Extraction of formic and acetic acids from aqueous solution by dynamic headspace-needle trap extraction

The equilibrium constant for the addition of sodium methoxide to methyl trifluoroacetate, in methanol as solvent, has been measured by 19F nmr, and is 7 M−1. From this was calculated an equilibrium constant, 2 × 10−4 M−1, for addition of methanol to the ester. The equilibrium constant for formation of methyl trifluoroacetate in aqueous solutions is 0.06 M−1. These results, with literature data, permit calculation of the free energies of formation in aqueous solution of orthotrifluoroacetic acid and its mono-, di-, and trimethyl esters. These in turn permit calculation of the standard free energy changes for addition of water and methanol to trifluoroacetic acid and its methyl ester. These combined with the analogous values for formic and acetic acids permit evaluation of ρ* values for these addition reactions. Linear plots are obtained if correction is made for steric effects, and the ρ* values are somewhat larger, 2.1–2.9, than was observed for the analogous carbonyl addition reactions.

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Biosorption of formic and acetic acids from aqueous solution using activated carbon from shea butter seed shells

Applied Water Science ◽

10.1007/s13201-016-0491-3 ◽

2016 ◽

Vol 7 (6) ◽

pp. 2727-2736

Author(s):

Folahan A. Adekola ◽

Ismaila A. Oba

Keyword(s):

Aqueous Solution ◽

Activated Carbon ◽

Shea Butter ◽

Acetic Acids

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Extraction Equilibria of Formic and Acetic Acids from Aqueous Solution by Phosphate-Containing Extractants

Journal of Chemical & Engineering Data ◽

10.1021/je010117i ◽

2001 ◽

Vol 46 (6) ◽

pp. 1472-1475 ◽

Cited By ~ 45

Author(s):

Weibin Cai ◽

Shenlin Zhu ◽

Xianglan Piao

Keyword(s):

Aqueous Solution ◽

Extraction Equilibria ◽

Acetic Acids

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CCXCIV.—Electrometric titration curves of dibasic acids. Part IV. Corrections for interionic effects and for solvent electrostriction. First and second dissociation constants of some n-paraffin αω-dicarboxylic acids, alkyl- and dialkyl-malonic acids, s-di- and -tetra-alkylsuccinic acids, β-alkyl-and ββ-dialkyl-glutaric acids, and cyclic 1 : 1-di-acetic acids. Remarks on the configurations and molecular dimensions of these acids in dilute aqueous solution

Journal of the Chemical Society (Resumed) ◽

10.1039/jr9310002153 ◽

1931 ◽

Vol 0 (0) ◽

pp. 2153-2169 ◽

Cited By ~ 28

Author(s):

Richard Gane ◽

Christopher Kelk Ingold

Keyword(s):

Aqueous Solution ◽

Dissociation Constants ◽

Dicarboxylic Acids ◽

Titration Curves ◽

Electrometric Titration ◽

Dilute Aqueous Solution ◽

Molecular Dimensions ◽

Acetic Acids

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Junction of the Epithelium and Lamina Propria of the Bovine Rumen Mucosa

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060350 ◽

1967 ◽

Vol 25 ◽

pp. 68-69

Author(s):

Al W. Stinson

Keyword(s):

Osmium Tetroxide ◽

Squamous Epithelium ◽

Short Chain Fatty Acids ◽

Chloride Ions ◽

Fermentation Products ◽

Ruminant Species ◽

Protective Shield ◽

Stratified Squamous Epithelium ◽

Lead Hydroxide ◽

Acetic Acids

The stratified squamous epithelium which lines the ruminal compartment of the bovine stomach performs at least three important functions. (1) The upper keratinized layer forms a protective shield against the rough, fibrous, constantly moving ingesta. (2) It is an organ of absorption since a number of substances are absorbed directly through the epithelium. These include short chain fatty acids, potassium, sodium and chloride ions, water, and many others. (3) The cells of the deeper layers metabolize butyric acid and to a lesser extent propionic and acetic acids which are the fermentation products of rumen digestion. Because of the functional characteristics, this epithelium is important in the digestive process of ruminant species which convert large quantities of rough, fibrous feed into energy.Tissue used in this study was obtained by biopsy through a rumen fistula from clinically healthy, yearling holstein steers. The animals had been fed a typical diet of hay and grain and the ruminal papillae were fully developed. The tissue was immediately immersed in 1% osmium tetroxide buffered to a pH of 7.4 and fixed for 2 hrs. The tissue blocks were embedded in Vestapol-W, sectioned with a Porter-Blum microtome with glass knives and stained with lead hydroxide. The sections were studied with an RCA EMU 3F electron microscope.

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