total of 9,012 liters of citric acid‐stabilized hydrogen peroxide solution was injected over three events spaced over a 1‐month period. The results of the pilot test indicated that injection of stabilized hydrogen peroxide was effective in reducing the concentration of dissolved PHCs within the plume, including BTEX and other aromatic hydrocarbons. The average concentration decrease for total BTEX was 72% with up to 97.4% reduction being measured in a sample collected from one key monitoring well during the treatment period. MTBE was also effectively treated during the pilot test with an average MTBE degradation of 50% being realized during the test and up to 86% concentration decrease being measured in some groundwater samples. While reductions in MTBE concentrations were noted, no increase in tertiary butyl alcohol was measured, which is a promising finding. The general water quality did not fluctuate significantly between pre‐ and postinjection with the pH, oxidation–reduction potential, and dissolved oxygen remaining relatively constant. The dissolved iron, nitrate, and sulfate concentrations vary during the injection period with nitrate decreasing to below detection limits following the final injection, whereas sulfate decreased in two of the three monitoring wells following the injection. Dissolved iron concentrations remained relatively constant in two of the three monitoring wells (NJBP45 and NJBP46) during the injection events, whereas dissolved iron in monitoring well NJBP44 decreased from a baseline concentration of 1.03 μg/L to 0.09 μg/L, suggesting that the ferrous iron in solution was being oxidized to ferric iron. Measurements of the preinjection microbiological community indicated that the community is diverse within the injection area based on deoxyribonucleic acid extraction by polymerase chain reaction as well as sequencing and clustering. Subsequent analyses of the microbiological community postinjection indicated that the community diversity and biomass was reduced with a shift to a more aerobic population, at least over the short term. Results of compound specific isotope analyses are consistent with the concentration data and show petroleum hydrocarbon and MTBE was degraded by the citric acid‐stabilized hydrogen peroxide treatment.

Oxygen selective membrane based on perfluoropolyether for Li-Air battery with long cycle life

Although Li-air batteries have superhigh theoretical energy density, their practical application is still a big challenge especially when operated in regular air. At this point, it is crucial to avoid side reactions induced by the moisture in the air. Thus, an oxygen selectively permeable membrane is desirable. Herein, we introduce an oxygen-permeating waterproof membrane based on perfluoropolyether (PFPE), a non-volatile hydrophobic liquid compound with high oxygen solubility. With protection of the PFPE-wetted Celgard membrane, the stability of both lithium metal and lithium peroxide is significantly improved. Meanwhile, the evaporation of organic electrolyte solvent is greatly suppressed. As a result, the Li-air cell is able to run 144 cycles over 58 days in ambient air with ~ 30% relative humidity.

Recent Advances in the Direct Synthesis of Hydrogen Peroxide Using Chemical Catalysis—A Review

Hydrogen peroxide is an important chemical of increasing demand in today’s world. Currently, the anthraquinone autoxidation process dominates the industrial production of hydrogen peroxide. Herein, hydrogen and oxygen are reacted indirectly in the presence of quinones to yield hydrogen peroxide. Owing to the complexity and multi-step nature of the process, it is advantageous to replace the process with an easier and straightforward one. The direct synthesis of hydrogen peroxide from its constituent reagents is an effective and clean route to achieve this goal. Factors such as water formation due to thermodynamics, explosion risk, and the stability of the hydrogen peroxide produced hinder the applicability of this process at an industrial level. Currently, the catalysis for the direct synthesis reaction is palladium based and the research into finding an effective and active catalyst has been ongoing for more than a century now. Palladium in its pure form, or alloyed with certain metals, are some of the new generation of catalysts that are extensively researched. Additionally, to prevent the decomposition of hydrogen peroxide to water, the process is stabilized by adding certain promoters such as mineral acids and halides. A major part of today’s research in this field focusses on the reactor and the mode of operation required for synthesizing hydrogen peroxide. The emergence of microreactor technology has helped in setting up this synthesis in a continuous mode, which could possibly replace the anthraquinone process in the near future. This review will focus on the recent findings of the scientific community in terms of reaction engineering, catalyst and reactor design in the direct synthesis of hydrogen peroxide.

