Chemistry of Fulvic Acid, a Soil Humic Fraction, and its Relation to Lignin

1971 ◽  
Vol 49 (7) ◽  
pp. 1053-1063 ◽  
Author(s):  
G. Ogner ◽  
M. Schnitzer
Keyword(s):  
Gas Chromatography ◽  
Hydrogen Bonding ◽  
Fulvic Acid ◽  
Water Soluble ◽  
Chromatographic Retention ◽  
Biological Oxidation ◽  
Polycarboxylic Acids ◽  
Preparative Gas Chromatography ◽  
Humic Fraction ◽  
Benzenecarboxylic Acids

Fulvic acid, a water-soluble soil humic fraction, was extracted from a Podzol soil and exhaustively methylated so as to make it soluble in benzene. The resulting material was separated repeatedly by column, thin layer, and preparative gas chromatography until relatively pure components were obtained. The latter were then identified by comparing their mass and micro-i.r. spectra and their gas chromatographic retention times with those of standards of known structures.Twenty-one phenolic and benzene-carboxylic acids were identified as methyl ethers and esters. In addition, a number of polymethoxy-benzene polycarboxylic acids of as yet unknown identity were isolated.A number of the compounds isolated have been reported to arise from the alkaline KMnO4 oxidation of lignin. Since we did not oxidize the fulvic acid in the laboratory, it is likely that it originated from products resulting from the chemical and/or biological oxidation of lignin in the soil. Methylation of the fulvic acid was necessary to make the compounds extractable by organic solvents. Since methylation reduces hydrogen-bonding in the fulvic acid, it is suggested that in fulvic acid phenolic and benzenecarboxylic acids are joined by hydrogen-bonds to form a polymeric structure of yet unknown conformation. Any weakening of hydrogen-bonding will lead to a break-up of this structure.

Further Investigations on the Chemistry of Fulvic Acid, a Soil Humic Fraction

1971 ◽  
Vol 49 (13) ◽  
pp. 2302-2309 ◽  
Author(s):  
S. U. Khan ◽  
M. Schnitzer
Keyword(s):  
Fatty Acids ◽  
Hydrogen Bonds ◽  
Fulvic Acid ◽  
Phenolic Acids ◽  
Complex Structures ◽  
Isolation And Identification ◽  
Fractionation Scheme ◽  
Humic Fraction ◽  
Benzenecarboxylic Acids

The fractionation scheme described in this and in an earlier paper resulted in the isolation and identification of about 2.0 g of pure components from 100 g of fulvic acid. About 28% of these compounds were phenolic acids, 19% benzenecarboxylic acids, 13% alkanes and fatty acids, and 40% dialkyl phthalates. The isolation of appreciable amounts of dialkyl phthalates was somewhat surprising but their presence was shown not be an artifact. The KMnO4 oxidation of the same fractions increased the yields of methylated phenolic and benzenecarboxylic acids by between 3 and 11 times.Following KMnO4 oxidation of methylated but unfractioned fulvic acid, the yield of phenolic and benzenecarboxylic acids increased substantially. The increased yields, after oxidation, of the same compounds as those that were separated without oxidation indicate that either these compounds originated from more complex structures or that they came from a structure of the type proposed earlier, which consists of phenolic and benzenecarboxylic acids joined by hydrogen-bonds, on which alkanes, fatty acids, and dialkyl phthalates are adsorbed.

scholarly journals Pesticidal residue analysis and phytochemical screening in leaves and roots of Barleria prionitis Linn.

2018 ◽  
Vol 8 (5) ◽  
pp. 455-459
Author(s):  
Reema Dheer ◽  
Surendra Swarnkar
Keyword(s):  
Gas Chromatography ◽  
Organochlorine Pesticides ◽  
Pesticide Residues ◽  
Capillary Column ◽  
Residue Analysis ◽  
Extraction Procedure ◽  
Water Soluble ◽  
Phytochemical Screening ◽  
Plant Materials ◽  
Leaves And Roots

In the present study emphasize on phytochemical screening in leaves and roots of Barleria prionitis Linn. The extract of plant materials total ash content, extractive value, water soluble ash, and loss on drying values were identified. Medicinal plant materials are liable to contain pesticide residues, which accumulate from agriculture practices, such as spraying, treatment of soils during cultivation and administration of fumigants during storage. It is therefore recommended that every sample of medicinal plants used for such type of studies should be analyzed for the pesticidal residues. Therefore in the present study parts of the herb used for their antidiabetic potential were analyzed for organochlorine pesticides, which are persistent and remain in the food chain for longer periods. The samples of leaf and root of Barleria prionitis were ground coarsely and then preceded for the extraction procedure. The sample of extracts were analysed for residues of organochlorine pesticides by Gas Chromatography (GC). Analysis were carried out on a Schimadzu Model 2010 Gas Chromatograph (GC) equipped with 63 NI electron capture detector (ECD) and a capillary column HP ultra 2. The instrument was supported by Lab Solution software. The pesticide residues detected in them in the GC were within the limits. For phytochemical screening, the ethanolic and hydroalcoholic extracts obtained were prepared and subjected to various qualitative tests in order to reveal the presence or absence of common phytopharmaceuticals by using standard tests. Keywords: Phytochemical screening, Pesticidal residues, Barleria prionitis Gas Chromatography, Ash value, extractive value.

Automated Preparative Gas Chromatography With Retention Time Updating

1984 ◽  
Vol 13 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Vanadah E. Burton ◽  
Toni R. Orr ◽  
Ann M. Brearly ◽  
Mary A. Kaiser
Keyword(s):  
Gas Chromatography ◽  
Retention Time ◽  
Preparative Gas Chromatography

scholarly journals Molecular Distributions of Soluble Oxidation Products from Coals Characterized by Mass Spectrometers

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xing Fan ◽  
Fei Wang
Keyword(s):  
Mass Spectrometry ◽  
Direct Analysis ◽  
Water Soluble ◽  
Oxidation Products ◽  
Gas Chromatography Mass Spectrometry ◽  
Mass Spectrometers ◽  
Polycarboxylic Acids ◽  
Alkanoic Acids ◽  
Carboxylic Groups ◽  
Soluble Species

Oxidation of three coals with rank from lignite to anthracite in NaOCl aqueous solution was investigated in this study. The oxidation products were characterized by using gas chromatography/mass spectrometry and direct analysis in real-time mass spectrometry. The results showed that most of organic compounds in coals were converted into water-soluble species under mild conditions, even the anthracite. Benzene polycarboxylic acids (BPCAs) and chloro-substituted alkanoic acids (CSAAs) were major products from the reactions. The products from lower rank coals consist of considerable CSAAs and most products from high rank coals are BPCAs. As coal rank increases, the yield of BPCAs with more carboxylic groups increases.

Molecular Recognition and Photoprotection of Riboflavin in Water by a Biomimetic Host

2021 ◽  
Author(s):  
Hong Zhang ◽  
Li-Li Wang ◽  
Xin-Yu Pang ◽  
Liu-Pan Yang ◽  
Wei Jiang
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Recognition ◽  
Hydrophobic Effect ◽  
Water Soluble ◽  
Side Walls

A water-soluble tetralactam macrocycle with 2,6-diethoxynaphthalene group as side walls is able to strongly bind riboflavin (Ka >107 M−1) in water through hydrogen bonding and the hydrophobic effect. The encapsulated...

Sign in / Sign up

Export Citation Format

Share Document