Calcium nitrilotriacetate

CeHioMgOiOf Magnesium bis(hydrogen malonate) dihydrate, 44B, 22 CgHiiCaNOs, Calcium nitrilotriacetate dihydrate, 38B, 688 CeHiiK02, Potassium caproate, 16, 432... 

Nitrilotriacetic acid (NTA) and especially its trisodium, monohydrate salt, N(CHC00Na)3,H20. NTA is primarily manufactured by Monsanto Chemical Company, Inc. and Hampshire Chemical. Anhydrous NTA has a MW of 257. It is generally supplied for incorporation into formulations as 40% NTA (42.8% NTA Na3 H20), (Hampene 150). Its chelating activity at a pH level of 11 is 156 mg CaC03 per gram of chelant. That is, 10 ppm of chelant will sequester 1.56 ppm of calcium hardness. 

Co-builders such as nitrilotriacetic acid or polycarboxylates also may be incorporated into the detergent formulation. Wash performance of detergents decreases with increasing calcium concentration. Protease performance varies, but high calcium concentrations tend to reduce protease performance. Therefore it is an advantage to add a builder system to the detergent. Proteases need a small amount of calcium for the sake of stability, but even with the most efficient builder systems, stability during wash is not a problem. 

Chromatographic System (See Chromatography, Appendix IIIA.) Set up the system with reference to High-Performance Liquid Chromatography. The chromatograph has a 254-nm detector and a 15-cm x 4.6-mm column that contains 5-to 10-mm porous microparticles of silica bonded to octylsilane (Zorbax 8, or equivalent). Set the flow rate to about 2 mL/ min. Chromatograph three replicate injections of the Standard Preparation, and record the peak responses as directed under Procedure. The relative standard deviation is not more than 2.0%, and the resolution factor between nitrilotriacetic acid and Calcium Disodium EDTA is not less than 4.0. 

Procedure Separately inject equal volumes (about 50 jxL) of the Standard Preparation and the Test Preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. The retention times are about 3.5 min for nitrilotriacetic acid and 9 min for Calcium Disodium EDTA. The response of the nitrilotriacetic acid peak of the Test Preparation does not exceed the difference between the nitrilotriacetic acid peak responses obtained from the Standard Preparation and the Test Preparation. 

Edetic acid (EDTA) and nitrilotriacetic acid (NTA) have been widely used as sequestering agents for calcium and other metals, They are very soluble in water and difficult to analyse, However, they are of relatively low toxicity and are unlikely to require routine monitoring except in exceptional circumstances,... 

Nitrilotriacetic acid trisodiura salt, monohydrate. High purity dry form of PERMA KLEER NTA 150. White crystalline power. Chelating value at pH 11 355 mg calcium per g... 

In the first nonphosphate version of a commercial product, phosphate was replaced by NTA (trisodium nitrilotriacetate), a powerful builder, comparable to condensed phosphate in its efficacy in sequestering calcium ions in the washing solution. Because of reports of adverse teratogenic effects in laboratory experiments, this builder was withdrawn from the market toward the end of 1971. It was replaced by sodium citrate, an environmentally more acceptable but inherently less powerful calcium sequestering agent. At the same time surfactant levels were increased by a factor of about three. What had happened in practice (if not in theory) was that higher levels of surfactants had been introduced to compensate for the loss in the builder contribution to washing efficacy provided previously by phosphate. 

In sequestration (chelation) the hardness ions are bound to the builder in the form of soluble complexes. Phosphates, citrates, and nitrilotriacetic acid (NTA) are examples of this class of builder compound. Table 8.3 lists the calcium binding capacities of various builders. Other strongly chelating compounds exist, such as phosphonates and EDTA, but they are generally not extensively used in HDLDs. The most efficient builder is sodium tripolyphosphate (STPP). Unfortunately, tripolyphosphate has been identified as a possible cause of eutrophication in lakes and rivers. It is severely controlled and even banned in several countries. As a result, most countries in North America and Europe have converted to nonphosphate formulations. Other regions are also gradually imposing restrictions on the use of phosphates. 

The low molecular weight sodium salts of ethylenediaminetetracetic acid (EDTA) and nitrilotriacetic acid (NTA) soluble in water, are effective in the control of scaling in steam raising equipment. The action of these additives is to form complex ions with calcium and magnesium hardness. The action of EDTA is similar to ion exchange, and may be described by the simplified equation ... 

With carboxylic acids Ca forms so-called calcium soaps, which abolish the cleaning effect of the soaps. With synthetic ligands like ethylenediaminetetraacetic acid (EDTA) or nitrilotriacetic acid (NTA), Ca forms very stable complexes these are used to sequester Ca in order to enhance the effect of soap. The same applies also to other detergents. 

Several other complexing reagents are effective masking agents when added to the sample but not to the mobile phase. Nitrilotriacetic acid (NTA) masks a 10- to 100-fold excess of aluminum] 111), copper]II), nickel]II) or iron]III) when magne-sium]II), calcium and manganese] ) are to be determined by IC. Analysis of rare-... 

Besides calcium minerals, the growth of a few other inorganic salts on solid surfaces has also been studied. Silica is another important biomineral [81, 182], yet it has not been studied extensively in the context of surface mineralization. Tahir et al. synthesized a new nitrilotriacetic acid (NTA)-terminated alkenethiol, which can self-assemble on gold surfaces. Using the well-known coordination of Ni + and NTA, the enzyme silicatein could be immobilized on the surface of gold nanoparticles. Exposure of these functional particles and control experiments in the absence of silicatein showed that silica precipitates only on silicatein-modified... 

Other examples of set retarders are ethylenediamine tetraac-etic acid and nitrilotriacetic acid, or a combination of these compounds (11). StiU another example of a set retarder for Portland cement is a copolymer formed from a monomer of 2-acrylamido-2-methyl-l-propane sulfonic acid. Examples of set retarders for calcium aluminate cements are polymeric phosphate salts such as sodium tripol q3hosphate (12). 

Gluconic acid naturally occurs in plant, fruit, and foodstuffs, such as wine (up to 0.25%) and honey (up to 1%). Similar to other outstanding properties, gluconic acid has a good chelating capacity in alkaline pH its action is comparatively better than ethylenediaminetet-raacetic acid, nitrilotriacetic acid, and other chelators. Calcium, iron, copper, aluminum, and other heavy metals are firmly chelated in alkaline solution. It has been extensively used in the cleaning and construction industries as an additive to increase cement resistance and stability under extreme climatic conditions (Ramachandran et al., 2006). 

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