Organic acids general characterization

Fluorinated Acids. This class of compounds is characterized by the strength of the fluorocarbon acids, eg, CF COOH, approaching that of mineral acids. This property results from the strong inductive effect of fluorine and is markedly less when the fluorocarbon group is moved away from the carbonyl group. Generally, their reactions are similar to organic acids and they find apphcations, particularly trifluoroacetic acid [76-05-1] and its anhydride [407-25-0] as promotors in the preparation of esters and ketones and in nitration reactions. 

Frimmel,F. H. (1992). Isolation and general characterization of organic acids frompore water. In Progress in Hydrogeochemistry, Matthess, G., Frimmel, F., Hirsch, P., Schulz, H. D., and Usdowski, H.-E., eds., Springer, Berlin, pp. 9-13. 

Unsubstituted tetrazole behaves as an organic acid with acidity close to that of acetic acid. In general, depending on the substituent in position 5, tetrazole ionization occurs in the range from —0.8 unit of the Hq scale to 7 unit of the pH scale. Proton elimination from 1H- and 277-tetrazoles 24 and 106 results in formation of the tetrazolate anion (tetrazolide) 7 (Scheme 5) characterized by high aromaticity and good Jt-electron delocalization. 

While most columns are general-purpose, a number of columns are marketed for specific applications. Examples are columns for environmental analysis (carbamates, polynuclear aromatic hydrocarbons) or food testing (amino acids, organic acids, sugars). These columns are often shipped with chromatograms demonstrating the performance of the specific application. More examples of specific applications and GPC columns for polymer characterization are described in Chapter 7. 

PAL and TAL are apparently represented to a very limited extent in bacteria, this presumably accounting for the general paucity of phenylpropanoids in such organisms. Isolation and characterization of PALs have, however, been described for R. toruloides Streptomyces maritimus Photorhabdus luminescens Sorangium cdlulosum, and Streptomyces verticillatus with the -cinnamic acid (3) so-formed being considered, for... 

In general terms, lignite and anthracite coals appear to contain much lower proportions of the volatile organic componnds (10) than the bituminous coals, although alkaline extraction of lignite (and bituminous coal) will yield organic acids of various types that can be characterized. On the other hand, the hexane-soluble portion of the pyridine extracts that were obtained at 50°C (120°F) from coal (carbon content 83.6% w/w) have been identified as alkylated chrysenes as well as alkylated picenes in addition to a mixture of C2g, C29, and C30 paraffins. There were also indicates of the presence of an alicyclic or methyl-substituted five-ring (cat-condensed) system as well as l,2,5,6-dibenzanthracene(s) (Table 10.1). 

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