scholarly journals Ring transformation of heterocycles by oxidizing agents. A 14C-study of the conversion of quinolines into indoles by hydrogen peroxide.

1975 ◽  
Vol 23 (11) ◽  
pp. 2682-2685 ◽  
Author(s):  
H.C.van der PLAS ◽  
D.J. BUURMAN
Keyword(s):  
Hydrogen Peroxide ◽  
Ring Transformation ◽  
Oxidizing Agents

Hydrogen Peroxide and Di(hydroperoxy)propane Adducts of Phosphine Oxides as Stoichiometric and Soluble Oxidizing Agents

2015 ◽  
Vol 127 (45) ◽  
pp. 13539-13543 ◽  
Author(s):  
Shin Hye Ahn ◽  
Kyle J. Cluff ◽  
Nattamai Bhuvanesh ◽  
Janet Blümel
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphine Oxides ◽  
Oxidizing Agents

scholarly journals Various Digestion Protocols Within Microplastic Sample Processing—Evaluating the Resistance of Different Synthetic Polymers and the Efficiency of Biogenic Organic Matter Destruction

2020 ◽  
Vol 8 ◽  
Author(s):  
Felix Pfeiffer ◽  
Elke Kerstin Fischer
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Matter ◽  
Polyethylene Terephthalate ◽  
Sodium Hypochlorite ◽  
Temperature Increase ◽  
Synthetic Polymers ◽  
Special Focus ◽  
Hard Tissue ◽  
Oxidizing Agents ◽  
Project Objectives

The digestion of biogenic organic matter is an essential step of sample preparation within microplastic analyses. Organic residues hamper the separation of polymer particles especially within density separation or polymer identification via spectroscopic and staining methods. Therefore, a concise literature survey has been undertaken to identify the most commonly applied digestion protocols with a special focus on water and sediments samples. The selected protocols comprise different solutions, concentrations, and reaction temperatures. Within this study we tested acids (nitric acid and hydrochloric acid), bases (sodium hydroxide and potassium hydroxide), and oxidizing agents [hydrogen peroxide, sodium hypochlorite and Fenton's reagent (hydrogen peroxide 30% in combination with iron(II)sulfate 0.27%)] at different concentrations, temperature levels, and reaction times on their efficiency of biogenic organic matter destruction and the resistance of different synthetic polymers against the applied digestion protocols. Tests were carried out in three parallels on organic material (soft tissue—leaves, hard tissue—branches, and calcareous material—shells) and six polymers (low-density polyethylene, high-density polyethylene, polypropylene, polyamide, polystyrene, and polyethylene terephthalate) in two size categories. Before and after the application of different digestion protocols, the material was weighed in order to determine the degree of digestion efficiency and polymer resistance, respectively. The efficiency of organic matter destruction is highly variable. Calcareous shells showed no to very low reaction to oxidizing agents and bases, but were efficiently dissolved with both tested acids at all concentrations and at all temperatures. Soft and hard tissue were most efficiently destroyed by sodium hypochlorite. However, the other reagents can also have good effects, especially by increasing the temperature to 40–50°C. The additional temperature increase to 60–70°C showed a further but less effective improvement, compared to the initial temperature increase. The resistance of tested polymer types can be rated as good except for polyamide and polyethylene terephthalate. Increasing the concentrations and temperatures, however, results in accelerated degradation of all polymers. This is most evident for polyamide and polyethylene terephthalate, which show losses in weight between 15 and 100% when the digestion temperature is increased. This effect is most pronounced for polyamide in the presence of acids and for polyethylene terephthalate digested with bases. As a concluding recommendation the selection of the appropriate digestion method should be specifically tested within initial pre-tests to account for the specific composition of the sample matrix and the project objectives.

scholarly journals Ring Transformation Mediated by Lewis Acids and Oxidizing Agents. Synthesis of 2-Methoxy-1H-imidazole from 5-Aminopyrimidin-4(3H)-one.

1993 ◽  
Vol 41 (3) ◽  
pp. 608-610 ◽  
Author(s):  
Izumi MATSUURA ◽  
Taisei UEDA ◽  
Nobutoshi MURAKAMI ◽  
Shin-ichi NAGAI ◽  
Jinsaku SAKAKIBARA
Keyword(s):  
Lewis Acids ◽  
Ring Transformation ◽  
Oxidizing Agents

scholarly journals Pretreating Epoxy Thin Sections With Sodium Periodate Prior To Immunostaining

1997 ◽  
Vol 5 (6) ◽  
pp. 24-25 ◽  
Author(s):  
Hildegard H. Crowley
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Layer ◽  
Electron Density ◽  
Sodium Methoxide ◽  
Sodium Periodate ◽  
Thin Sections ◽  
Oxidizing Agents ◽  
Antigenic Sites

Pretreatment of epoxy thin sections with strong oxidizing agents such as hydrogen peroxide, sodium methoxide, and sodium m-metaperiodate facilities the location of antigens with immunostaining procedures. Etching, or pretreatment, of sections unmasks antigenic sites on glutaraldehyde fixed and postosmicated tissue, partially removes osmium bonds, temporarily decreases the hydrophobicity of the epoxy surface layer of the section, reduces the electron density of the tissue and increases resistance to heavy rnetai poststaining.

