Organic acids general applications

McGarry, S.F. and Baker, A., (2000). Organic acid fluorescence Applications to speleo-them palaeoclimate reconstruction. Qmt. Sci. Rev., 19, 1087-1101 McKnight, D.M., Boyer, E.W., Westerhoff, P.K., Doran, P.T., Kulbe, T and Andersen, D.T. (2001). Spectrofluorometric characterization of aquatic fulvic acids for determination of precursor organic material and general structural properties. Limnol. Oceanogr., 46, 38 8. 

Although many quantitative applications of acid-base titrimetry have been replaced by other analytical methods, there are several important applications that continue to be listed as standard methods. In this section we review the general application of acid-base titrimetry to the analysis of inorganic and organic compounds, with an emphasis on selected applications in environmental and clinical analysis. First, however, we discuss the selection and standardization of acidic and basic titrants. 

Here the authors found that the penicillin anion (P ) could be extracted efficiently with a secondary amine (Amberlite LA-2) in the pH range 5-7 where the product is most stable. This type of process is used extensively in hydrometallurgy (Chapter 11) and can be used to extract both anionic species using cations as shown earlier, or cationic species using organic acid anions. In hydrometallurgy, the system normally uses a hydrocarbon diluent, but for pharmaceutical applications more polar diluents are generally required. 

Through luck, in 1848, Louis Pasteur was able to separate or resolve racemic tartaric acid into its (+) and (—) forms by crystallization. Two enantiomers of the sodium ammonium salt of tartaric acid give rise to two distinctly different types of chiral crystal that can then be separated easily. However, only a very few organic compounds crystallize into separate crystals (of two enantiomeric forms) that are visibly chiral as are the crystals of the sodium ammonium salt of tartaric acid. Therefore, Pasteur s method of separation of enantiomers is not generally applicable to the separation of enantiomers. 

The term wine refers to the natural beverage produced from the juice of sound and ripe grapes, in strict accordance with federal and state regulations. The stabilization principles discussed will have equal application to fruit wines in general except for tartrate stabilization since tartaric acid, the primary organic acid of grapes, is not found in any other fruits commonly used in winemaking. 

In principle, the A 0(H) function is of limited interest for kinetic applications because the indicators are chemically very different from the organic substrates generally used. On the other hand, as the measurements are based on pH determination, the length of the acidity scale is limited by the pA" value of the solvents. However, very interesting electrochemical acidity studies have been performed in HF by Tremillon and co-workers, such as the acidity measurement in anhydrous HF solvent and the determination of the relative strength of various Lewis acids in the same solvent. By studying the variation of the potential of alkane redox couples as a function of acidity, the authors provide a rational explanation of hydrocarbon behavior in the superacid media.48... 

The procedure as given is generally applicable for the reduction of esters to alcohols in excellent yields. When preparing the solid normal saturated alcohols, the procedure may be modified, if desired, to permit the recovery of the acid from the unreduced ester. After the alkali is removed the alcohol layer is washed with two successive portions of 20 per cent salt solution which are discarded. Neither the strong alkali nor the salt solutions remove an appreciable amount of organic acid. A solution of 50 g. of calcium chloride in 150 cc. of water is added to the butyl alcohol solution, the mixture is steam-distilled until the butyl alcohol is removed, and the flask and contents are allowed to cool. A hole is made in the cake of solid alcohol and the water layer removed. Two liters of toluene is added and the flask warmed and shaken until the alcohol dissolves and only fine crystals of the calcium salt of the unreduced acid remain. The solution is cooled to 350 and filtered with suction. The calcium soap is removed from the filter, warmed with about 500 cc. of toluene, cooled, filtered, and washed with a little more toluene. The combined toluene solutions may be concentrated and the alcohol crystallized, or the toluene may be completely distilled and the residue vacuum distilled. The insoluble calcium... 

Many organic compounds react with carboxylic acids, acyl halides, or anhydrides in the presence of certain metallic halides, metallic oxides, iodine, or inorganic acids to form carbonyl compounds. The reaction is generally applicable to aromatic hydrocarbons. Benzene, alkylbenzenes, biphenyl, fluorene, naphthalene, anthracene, acenaphthene, phenanthrene, higher aromatic ring systems, and many derivatives undergo the reaction. 

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