Experimental and theoretical investigations of methyl formate oxidation including hot β-scission

Abstract Recently the possibility of hot β-scission pathways gained attention. These reactions give a shortcut during the important fuel consumption phase in combustion processes leading from H-atom abstraction directly to the β-scission products without fuel radical thermalization. Methyl formate (MF) was shown to be prone to hot β-scission due to a low β-scission barrier height. Furthermore, MF as smallest methyl ester can be considered as biodiesel surrogate and it is an important intermediate product during combustion of various ethers. In this work a predominantly ab-initio derived detailed kinetic model of MF combustion is developed including hot β-scission pathways and compared to a sophisticated literature model based on classical estimation methods. For this, new stoichiometric MF in air ignition delay time measurements in a shock tube and a rapid compression machine over a wide temperature range (790 K–1250 K) and pressures of 10, 20 and 40 bar served as validation targets. The experimental ignition delay times (IDT) show Arrhenius type behavior in both facilities at all conditions. The newly developed quantum-based model catches the pressure dependency and low-temperature reactivity well although overpredicting the IDT at higher temperatures. It was found that hot β-scission is the major depletion pathway of formate group-centered MF radicals. This, however, does not change the overall reactivity of MF combustion due to the low stability of the alkyl peroxide (RO2) at the formate group. For species with competing thermal β-scission and RO2 formation, however, hot β-scission may have a significant impact.

Continuous Platform to Generate Nitroalkanes On-Demand (in situ) using Peracetic Acid-Mediated Oxidation in a PFA Pipes-in-Series Reactor.

The synthetic utility of the aza-Henry reaction can be diminished on scale by potential hazards associated with the use of peracid to prepare nitroalkane substrates, and the nitroalkanes themselves. In response, a continuous and scalable chemistry platform to prepare aliphatic nitroalkanes on-demand is reported, using the oxidation of oximes with peracetic acid and direct reaction of the nitroalkane intermediate in an aza-Henry reaction. A uniquely designed pipes-in-series plug flow tube reactor addresses a range of process challenges including stability and safe handling of peroxides and nitroalkanes. The subsequent continuous extraction generates a solution of purified nitroalkane which can be directly used in the following enantioselective aza-Henry chemistry to furnish valuable chiral diamine precursors in high selectivity, thus, completely avoiding isolation of potentially unsafe low molecular weight nitroalkane intermediate. A continuous campaign (16 h) established that these conditions were effective in processing 100 g of the oxime and furnishing 1.4 L of nitroalkane solution.

Stabilization of Zinc Peroxide in the Combined Process of Granulation and Encapsulation

A combined procedure of zinc peroxide granulation and encapsulation in one technological stage has been developed, which ensures the stabilization of ZnO2 by forming a coating on the surface of the product granules. It is shown that the use of sodium polyphosphate in a combined process of granulation and encapsulation as encapsulating agents with the concentration in the initial solution of 1% allows obtaining a capsular product, which is significantly more resistant to the action of wet carbon dioxide than a nonencapsulated analogue.

Carbon Black Supported Highly Stable and Active Electrocatalysts for ORR in Polymer Electrolyte Membrane Fuel Cells

Exploring low-cost and highly efficient non-precious metal electrocatalysts toward oxygen reduction reaction is crucial for the development of fuel cells. Pyrolyzed Fe/N/C electrocatalysts have received attention in recent years as a cathode catalyst for oxygen reduction reaction (ORR) in the polymer electrolyte fuel cell (PEFC). These kinds of non-precious metals electrocatalysts had shown high activity and stability in both acidic and alkaline media. [1, 2]. Herein, we organized our significant advances in performance of Fe/N/C catalysts and their applications in low temperature fuel cells: We synthesized N-doped electrocatalysts using melamine as nitrogen precursor, ferric chloride as an iron precursor and oxidized carbon black kJ600 as support by solvothermal method. The final catalyst synthesized at 800°C (SNW-Fe/N/C@800°C) exhibited microporous structure with Brunauer−Emmett−Teller (BET) surface area up to 791 m2g-1 after second heat treatment. The catalyst exhibits high ORR activity (0.64 mA mg-1 at 1 V vs RHE, about half of Pt/C catalyst), stability and low percentage of hydrogen peroxide (% H2O2 < 1.5%) in O2-saturation 0.1 M NaOH solution. The alkaline anion exchange membrane fuel cell (AEMFC) test was performed by using SNW-Fe/N/C@800°C as cathode catalyst demonstrates a high power density of 266 mW cm-2.We study the effect of active nitrogen species on ORR performance through comparison of Fe/N/C electrocatalysts in acidic and alkaline solution. These catalysts are synthesized from different rich-nitrogen polymers. We observed that pyridinic N is very important for oxygen reduction reaction through XPS analysis, especially in alkaline electrolyte. The sensitivity of these three catalysts to acidity/alkalinity highly depends on percentage of pyridinic N and found the reverse order of ORR activity between acidic and alkaline mediaWe designed a facile method for the synthesis of ORR catalysts with iron nanoparticles encapsulated in bamboo like structure of N-doped carbon nanotubes. Finally, pyrolyzed catalyst (Bg-CA-M)-Fe-C-800°C exhibited the efficient ORR performance with the onset potential 1.10 V, half-wave potential 0.93V, 4 electrons transfer number per oxygen molecule and high durability, as well as high ethanol tolerance in alkaline solution. (XPS measurements revealed that ORR activities of catalysts directly correlate with pyridinic and pyrrolic nitrogen active species. The direct ethanol fuel cell (DEFC) with (Bg-CA-M)-Fe-C as cathode catalyst displayed 64 mW cm-2 peak power density.

