Results 251 to 260 of about 591,302 (312)
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Chemistry – A European Journal, 2012
AbstractThe capability of a gaseous Brønsted acid HB to deliver protons to a base is usually described by the gas‐phase acidity (GA) value of the acid. However, GA values are standard Gibbs energy differences and refer to individual gas pressures of 1 bar for acid HB, base B−, and proton H+.
Himmel, Daniel +3 more
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AbstractThe capability of a gaseous Brønsted acid HB to deliver protons to a base is usually described by the gas‐phase acidity (GA) value of the acid. However, GA values are standard Gibbs energy differences and refer to individual gas pressures of 1 bar for acid HB, base B−, and proton H+.
Himmel, Daniel +3 more
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Gas-Phase Acidities of Phosphorylated Amino Acids
The Journal of Physical Chemistry B, 2015Gas-phase acidities and heats of formation have been predicted at the G3(MP2)/SCRF-COSMO level of theory for 10 phosphorylated amino acids and their corresponding amides, including phospho-serine (pSer), -threonine (pThr), and -tyrosine (pTyr), providing the first reliable set of these values.
Michele L, Stover +4 more
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Gas chromatography of fatty acids
Journal of Chromatography A, 1992Lipids in foods contain a wide variety of fatty acids differing in chain length, degree of unsaturation, position and configuration of double bonds and the presence of special functional groups. Modern capillary gas chromatography offers excellent separation of fatty acids.
N C, Shantha, G E, Napolitano
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Gas chromatography of amino acids
Journal of Chromatography A, 1975This review summarizes all papers that have appeared on the gas chromatography of amino acids (including the iodoamino acids) and their enantiomers in the period 1956-mid-1974. It has been found that the methods used for analysis of amino acids can be divided into three classes: (1) degradative procedures and techniques for converting the amino acid ...
Petr Hušek, Karel Macek
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Journal of Mass Spectrometry, 1998
The kinetic method was applied to the estimation of the gas-phase acidity of urea by generating proton-bound dimeric anions comprised of urea and various reference compounds using negative ion desorption chemical ionization and examining their dissociation upon collision in a triple quadrupole mass spectrometer.
Shuguang Ma, Feng Wang, R. Graham Cooks
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The kinetic method was applied to the estimation of the gas-phase acidity of urea by generating proton-bound dimeric anions comprised of urea and various reference compounds using negative ion desorption chemical ionization and examining their dissociation upon collision in a triple quadrupole mass spectrometer.
Shuguang Ma, Feng Wang, R. Graham Cooks
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Gas chromatography of bile acids
Journal of Chromatography B: Biomedical Sciences and Applications, 1999Bile acids, the end products of cholesterol metabolism in the liver, are of vital importance in the tissue distribution of cholesterol. Abnormalities in cholesterol biosynthesis or metabolism are often reflected in the proportions, concentrations and conjugation of bile acids in various tissues and determination of bile acids in these tissues is ...
A K, Batta, G, Salen
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Gas-phase acidities of thiocarboxylic acids
International Journal of Mass Spectrometry, 2007Abstract The gas-phase acidity of thioacetic acid, determined using ion–molecule equilibrium reactions, was found to be ΔGacid = 329.0 ± 1.5 kcal mol−1. The gas-phase acidity of thiobenzoic acid was determined by ion–molecule bracketting reactions to be ΔGacid = 323 ± 5 kcal mol−1. Gas-phase acidities of these compounds, as well as of thioformic acid,
Nicole Eyet, Veronica M. Bierbaum
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Gas sensitivity of amino acids monolayers
2008 IEEE Sensors, 2008In this work amino acids are used as a combinatorial library for gas and mixtures identification. Amino acids are characterized by the presence of different functional units that may act as bonding sites for volatile compounds. To demonstrate this assumption, monolayers of four amino acids (Tyrosine, Phenylalanine, Lysine and Histidine) have been ...
Martinelli +16 more
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