Seed Germination in Ruzizi Grass (Brachaaria ruziziensis Germain & Evrard)

1976 ◽  
Vol 24 (4) ◽  
pp. 437 ◽  
Author(s):  
C Renard ◽  
P Capelle
Keyword(s):  
Hydrogen Peroxide ◽  
Seed Germination ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Oxidizing Agents ◽  
Brachiaria Ruziziensis

Sowing is the most common way of establishing Brachiaria ruziziensis in pastures, but seed germi- nation is poor as a result of dormancy. The mechanism of dormancy is clearly located in the hull, for removing the hull or cutting at the base of the spikelet stimulates germination. No leachable inhibitor seems to be the cause of dormancy. However, the action of oxidizing agents such as hydrogen peroxide and the measurement of oxygen uptake by full or empty spikelets suggest that a restriction of gas exchange by the hull is responsible.

Nanorods of Tellurium: Synthesis and Self-Assembly

2006 ◽  
Vol 6 (3) ◽  
pp. 719-725 ◽  
Author(s):  
Sudip K. Batabyal ◽  
C. Basu ◽  
A. R. Das ◽  
G. S. Sanyal
Keyword(s):  
Hydrogen Peroxide ◽  
Self Assembly ◽  
Solution Phase ◽  
Simple Solution ◽  
Experimental Conditions ◽  
Oxidizing Agents ◽  
Phase Approach ◽  
Size And Shape

A simple solution phase approach is described to prepare tellurium nanorods which undergo morphological modifications to yield different microstructures under varied experimental conditions. The morphology of the prepared products is drastically altered in presence of a few oxidizing agents such as sodium oxychloride (NaOCl), hydrogen peroxide (H2O2) etc. The effects of poly (sodium 4-styrene sulphonate) (PSS) and Isooctyl phenoxy poly oxyethanol (TritonX-100) on the size and shape of the products in presence of air/NaOCl have also been monitored.

scholarly journals Whitening of a Non-Vital Tooth with Walking Bleach Technique: A Case Series

2021 ◽  
Vol 5 (2) ◽  
pp. CR1-CR5
Author(s):  
Deepika ◽  
Muhammad Mutiur Rahman ◽  
Ajay Kumar Nagpal
Keyword(s):  
Hydrogen Peroxide ◽  
Case Series ◽  
Sodium Perborate ◽  
Endodontically Treated Teeth ◽  
Efficient Treatment ◽  
Chemical Substances ◽  
Significant Aspect ◽  
Oxidizing Agents ◽  
Anterior Teeth ◽  
Tooth Discoloration

A significant aspect of cosmetic dentistry is the treatment of tooth discoloration. Discoloration of non-vital anterior teeth can cause significant esthetic concern and requires efficient treatment. Discoloration of teeth can be extrinsic or intrinsic or a combination of both based on etiology, appearance, localization, and severity. Walking bleach involves the use of chemical substances like sodium perborate or hydrogen peroxide which in contact with the tooth release oxidizing agents that diffuse through the enamel and dentin and oxidize the pigments responsible for discoloration. This article aims at presenting a case series on the walking bleach method performed on discolored endodontically treated teeth associated with superior esthetic outcomes.

scholarly journals Mode of action of hydrogen peroxide and other oxidizing agents: differences between liquid and gas forms

2010 ◽  
Vol 65 (10) ◽  
pp. 2108-2115 ◽  
Author(s):  
M. Finnegan ◽  
E. Linley ◽  
S. P. Denyer ◽  
G. McDonnell ◽  
C. Simons ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Mode Of Action ◽  
Oxidizing Agents

ChemInform Abstract: Ring Transformation Mediated by Lewis Acids and Oxidizing Agents. Synthesis of 2-Methoxy-1H-imidazole from 5-Aminopyrimidin-4(3H)-one.

ChemInform ◽  
2010 ◽  
Vol 25 (7) ◽  
pp. no-no
Author(s):  
I. MATSUURA ◽  
T. UEDA ◽  
N. MURAKAMI ◽  
S. NAGAI ◽  
J. SAKAKIBARA
Keyword(s):  
Lewis Acids ◽  
Ring Transformation ◽  
Oxidizing Agents
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