Organic Chelating Agents

Several organic compounds such as acetylacetone, cupferron, and hydroxyquinoline, which are capable of forming chelates with polyvalent metal ions, have been used for extracting illuvial organic matter from Spodosols but are rather ineffective for extracting organic matter from other soil types. 

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Ceramic-grade beryllium oxide has also been manufactured by a process wherein organic chelating agents (qv) were added to the filtered beryllium sulfate solution. Beryllium hydroxide is then precipitated using ammonium hydroxide, filtered, and carefully calcined to obtain a high purity beryllium oxide powder. 

Structure and specificity of organic chelating agents. E. Bayer, Angew. Chem., Int. Ed. Engl., 1964, 3, 325-332 (36). 

A number of procedures for the determination of metals and biological samples call for the extraction of the metal with an organic chelating agent in order to remove interferences and concentrate the metal to enable detection of low levels. The urine or blood sample may be first subjected to wet ashing to enable extraction of the metal. Beryllium from an acid-digested blood or urine sample may be extracted by acetylacetone into methylisobutyl ketone prior to atomic absorption analysis. Virtually all of the common metals can be determined by this approach using appropriate extractants. 

This method is well-known and is used for the synthesis of homogeneous multicomponent metal oxide materials it includes a combined process of metal complex formation and in situ polymerization of organics. It relies on the development of complexes of alkali metals, alkaline earths, transition metals, or even nonmetals with bi- and tridentate organic chelating agents such as citric acid [40],... 

Chemical/Pharmaceutical/Other Class Organic chelating agent... 

The influence of rigidity also explains the increase in fluorescence of certain organic chelating agents when they are complexed with a metal ion. For example, the fluorescence intensity of 8-hydroxyquinoline is much less than that of the zinc complex (Figure 27-6). 

Kaolinite can be neoformed from solutions of A1 and silica only at acid pH in alkaline solutions, the tetrahedrally coordinated A1 ion in Al(OH)4 is unable to form the gibbsitelike sheet that is the precursor of the 1 1 aluminosilicate layer. Even in acid solutions, however, kaolinite crystallization is very slow at room temperature, probably because Al(OH)3 is insoluble except at very low pH. Natural organic chelating agents, such as oxalate, increase the solubility of A1 at acidic pH, thereby increasing the rate of kaolinite neoformation. 

Procter Gamble) organic chelating agent water-soluble Mg, Zn, Sn, Bi, or Ti salts filming... 

Procter Gamble) organic chelating agent aminosilane filming... 

A congruent dissolution of a silicate mineral reacting with organic chelating agents. 

Oxidation-reduction reactions in water involve the transfer of electrons between chemical species. Metal ions in water are always bonded to water molecules in the form of hydrated ions represented by the general formula, M(H20)xn+ Metals in water may be bound to organic chelating agents. Hardness is due to the presence of calcium ion and to a lesser extent to magnesium ion. 

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