Di- and tri-carboxylic acid

Di- and tri-carboxylic acids. Resolution by anion-exchange chromatography. [Bengtsson and Samuelson Anal Chim Acta 44 217b 1969.]... 

Chemical analysis revealed that commercial food grade copper chlorophyllin is not a single, pure compound, but is a complex mixture of structurally distinct porphyrins, chlorin, and non-chlorin compounds with variable numbers of mono-, di-, and tri- carboxylic acid that may be present as either sodium or potassium salts. Although the composition of different chlorophyllin mixtures may vary, two compounds are commonly found in commercial chlorophyllin mixtures trisodium Cu (II) chlorin Cg and disodium Cu (II) chlorin which differ in the number of... 

In his review, Miller (1998) recalls other compounds that have been synthesized under primitive Earth conditions, such as di- and tri-carboxylic acids, C2-C10 fatty acids, porphin, imidazoles, and he also mentions products that have not been... 

A. Water, polyhydric alcohols, aminoalcohols, oxyacids, polyphenols, di- and tri-carboxylic acids. 

Sugar acids, mono-, di-, and tri-carboxylic acids, keto-, hydroxy-acids as well as unsaturated organic acids are present in foods. While uronic acids participate in the browning reaction, others might accelerate or retard the reaction. 

Carboxylic acids. Of these pyridine acids there are mono-, di-, and tri-carboxylic acids known, which are obtained by oxidation of the corresponding mono-, di-, and tri-methyl homologues. One of the mono-carboxylic acids is known as nicotinic acid and is obtained... 

Dissolved organic species have been known to exist in sedimentary basin formation waters since before the turn of the century (5.6.71. A host of aqueous organic species have been identified in sedimentary formation waters including hydrocarbons, mono-, di- and tri-carboxylic acid anions, keto and hydroxy-acids, amino acids, phenols, cresols, and hydroxybenzoic acids (8.9.10.11.121. 

There is confusion in the literature concerning the nature of the polymers used in glass-ionomers. This stems from the early research of Wilson et al., who studied a range of mono-, di- and tri-carboxylic acid monomers in polymers for cement formation, including itaconic and tricarballic acid [20] and this has led to the assumption that these must be used in practical cements. In fact proprietary materials are all based on the two polymers previously mentioned. 

Hydrolysis of cyanocobalamin for 5 min with concentrated hydrochloric acid liberated the nucleotide moiety the aminopropanol fragment was retained and there was little effect on either the cyanide group or the amide linkages. This cobalt-containing hydrolytic fragment is identical with Factor B, a microbiologically active compound from fecal material. Further hydrolysis of Factor B yielded corresponding mono-, di-, and tri-carboxylic acids in which the nucleotide moiety was absent. These could also be converted to the parent compound. Factor B, by way of the intermediate mixed anhydride and treatment with ammonia. 

Di- and tri-carboxylic acids such as oxalic acid, citric acid, etc. elute between the exclusion volume and the totally permeated volume. Apart from Donnan exclusion, the predominant separahon mechanism is, in this case, mainly steric exclusion. The retention is determined by the size of the sample molecule. Be-... 

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