Ethylenediaminetetraacetic acid, values

Nickel also is deterrnined by a volumetric method employing ethylenediaminetetraacetic acid as a titrant. Inductively coupled plasma (ICP) is preferred to determine very low nickel values (see Trace AND RESIDUE ANALYSIS). The classical gravimetric method employing dimethylglyoxime to precipitate nickel as a red complex is used as a precise analytical technique (122). A colorimetric method employing dimethylglyoxime also is available. The classical method of electro deposition is a commonly employed technique to separate nickel in the presence of other metals, notably copper (qv). It is also used to estabhsh caUbration criteria for the spectrophotometric methods. X-ray diffraction often is used to identify nickel in crystalline form. 

Electroless Deposition of Copper. The basic ideas of the mixed-potential theory were tested by Paunovic (10) for the case of electroless copper deposition from a cupric sulfate solution containing ethylenediaminetetraacetic acid (EDTA) as a complexing agent and formaldehyde (HCHO) as the reducing agent (Red). The test involved a comparison between direct experimental values for and the rate of deposition with those derived theoretically from the current-potential curves for partial reactions on the basis of the mixed-potential theory. 

Secondary antioxidants, i.e., sequestrants or chelators, are important compounds in the prevention of lipid oxidation. The effect of chelators tested varied with the different compounds. Of those chelators tested, ethylenediaminetetraacetic acid (EDTA, tetrasodium salt) and sodium phytate were the most effective inhibitors of lipid oxidation (so indicated by low hexanal and TEARS values) and MFD (as seen by high CBB and low PIT and CBD intensity values), see Table 5. Sodium phytate was previously shown to chelate iron and thus, was proposed as a food antioxidant(7J). Sodium citrate at a concentration of 500... 

The alternative to encapsulation of free manganese (called ensomes ) is to complex the manganese(II) with a ligand embedded in the lipid bilayer ( mem-somes ). Ethylenediaminetetraacetic acid (EDTA)-dihydroxypropyldecylamine (EDTA-DDP, Fig. 2) was ligated to manganese(II) and inserted into the bilayer of liposomes [61]. The 30-nm diameter liposomes formed had an R, value at 20 MHz of 37.4 mM"1 s1. When injected into rats with implanted C5 epitheloid... 

A series of manganese(II) chelates attached to polysaccharide molecules were synthesized and the Rj values were measured [72]. Ethylenediaminetetraacetic acid (Fig. 2) chelated to manganese(II) and attached to sucrose-epichlorohydrin copolymer and aminoethyldextran yielded Rj values of 19.2 mM s and 12.8 mM s , respectively, at 10 MHz and 37°C in a 1 2.13 glycerol-water mixture. Diethylenetriaminepentaacetic acid (Fig. 2) and triethylenetetraamine-hexaacetic acid (TTHA, Fig. 2) were both conjugated to dextran molecules. Chelating of manganese(II) ions resulted in complexes with Rj values at 10 MHz... 

Figure 1 The stabihty of complexes of divalent transition metal cations. 1, Triethylenetetramine, NH2C2H4NHC2H4NHC2H4NH2 2, EDTA, ethylenediaminetetraacetic acid 3, diethylenetriamine, NH2C2H4NHC2H4NH2 4, norleucine, Me(CH2)3CH(NH2)C02H 5, 1,2,3-triaminopropane, NH2CH2CH(NH2)CH2NH2 6, ethylene-diamine, NH2C2H4NH2 7, sahcylaldehyde, 2-(HO)CgH4CHO 8, oxalic acid, HO2CCO2H. For norleucine, 4, the values for log 82 are plotted...

In order to prevent back electron transfer from MV to [Ru(bipy)3] and so maximize d cE, the Ru is reduced using a sacrificial electron donor such as triethanolamine (TEOA) or ethylenediaminetetraacetic acid disodium salt (EDTA), which when present in a high enough concentration can reduce Ru " at a rate (k ed) which competes with kb and leaves MV" formed as the stable product. The values of k d for TEOA and EDTA are 4.7 X10 mol" dm s and 1.1 X10 mol" dm s" respectively. 

The rate of increase in absorbance at 340 nm due to the formation of NADPH is directly proportional to the CK activity. The CK reaction (reaction [I]) is coupled by the auxiliary hexokinase (EC 2.7.1.1) reaction (reaction [II]) to the glucose-6-phosphate dehydrogenase (EC 1.1.1.49) indicator reaction (reaction [HI]). In these reactions, Mg + and N-acetylcysteine are required as activators to form complexes and a reactivator, respectively. To avoid the inhibition of Ca and adenylate kinase (EC 1.7.4.3) in serum samples, ethylenediaminetetraacetic acid and di(adenosine-5-) pentaphosphate must be present. The activity in serum sample decreases to 98% of initial value after a week in a refrigerator. 

Example 5. Next we look at the mathematics occurring in an important tetraprotic system, ethylenediaminetetraacetic acid, EDTA. The a diagram is given in Chapter 9, where its uses are investigated further. Find the expected pH of a standard 0.020 M Na2H2 Y solution. For the system at 20°C and ionic strength 0.1 M, published values are... 

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