Organic acids levels

Organic acid Level Diet Crude protein Gross energy... 

Free amino acid and organic acid levels in Narezushi... 

Nemcova, R., Bomba, A., Gancarcikova, S., et al. (2007) Effects of the administration of lactobacilli, maltodextrins and fructooligosaccharides upon the adhesion of E. coli 08 K88 to the intestinal mucosa and organic acid levels in the gut contents of piglets. Vet Res Communic 31, 791-800. 

There are occasions where the mud pH must be lowered such as after drilling fresh cement or overtreatment by one of the alkaline materials discussed. Organic acids that have been used for this purpose include acetic acid [64-19-7], citric acid [77-92-9], and oxaHc acid [144-62-7]. These materials are used infrequently. Inorganic additives used to lower pH levels include sodium bicarbonate [144-55-8] and sodium acid pyrophosphate [7758-16-9] (SAPP). Of the two, sodium bicarbonate is used the most by far. 

A variety of shale-protective muds are available which contain high levels of potassium ions (10). The reaction of potassium ions with clay, well known to soil scientists, results in potassium fixation and formation of a less water-sensitive clay. Potassium chloride, potassium hydroxide, potassium carbonate [584-08-7] (99), tetrapotassium pyrophosphate [7320-34-5] (100), and possibly the potassium salts of organic acids, such as potassium acetate [127-08-2] (101) and formate, have all been used as the potassium source. Potassium chloride is generally preferred because of its low cost and availabihty. 

Organic acids, including carbon dioxide, lower the wort pH during fermentation. The principal acids formed are lactic, pymvic citric, malic, and acetic acids, at concentrations ranging from 100—200 ppm. The main sulfur compounds formed during fermentation and thek perception thresholds are as follows H2S (5—10 ppb) ethanethiol (5—10 ppb) dimethyl sulfoxide (35—60 ppb) and diethyl sulfide (3—30 ppb). At low levels, these may have a deskable flavor effect at higher levels they are extremely undeskable. Sulfur dioxide also forms during fermentation, at concentrations of 5—50 ppm its presence can be tasted at levels above 50 ppm. 

Gas turbine fuels can contain natural surfactants if the cmde fraction is high in organic acids, eg, naphthenic (cycloparaffinic) acids of 200—400 mol wt. These acids readily form salts that are water-soluble and surface-active. Older treating processes for sulfur removal can leave sulfonate residues which are even more powerful surfactants. Refineries have installed processes for surfactant removal. Clay beds to adsorb these trace materials are widely used, and salt towers to reduce water levels also remove water-soluble surfactants. In the field, clay filters designed as cartridges mounted in vertical vessels are also used extensively to remove surfactants picked up in fuel pipelines, in contaminated tankers, or in barges. 

A high performance Hquid chromotography (hplc) method to determine citric acid and other organic acids has been developed (46). The method is an isocratic system using sulfuric acid to elute organic acids onto a specific hplc column. The method is sensitive for citric acid down to ppm levels and is capable of quantifying citric acid in clear aqueous systems. 

If continuous addition of solids is not possible, additions should be made at as short intervals as possible. Alkahnity levels are normally maintained at about 3000 to 5000 mg/L to keep the pH in the range 6.5-7.5 as a buffer against variable organic-acid production with vaiy-ing organic loads. Proteins will produce an adequate buffer, but carbohydrates wall require the addition of alkalinity to provide a sufficient buffer. Sodium bicarbonate should be used to supply the buffer. 

Naphthenic acid is a collective name for organic acids present in some but not all crude oils. In addition to true naphthenic acids (naphthenic carboxylic acids represented by the formula X-COOH in which X is a cycloparaffin radical), the total acidity of a crude may include various amounts of other organic acids and sometimes mineral acids. Thus the total neutralization number of a stock, which is a measure of its total acidity, includes (but does not necessaiily represent) the level of naphthenic acids present. The neutralization number is the number of milligrams of potassium hydroxide required to neutralize one gram of stock as determined by titration using phenolphthalein as an indicator, or as determined by potentiometric titration. It may be as high as 10 mg KOH/gr. for some crudes. The neutralization number does not usually become important as a corrosion factor, however, unless it is at least 0.5 mg KOH/gm. 

The stripping of tantalum and niobium from the organic phase into aqueous media occurs in solutions with low acidity levels, leading to the formation of TaF 2 and NbOFs2, which have a lower charge and weaker Lewis acidity. 

OS 31] [R 16c] ]P 23] The levels of dinitrobenzene, dinitrophenol and picric acid in the organic phase during benzene nitration in a micro reactor were monitored [31]. Picric acid levels were no higher than 100 ppm for all experiments conducted. Dinitrobenzene was the largest impurity fraction. A study revealed contents < 1000 ppm up to 34 mass-% on increasing the sulfuric acid content from 70 to 85%. 

Figure 9 Proposed role of organic acid metabolism (citrate) in genotypical differences of rice in adaptation to high levels of soil bicarbonate tmd low Zn availability. (Adapted t rora Ref. 233.)...

These data strongly suggest that siderophore production by root-colonizing microorganisms is induced only at a level neeessary to supplement that which is not provided by phytosiderophores and organic acids released during the plant iron stress response. Thus, the plant iron stress response may control iron availability to microorganisms in the rhizosphere. 

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