An Assessment of the Influence of Silver Stabilized Hydrogen Peroxide on the Eggshell Condition

The aim of the study was to assess the condition of eggshells hygienised with an silver stabilized hydrogen peroxide of different concentrations. Eggs were treated with a solution of the preparation and stored for four weeks. In preliminary investigations the elastic deformation of eggshells was measured and analysed in order to determine the influence of a preparation concentrated at 0.01-3% on the eggshell strength. The research proved that a preparation concentrated at 1-3% significantly reduced the eggshell strength. At the next stage of the research, having excluded the high concentrations with a negative effect on eggshell strength, i.e. 1-3%, the experiment was conducted again. It was followed by a microbiological analysis in which the total count of aerobic bacteria, yeasts, moulds ad also bacteria from the Pseudomonas genus and Enterobacteriaceae family were measured. The investigations confirmed that the preparation concentrated at 0.01-0.9% did not have a significant influence on eggshell strength. Hygienisation in solutions concentrated at 0.01-0.9% caused complete inactivation of bacteria of the Enterobacteriaceae family, yeasts and moulds. Immediately after treatment with the preparation concentrated at 0.3% the count of aerobic bacteria and the bacteria of the Pseudomonas genus decreased by 1.9 log CFU/g and 0.7 log CFU/g, respectively. The hygienisation of eggs with the preparation concentrated at 0.9% and storing them for four weeks under controlled conditions reduced the count of aerobic bacteria by 1.9 log and the count of Pseudomonas bacteria by 1.7 log, as compared with the reference sample.

Comparative evaluation of baseline cleanliness of food contact surfaces in fishery based microenterprise units by ATP-Bioluminescence and conventional microbiological methods

The baseline cleanliness of food contact surfaces namely floor, working tables, workers’ hands, utensils and machinery of a fishery-based microenterprise were examined by traditional microbiological swab analysis method and ATP-bioluminescence method. The study showed that swab results, measured in relative light unit which is proportional to total recovered ATP, did not have significant correlation with standard method of microbiological swab in the adjacent sites of equal area. The study also examined the bactericidal efficiency of selected commercially available sanitisers and the effect of treatment was found to be significantly different from each other. Analysis of percentage reduction of bacterial load on food contact surfaces showed that commercially available stabilised hydrogen peroxide was more effective than sodium hypochlorite used in the food industries (p&lt;0.05).

Experimental study on the thermal runaway of hydrogen peroxide with in-/organic impurities by a batch reactor

Hydrogen peroxide, as a very versatile reagent for many industrial processes, has caused many accidents in recent years. Therefore, understanding the thermal hazards of hydrogen peroxide with or without impurities is essential for the prevention of fire and explosion accidents. In this work, batch reactor tests were conducted to study the thermal runaway behavior of hydrogen peroxide under the contaminations of Fe3+ ion, formic/acetic acid and ethanol/acetone. Experimental results revealed that the thermal runaway risk of H2O2 increased significantly with increasing initial temperature and Fe3+ ion concentration. Comparatively, the potential risk of organic impurities on the thermal stability of hydrogen peroxide was found to be much larger, because several violent explosions were measured resulting from a series of rapid and complicated decomposition reactions. The explosion severity of H2O2 with organic matters followed acetone > ethanol > formic acid > acetic acid. In addition, a modified runaway scenario characterized as adiabatic temperature increase and time to maximum rate was briefly described to theoretically evaluate the thermal risk of H2O2 decomposition. This scenario was found to be valid to estimate thermal runaway hazards. These results improve our understanding of thermal runaway behavior and explosion risk of H2O2 with incompatible impurities.

