نتایج جستجو برای: acidic solvents

تعداد نتایج: 78820  

Journal: :Clinical chemistry 1986
T Annesley K Matz L Balogh L Clayton D Giacherio

This liquid-chromatographic assay requires 0.2 to 0.5 mL of whole blood, avoids the use of diethyl ether, and consumes only 10 to 20% of the solvents used in prior methods. Sample preparation involves an acidic extraction with methyl-t-butyl ether, performed in a 13 X 100 mm disposable glass tube, then a short second extraction of the organic phase with sodium hydroxide. After evaporation of th...

Journal: :IET nanobiotechnology 2016
Sania Naz Naveed Ahmad Javeed Akhtar Nasir Mehmood Ahmad Attarad Ali Muhammad Zia

Citrus fruit processing industries produce a vast quantity of waste materials as peel and pulp that are not handled properly. In present study, waste generated from citrus has been used for extraction of cellulose and nanocellulose. The aggregated cellulose, derived after alkaline treatment, was acid hydrolysed; resulted in reduction of the size of cellulose fibre. The cellulose showed amorphou...

Journal: :The Onderstepoort journal of veterinary research 1994
C O Miles A L Wilkins G L Erasmus T S Kellerman J A Coetzer

Geeldikkop was induced in a sheep by oral administration of crude saponins from Tribulus terrestris. Centrifugation of the bile from this sheep gave a pale green sediment of crystalloid material which was insoluble in common organic solvents, but soluble in acetic acid. Analysis of the crystalloid material by 1H and 13C NMR, EDXA, TLC, LSIMS, and by acidic hydrolysis followed by TLC and GC-MS, ...

2017
Eno Paenurk Karl Kaupmees Daniel Himmel Agnes Kütt Ivari Kaljurand Ilmar A. Koppel Ingo Krossing Ivo Leito

The most comprehensive solvent acidity scale spanning 28 orders of magnitude of acidity was measured in the low-polarity solvent 1,2-dichloroethane (DCE). Its experimental core is linked to the unified acidity scale (pHabs) in an unprecedented and generalized approach only based on experimental values. This enables future measurements of acid strengths and acidity adjustments in low polarity so...

Journal: :Journal of the American Chemical Society 2009
Zheng Lu Carolyn B Knobler Hiroyasu Furukawa Bo Wang Guannan Liu Omar M Yaghi

Two imidazolate-metal based rhombic dodecahedra (termed MOP-100 and MOP-101) were designed and prepared from [(NH(3))(4)Pd(NO(3))(2)] and hydrogen tetrakis(1-imidazolyl)borate or hydrogen tetrakis(4-methyl-1-imidazolyl)borate in a concentrated ammonium hydroxide solution at 85 degrees C. Both rhombic dodecahedra show unusual chemical stability in acidic and basic solutions as well as common org...

Journal: :Beilstein Journal of Organic Chemistry 2006
Babak Kaboudin Fatemeh Farjadian

Reactions of O,O'-dialkyl thiophosphoric acids with alkyl halides, in the presence of a base, provide a direct synthetic route to phosphorothioates via O,O'-dialkyl thiophosphate anion formation. Studies on the reaction of ambident nucleophile ammonium O,O'-diethyl thiophosphate with benzyl halides and tosylate in different solvents show that only S-alkylation is obtained. Reaction of this ambi...

2009
Ari L. Horvath

Hair is composed of proteins, lipids, water, and small amounts of trace elements. All proteins in animal and human bodies are built from permutations of amino acid molecules in a polypeptide string. The polypeptide chains of protein keratin are organized into filaments in hair cells. Hair is one of the most difficult proteins to digest or solubilize. Among the most common dissolving procedures ...

2003
Jan Åke Jönsson Lennart Mathiasson Luke Chimuka Ewa Cukrowska

The techniques of membrane extraction permit the application of classical liquid-liquid extraction (LLE) chemistry to instrumental and automated operation. Various shortcomings of LLE are overcome by membrane extraction techniques as they use none or very little organic solvents, high enrichment factors can be obtained and there are no problems with emulsions. A three phase SLM system (aq/org/a...

2011
David Cheneler James Bowen Stephen D. Evans Marcin Górzny Michael J. Adams

The use of plasma-polymerised fluoropolymer (CFxOy) thin films in the manufacture of microelectromechanical systems (MEMS) devices is well-established, being employed in the passivation step of the deep reactive ion etching (DRIE) process, for example. This paper presents an investigation of the effect of exposure to organic and aqueous liquid media on plasma-polymerised CFxOy thin films. Atomi...

2016
Shusei Kanie Toshio Nishikawa Makoto Ojika Yuichi Oba

Firefly luciferin, the substrate for the bioluminescence reaction of luminous beetles, possesses a benzothiazole ring, which is rare in nature. Here, we demonstrate a novel one-pot reaction to give firefly luciferin in a neutral buffer from p-benzoquinone and cysteine without any synthetic reagents or enzymes. The formation of firefly luciferin was low in yield in various neutral buffers, where...

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