Organic acids from salts

Dilute sodium hydroxide solution (and also sodium carbonate solution and sodium bicarbonate solution) can be employed for the removal of an organic acid from its solution in an organic solvent, or for the removal of acidic impurities present in a water-insoluble solid or liquid. The extraction is based upon the fact that the sodium salt of the acid is soluble in water or in dilute alkali, but is insoluble in the organic solvent. Similarly, a sparingly soluble phenol, e.g., p-naphthol, CioH,.OH, may be removed from its solution in an organic solvent by treatment with sodium hydroxide solution. 

Salts of Organic Acids. Calcium salts of organic acids may be prepared by reaction of the carbonate hydroxide and the organic acid (9). Calcium lactate [814-80-2] is an iatermediate ia the purification of lactic acid from fermentation of molasses. Calcium soaps, soaps of fatty acids, ate soluble ia hydrocarbons, and are useful as waterproofing agents and constituents of greases (9). 

Water Splitting A modified electrodi ysis arrangement is used as a means of regenerating an acid and a base from a corresponding salt. For instance, NaCl may be used to produce NaOH and HCl. Water sphtting is a viable alternative to disposal where a salt is produced by neutralization of an acid or base. Other potential applications include the recovery of organic acids from their salts and the treating of effluents from stack gas scrubbers. The new component required is a bipolar membrane, a membrane that sphts water into H and OH". At its simplest, a bipolar membrane may be prepared by... 

This extraction is designed to remove the organic acids from the inorganic salts. The extraction may also be effected by continuous extraction.4... 

General Methods of isolating organic acids from their salts may here be noted. 

Concentration Edible table salt production from seawater Salts of organic acids from exhausted fermentation media Amino acids from protein hydrolysates... 

The incomplete comprehension of mass transfer mechanisms in ED membrane systems is in all probability responsible for the difficult design of industrial plants and for their limited diffusion. For instance, in the food biotechnology sector ED applications are still in their infancy since quite a limited number of the novel processes studied so far in laboratory- and pilot-scales and reviewed here have been converted into industrial realities yet, except for the recovery of the sodium salt of unspecified organic acid from clarified fermentation broths, as well as amino and organic acids (Gillery et al., 2002). 

Takatsuji, W., Nakauchi, M., and Yoshida, H. 1999. Removal of salt and organic acids from solution used to season salted Japanese apricots (Ume) by electrodialysis, precipitation and adsorption. J. Biosci. Bioeng. 88, 348-351. 

Bartell and Fu1 find a similar hydrolytic adsorption of organic acids, from their salts, on silica. 

REMOVAL OF SALT AND ORGANIC ACIDS FROM SOLUTION USED TO SEASON SALTED JAPANESE APRICOTS VME) BY COMBINING ELECTRODIALYSIS AND ADSORPTION... 

Chlorhexidine salts of low aqueous solubility are formed and may precipitate from chlorhexidine solutions of concentration greater than 0.05% w/v, when in the presence of inorganic acids, certain organic acids, and salts (e.g. benzoates, bicarbonates, borates, carbonates, chlorides, citrates, iodides, nitrates, phosphates, and sulfates). At chlorhexidine concentrations below 0.01% w/v precipitation is less likely to occur. 

Certain organic samples such as lower molecular weight alcohols, polyalcohols, organic acids, organometallic salts, amines and esters in either aliphatic or aromatic form can be analysed directly or after dilution in a suitable ICP-AES compatible solvent. These samples can be analysed for formulated or contaminated metals against a calibration curve prepared from a certified stock standard in the same solvent. Organic samples with varying viscosities, particularly for trace metals content, may be... 

Catalysts having a very acid nature such as metaphosphoric acid, arsenious acid, boric acid, or salts of these acids have been proposed. The addition of copper as such or as the formate serves to promote the reaction.190 Reaction chambers extremely resistant to corrosion must be tised. Catalysts such as zinc arsenite. or zinc or chromium metaphosphatc having a highly acidic nature are claimed to be effective in the formation of organic acids from carbon monoxide and alcohols at temperatures of about 300° C. and a pressure of 200 atmospheres. Even with such acidic catalysts considerable quantities of esters are stated to be formed.101... 

Shimshick, E. J., Removal of organic acids from dilute aqueous solutions of salts of organic acids by supercridcal fluids, U.S. 4,250,331 (Feb. 10,1981). 

Diffusion dialysis through anion exchange membranes is used today on large scale to recover acids from pickling solution. Donnan dialysis is used for water softening or for recovering organic acids from their salts. 

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