A novel hydrogen peroxide stabilizer in descaling process of metal surface

A recently developed descaling process for metal surface, which utilizes sulphuric, hydrofluoric acid and hydrogen peroxide (H2O2), has attracted great attention in consideration of eco-friendly sustainable process development. However, the intrinsic presence of metal ions, especially Fe(III), dramatically accelerates H2O2 decomposition, resulting in undesirable economic losses and even paralysis of operation. In this study, the stability of H2O2 in aqueous descaling acid was assessed by varying the ferric content from 0 to 30 g/L and the temperature from 32 to 45 °C. The results showed that any minor fluctuation in either factors causes a big attenuation in the life span of H2O2, necessitating the addition of a stabilizer. Thereby, a comprehensive screening test for potential stabilizers was carried out for an attempt to decelerate the H2O2 decomposition. Among all prospects, 2-anilinoethanol (AE, 100 mg/L) showed the most prominent stabilizing potential by successfully extending the half-life of peroxide by a factor of 2.66 compared to a controlled condition. The feasibility of AE as a stabilizer was further explored by elucidating its fate with GC-MS and IC analyses. A series of aromatics and short-chain organic acids was identified as the reaction intermediates. Aniline, with great H2O2 stabilizing capacity, was a predominant byproduct, which could help explain the superb positive effect of AE.

Photochemical hydrogen evolution on metal ion surface-grafted TiO2-particles prepared by sol/gel method without calcination

We report here a new class of co-catalysts for hydrogen evolution on TiO2 particles upon photo-irradiation. TiO2 particles prepared by sol/gel method was allowed to graft metal ion by a simple treatment with metal salts (Pt (IV), Rh (III), Cu (II), Fe(III), Al (III) ions) in water. The metal ion surface-grafted particles of TiO2(sol/gel) exhibit excellent photochemical hydrogen evolution compared to Pt (0) cluster loaded particles of TiO2(sol/gel) under the UV light irradiation of λ>290nm. XPS analysis shows that the valence states of the metal ions grafted on the TiO2 particles are the same with the parent metal ion salts and no metal (0) clusters were detected. DFT calculation of the simple model of metal ion/TiO2 indicated that an injected electron mostly localized on the metal ion sites, but not on Ti sites, which rationalizes the metal ion serve as the hydrogen evolution sites. Earth abundant metal ions, Cu (II), Fe (III), and Al (III) thus can provide new class of hydrogen evolution sites for artificial photosynthetic systems. To explore the possibility of utilizing semiconductor as an electron relay in the future system of molecular-catalyst-sensitized water splitting into hydrogen and hydrogen peroxide, the stability of hydrogen peroxide on various TiO2 surfaces was examined. Hydrogen peroxide was found to be pretty stable on Rh (III), Fe (III), and Al (III) ions surface-grafted TiO2, while Pt (IV) and Cu (II) ion grafted one similarly caused decomposition of hydrogen peroxide as Pt (0) cluster loaded TiO2 (Pt(0)/TiO2).

Controlling a possible outbreak of Candida auris infection: lessons learnt from multiple interventions

Multidrug-resistant Candida auris infection has been reported from five continents in recent years. The prevalence of C.auris invasive infection has been estimated at 5.3% for intensive-care-acquired candidaemia in India. The transmission of the organism between the patients and from environment to patients is rapid. To understand the intra-hospital dynamics of C.auris transmission and to determine the possible interventions to prevent its spread. Surveillance of intensive care units was carried out to assess patient colonization, environmental contamination and hand carriage of the yeast among healthcare workers. Interventions including chlorhexidine washing of patients and decontamination of environmental surfaces with stabilized hydrogen peroxide disinfectant (Ecoshield) were undertaken. We further evaluated the effectiveness of frequently used disinfectants in the hospital against C.auris on various inanimate surfaces, and its persistence on hospital fabrics. Three cases of C.auris bloodstream infection were detected over a period of three months. Many patients admitted at the same time, in the same area, were colonized by C.auris. Surveillance detected C.auris contamination of environmental surfaces and hands of healthcare workers. Interventions such as chlorhexidine washing and appropriate use of disinfectants could eradicate C.auris from patients and hospital environment. The frequently used disinfectants in our hospital and current hand hygiene practices were efficient against C.auris if proper contact time and procedures were followed. Evaluation of possible persistence of C.auris on dry fabrics showed that they can persist for up to seven days.