Nitrilotriacetic acid chelating agent

Interestingly, retardation of either nickel or cobalt sulfidation to temperatures where MoS2 has already been formed can also be achieved by applying chelating agents, such nitrilotriacetic acid, which bind cobalt or nickel and release these elements at higher temperatures. In this way one can prepare the CoMoS phase on... 

In the condensed chelate systems, many kinds of chelating agents were used, such as ethylenediamiiie-/V,/V,/V, /V -tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), /-aspartic acid (AA), trimethylenediamine (TMD), /V,/V-dimethylethylenedi-amine (DMED), diethylenetriamine (DETA), triethylenetetraamine (TETA), and t ris(2-aminoethyl)amine (TAEA) (6). The chelating agents used are listed in Table 3.2.1. 

These molecules are flexible because rotation about single bonds is free, so they can wrap themselves around a metal ion to obtain four comfortable donor-atom-to-metal links within five-membered rings. Nitrilotriacetic acid is easily synthesized industrially from ammonia, formaldehyde, and hydrocyanic acid (the Strecker synthesis) and therefore is potentially an inexpensive but effective chelating agent. 

As an alternative to acid washing, soils can also be flushed with chelating agents. Examples of effective chelating agents include ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA), both of which readily bind and solubilize metals. Using this approach, Peters Shem (1992) have recently reported on the removal of lead from a contaminated soil. In this study, 0.1M EDTA removed 60% of the lead in a soil containing 10 000 mg lead/kg. 

Figure 12-4 Structures of analytically useful chelating agents. Nitrilotriacetic acid (NTA) tends to form 2 1 (ligand metal) complexes with metal ions, whereas the others form 1 1 complexes.

Kartal and Kose (2003) investigated the removal of arsenic from CCA-treated wood with common chelating agents (EDTA, nitrilotriacetic acid (C6H9NO6), and oxalic acid). Dual mixtures of EDTA and oxalic acid and nitrilotriacetic and oxalic acids removed about 100% of the arsenic from sawdust of the wood. However, only about 80 % of the arsenic was removed from wood chips with the same dual solutions. Once the arsenic, copper, chromium, and any other toxins have been removed from the wood, it could be used as a biofuel. 

Nitrilotriacetic acid (NTA) is a constituent of various domestic and hospital detergents and is a common water contaminant. NTA forms water-soluble chelate complexes with various metal ions, including iron, at neutral pH. Its iron complex, Fe-NTA, is a known potent nephrotoxic agent. The renal toxicity is assumed to be caused by the elevation of serum free-iron concentration following the reduction of Fe-NTA at the luminal side of the proximal tubule, which generates reactive oxygen species and leads to enhancement of lipid peroxidation. 

Alkylphosphonate groups are monodentate donors of intermediate hardness that may replace carboxylate groups in chelating agents such as nitrilotriacetic acid (NTA), ethylenediaminetetra-acetic acid (EDTA), and diethylenetriaminepentaacetic acid (DTPA). The corresponding ligands nitrilotrimethylenephosphonic acid (NTP), 1, ethylenediaminetetramethylenephosphonic acid (EDTP),... 

Removal of lead from water is performed generally by precipitation as carbonate or hydroxide with or without coagulation. Chelation with EDTA, nitrilotriacetic acid, or other agents is another usual treatment followed by recovery using precipitation, electrolysis, or chemical oxidation (Borrell-Damian and Ollis, 1999). However, most of these treatments are expensive, and some other ways of lead elimination from wastewater are necessary to be developed. 

Iron Oxides. Chelated iron oxide, using nitrilotriacetic acid [139-13-9] and EDTA, has been studied as an alternative oxygen source (35). Iron oxide which is often difficult for the microbes to access, is made more available by chelating agents. 

Fio. IS.—-Inhibition of /J-Galactoaidase of E. coli, ML 309, with Chelating Agents, (l,2-Cyclohexylenedinitrilo)tetraacetic acid (Chel CD) and Nitrilotriacetic acid (Chel NTA), (See also Table X. 0.05 M 2-Amino-2-(hydroxymethyl)-l,3-propanediol-HCI buffer, pH 7.6 20° 3.33 X 10 M o-nitrophenyl /3-D-galactoside. A = enzyme activity in the presence of inhibitor Ao >= enzyme activity in the absence of inhibitor.)... 

Schwarzenbach (1945) has developed the use of such chelating agents as nitrilotriacetic acid (a), ethylenediaminetetra-acetic acid (b) and 1 2 diaminocyclohexanetetra-acetic acid (c). 

Nitrilotriacetic acid (NTA) is the second most common aminopolycar-boxylic acid used for titrations. It is a tetradentate chelating agent and has the structure... 

The use of formaldehyde in the manufacture of chelating agents represents a modest but important market for formaldehyde. Approximately 75% of the formaldehyde used in the synthesis of chelating agents is consumed in the manufacture of ethylenediaminetetraacetic acid (EDTA). The remaining 25% is used to produce nitrilotriacetic acid (NTA), primarily for export (Gerberich et al. 1980). 

Salts of polyacetic acids, e.g., ethylenediamine tetraacetic acid (EDTA) and nitrilotriacetic acid (NTA), have long been known to be very effective chelating agents [95], The chelating ability of NTA has been found to be comparable to that... 

EDTA is used to prevent pesticides from precipitation in hard-water solutions, to soften water in soap and detergent, and to prevent the catalytic effects of metal ions present in water in the cold rubber SBR process [57]. EDTA attached to iron catalyzes the direct hydroxylation of phenolic compounds [58] it also is the best way to supply iron-deficient citrus trees [59]. Other chelating agents include nitrilotriacetic acid (NTA) made from ammonia and diethylenetriamine pentacetic acid from diethylenetriamine [60]. 

Because of the involvement of metal ions in degradation reactions, the inclusion of a chelating agent is often advocated. The most commonly used chelating agent are the various salts of EDTA. In addition, (3-hydroxyethylenediaminetriacetic acid (HEDTA), diethylenetriamine-pentaacetic acid (DTPA) and nitrilotriacetate (NTA) have been assessed for their efficiency in stabilizing, e.g., isoniazid solutions (Ammar et al. 1982). 

NTA nitrilotriacetic acid, used as a substitute chelating agent instead of phosphate, also used in analysis (forms complexes with many metals)... 

Hampshire . [W.R. Orace/Oiganics] Nitrilotriacetic acid w salts or glycine derivs. chelating agent, detergent builder for laundry detogents, specialty cleaners, water treatment, textiles, metal finishing. 

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