نتایج جستجو برای: butyl ammonium hydroxide
تعداد نتایج: 53246 فیلتر نتایج به سال:
Zinc hydroxide fluoride (Zn(OH)F) with novel flower-like morphology has been prepared via a microwave-assisted ionic liquid route. The flower-like Zn(OH)F particle has six petals and every petal is composed of lots of acicular nano-structure. Nanoporous ZnO is obtained by thermal decomposition of as-prepared Zn(OH)F in air, and the flower-like morphology is well retained. In the process of synt...
application of atoxigenic strains of aspergillus flavus to reduce aflatoxin levels is the most successful strategy applied in some agricultural crops. the role of ammonium hydroxide for preliminary screening of the competitiveness of atoxigenic a. flavus isolates to interfere with aflatoxin production by highly toxigenic isolates were evaluated. out of 270 a. flavus isolates, 17 were detected a...
The paper presents a study leading to a new acute toxicity test on embryonic and juvenile organisms of the great pond snail (Lymnaea stagnalis Linnaeus). Sulfuric acid, nitric acid, and ammonium hydroxide were used as waterborne toxicants in laboratory experiments. The exposure time was 24 h. Tests were conducted in 5–10 replications for each toxicant. The toxicity of the substances was classif...
A novel, conformationally preorganized nonnucleosidic universal solid support for oligonucleotide synthesis was developed. The solid support featured two chemically equivalent hydroxy groups locked in syn-periplanar orientation and orthogonally protected with 4,4'-dimethoxytrityl and acetyl groups. The solid support was extensively tested in the preparation of oligonucleotides and their phospho...
Ammonium hydroxide (NH4OH) is a chemical used in the manufacture of semiconductor devices, and must therefore be analyzed for trace metal impurities. The direct analysis of undiluted (20%) NH4OH using ICP-MS is challenging because its high vapor pressure causes plasma instability. However, dilution of the samples would degrade detection limits, so the ability to directly analyze 20% NH4OH is im...
This work presents a method of screening of alkanophenoxy carboxylic (2,4-D, 2,4,5-T, MCPA, MCPP) and phenolic (dinoterb, dinoseb, pentachlorophenol) herbicides in water. The successive steps of the method, i.e. liquid-liquid extraction with ethyl acetate and methyl-tert-butyl ether and solid phase extraction using C18-modified silica gel and styrenedivinylbenzene copolymer-packed cartridges as...
The application of calorimetric principles to the determination of phosphorus is especially desirable in view of the long drawn out and laborious gravimetric method now customarily employed. The accuracy of calorimetric methods, the ease with which most calorimetric procedures are carried on and their employment where only small amounts of material are available for analysis would make a reliab...
Cis-polybutadiene was functionalized using in–situ generated DMD as oxidant and tetra-n-butyl ammonium bromide as phase transfer catalyst (PTC). The epoxidation process was investigated by 1HNMR spectroscopy. 1HNMR spectrum analysis of products confirms the absence of ring opening side products in epoxidation reaction. Various factors such as reaction temperature, reaction time and the concentr...
In this study, to determine the pKa values of 2-ethoxy-6-(3-substitue-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl-azomethine)-phenyl benzoates (1-9) were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl acetone and N,N-dimethylformamide (DMF), graphs drawn for all cases. addition, effects molecular structure upon acidit...
Although cleaners represent a significant part of the working population worldwide, they remain a relatively understudied occupational group. Epidemiological studies have shown an association between cleaning work and asthma, but the risk factors are uncertain. Cleaning workers are exposed to a large variety of cleaning products containing both irritants and sensitizers, as well as to common in...
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