Anion high capacity

Nowak, M. and Seubert, A., Application of experimental design for the characterization of a novel elution system for high capacity anion chromatography with suppressed conductivity detection, /. Chromatogr. A, 855, 91,1999. 

The anionic exchange capacity for some LDH compositions is reported in Fig. 13. The values range from 450 to 200meq/100g lower values are difficult to reach since the ratio R = would be too high to maintain... 

IC column anion guard anion separators in tandem packed with low capacity anion exchange resin anion suppressor packed with high capacity cation exchange resin. Other IC column resins may be used eluent 1.5 mm NaHC03. 

Small and co-workers [6] at Dow Chemical discovered that alkali and alkaline earth metals could be separated and determined analogously to anions with a cation exchange separation and an anion stripper now commonly known as a suppressor. With the latest developments in high efficiency columns and high capacity suppressors, it is possible to determine the common alkali and alkaline earth metals along with ammonia in a single injection run of less than 15min (Fig. 2.1). 

Shown in Fig. 2.8 is a schematic diagram of the Dionex ion exchange liquid chromatograph used by Smee et al. [40], The instrumentation consists essentially of a low capacity anion exchange column, the separator , a high capacity cation exchange column, the suppressor and the detection system, a high sensitivity conductivity meter and recorder. 

In a more recent work Ito [101] has described a simple and highly sensitive ion chromatographic method with ultraviolet detection for determining iodide in seawater. A high-capacity anion exchange resin with polystyrene-divinylbenzene matrix was used for both preconcentration and separation of iodide. Iodide in artificial seawater (salinity, 35 % ) was trapped quantitatively (98.8 0.6%) without peak broadening on a preconcentrator column and was separated with 0.35M sodium perchlorate+ 0.10M phosphate buffer (pH 6.1). On the other hand, the major anions in seawater, chloride and sulphate ions, were partially trapped (5-20%) and did not interfere in the determination of iodide. The detection limit for iodide was 0.2pg L 1 for 6mL of artificial seawater. This method was apphed to determination of iodide (ND-18.3pg L ) and total inorganic iodine (I +I03 -I, 50.0-52.7pg L 1) in seawater samples taken near Japan. 

A high-capacity, weak-base anion-exchange resin has been prepared by suspension polymerization of methacrylic acid with DVB followed by the amination of the beads with an alkylamine. The resin has good anion-exchange properties and dimentional stability, and can be used in deionization of water as a substitute for silica... 

Anion-exchange resin useful for the extraction of copper from esters has been obtained by the amination of methylmethacrylate — DVB copolymer with hydrazine or guanidine Acryloyl chloride undergoes spontaneous polymerization with polyethylenepolyamine at room temperature to give an anion-exchange resin with high capacity and selectivity for bivalent metal ions... 

To conclude The functional anion concept opens up ne v possibilities to tailor reaction enthalpies of high capacity hydrides to vards potential applications. At present, ho vever, not much is known about how successful this method will eventually be and which material classes can be successfully altered by it. 

Sorption in most soils attains a maximum when the neutral hydroxy complex of uranium is at a maximum. However, at pH 6 and above, and in the presence of high carbonate or hydroxide concentrations, uranium may form anionic complexes such as [U02(0H)4]. The mobility of anionic uranium complexes in soil is dependent upon the nature of the soil. For example, the decrease in sorption in soil with little anion-exchange capacity may result in increased mobility however, increased sorption in soil with high anion-exchange may result in decreased mobility (Allard et al. 1982 Ames et al. 1982 Brookins et al. 1993 Ho and Doern 1985 Hsi and Langmuir 1985 Tichnor 1994). 

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