Results 291 to 300 of about 5,243,021 (356)
Some of the next articles are maybe not open access.
Tetrahedron, 1968
Abstract The effect of KOH fusion, pyrolysis, and hydriodic acid on acid boiled humic acid (ABHA) has been studied. As many of the products of the KOH fusion of ABHA are obtained similarly from the “polymers” of o - or p -benzoquinone or furfural, it is probable that the fusion products shed little, if any, light on the constitution of HA.
M.V. Cheshire +2 more
openaire +1 more source
Abstract The effect of KOH fusion, pyrolysis, and hydriodic acid on acid boiled humic acid (ABHA) has been studied. As many of the products of the KOH fusion of ABHA are obtained similarly from the “polymers” of o - or p -benzoquinone or furfural, it is probable that the fusion products shed little, if any, light on the constitution of HA.
M.V. Cheshire +2 more
openaire +1 more source
Desmutagenic effect of humic acid
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 1986In the present study, humic acid was not found to be mutagenic and did not inhibit spontaneous mutation. It did, however, inhibit the mutagenicities of benzo[a]pyrene and 3-aminoanthracene (+S9 mix), but not the mutagenicities of 4NQO, AF-2 and MNNG (-S9 mix).
T, Sato, Y, Ose, H, Nagase
openaire +2 more sources
Environmental Toxicology and Chemistry, 1991
Abstract Iodide binding by humic acid was studied. The reaction was dose, temperature and pH dependent. A maximum binding of 88% was reached with 2 mg humic acid in 0.15 M Tris buffer. The efficiency of iodide binding by the buffer becomes higher whenever the buffer is slightly alkaline.
Tien-Shang Huang, Fung-Jou Lu
openaire +1 more source
Abstract Iodide binding by humic acid was studied. The reaction was dose, temperature and pH dependent. A maximum binding of 88% was reached with 2 mg humic acid in 0.15 M Tris buffer. The efficiency of iodide binding by the buffer becomes higher whenever the buffer is slightly alkaline.
Tien-Shang Huang, Fung-Jou Lu
openaire +1 more source
Methylation of Humic Acid Fractions
Science, 1978A new three-step permethylation procedure for humic acid fractions has been developed. In the first step, carboxylic acid groups are methylated with diazomethane in dimethylformamide; in the second step, hydroxyl groups are methylated with methyl iodide and dimethyl sulfinyl carbanion in dimethylformamide; and in the third step, acidic groups ...
R L, Wershaw, D J, Pinckney
openaire +2 more sources
Americium Binding to Humic Acid
Environmental Science & Technology, 2001The binding of americium (Am) by peat humic acid (PHA) has been investigated at Am concentrations between 10(-1) and 10(-7) M at pH approximately 2.6 in the presence and absence of Cu as a competing ion. Cu-PHA binding was also investigated in order to derive independent binding constants for use in modeling the competitive binding studies.
Peters, Adam J. +2 more
openaire +2 more sources
2005
Humic acids are iodinated by elemental iodine and, if the iodine is present as iodide, by peroxidase-mediated reactions. It is demonstrated that iodination of humic acids leads to a product with a uniform distribution of iodine. It could not be unambiguously verified whether the enzymatically mediated iodination is a direct reaction between a ...
Jesper V. Christiansen, Lars Carlsen
openaire +1 more source
Humic acids are iodinated by elemental iodine and, if the iodine is present as iodide, by peroxidase-mediated reactions. It is demonstrated that iodination of humic acids leads to a product with a uniform distribution of iodine. It could not be unambiguously verified whether the enzymatically mediated iodination is a direct reaction between a ...
Jesper V. Christiansen, Lars Carlsen
openaire +1 more source
Electrophoretic aggregation of humic acid
Journal of Chromatography A, 2004Capillary electrophoresis (CE) has been used to characterize humic acid (HA) aggregation. It was found that when pumping HA solution through the capillary at a constant flow rate with no electric field, the number of spikes could be reduced by filtration of the solution. Applying high voltage (30 kV), the amount of spikes increased again.
Monika, Ubner +3 more
openaire +2 more sources
Humic acid: Inhibitor of plasmin
Science of The Total Environment, 1992Synthetic humic acid, well water humic acid and commercial humic acid (Aldrich) all have the ability to inhibit human plasmin activity. At a concentration of 20 micrograms/ml, all three species will result in 93%, 70% and 40% of residual plasmin activity, respectively. The components of humic acid, such as protocatechuic acid, resorcinol, vanillic acid
F J, Lu, Y S, Lee
openaire +2 more sources
Antiviral properties of humic acids
Experientia, 1972Es wird ein antiviraler Effekt von Ammoniumhumat gegenuber Coxsackiervirus A9 in FL-Zellkulturen nachgewiesen. Die antivirale Wirkung ist auf den Humatanteil des Molekuls zuruckzufuhren.
R, Klöcking, M, Sprössig
openaire +2 more sources
Adsorption of Humic Substances on Goethite: Comparison between Humic Acids and Fulvic Acids
Environmental Science & Technology, 2006The adsorption of humic acids (HA) to goethite (at pH 3-11) and the proton co-adsorption (at pH 4.0, 5.5, and 7.0) were measured, and the results were compared to those of fulvic acids (FA). Compared to FA, the adsorption of HA is stronger and more ionic strength dependent. The adsorption of both HA and FA decreases with increasing pH.
Weng, L.P. +3 more
openaire +2 more sources