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Ion-exchange beads

Hodge et al. [689] have described a method for the determination of platinum and iridium at picogram levels in marine samples, based upon an isolation of anionic forms of these elements using appropriate resins, with subsequent purification by uptake on a single ion-exchange bead. All steps are followed by radiotracers, and yields vary between 35 and 90%. Graphite furnace AAS was employed as the determinative step. [Pg.247]

Uses. Comonomer for preparation of cross-linked polymers in production of ion exchange beads and gel permeation chromatography polystyrene beads polymerization monomer for synthetic rubber, drying oils, and casting resins... [Pg.289]

In this respect the dense nonporous ion-exchange material of a membrane may be viewed as a one-phase medium. In contrast to this a porous bulk ion-exchanger (e.g., an ion-exchange bed or a single microporous ion-exchange bead) is a two-phase medium with the possibility for each ion to be in either one of the two phases—in the ion-exchange matrix proper or in the aqueous pore. [Pg.3]

Figure 2.20 Representation of the interaction between the fixed charges of the ion-exchange beads and the cAMP and AMP molecules. Figure 2.20 Representation of the interaction between the fixed charges of the ion-exchange beads and the cAMP and AMP molecules.
CfCls was first reported by Burns et a/., in 1973, synthesized by the ion-exchange bead route described above. As more = 351 y) became available on the /rg scale, another... [Pg.168]

Soft tissue Spiked sample wet digested purification by anion exchange loaded into a single ion-exchange bead as a point source for MS Isotope dilution-MS (isotopic quantification) <5 pg/L 77% Kelley and Fassett 1983... [Pg.319]

Estimate of the HETP intradiffusion coefficients, when based on HETP dependence on concentration, has been shown to be close in value to the quantity calculated with the theoretical formula obtained by using the model of centrosymmetrical diffusion in an ion-exchanger bead [89,90]. The values in this formula of r /D, where r is the effective particle radius, were determined in thin-layer kinetic experiments with the same ion-exchanger fraction. [Pg.83]

Figure. 2. SEM images of the fracture(a) and magnification of macro pores(b) of PAN-KCoFC composite ion exchanger beads. Figure. 2. SEM images of the fracture(a) and magnification of macro pores(b) of PAN-KCoFC composite ion exchanger beads.
Concentration of dilute electrolytes An ion-exchange column is effective for collecting ionic substances from large volumes of dilute solutions. By elution employing a small volume of solution, a considerable concentration effect can be achieved. As examples may be cited the concentration of cations and anions in natural waters, beryUium from bones, copper from milk, and silver in atmospheric precipitation. Ion-exchange beads have been proposed as chemical microstandards since they can retain small measurable quantities (10 g) of ions such as sodium, potassium, calcium, and uranium. It is highly desirable that the beads be uniform in size and homogeneous in the trace constituent. [Pg.506]

Impurities, sources of louic liquids for reactions Ion exchange, bead form celluloses Cellex D Cellex CM matrices resins Sephadex Sepharose Ionization constants... [Pg.587]

Fig. 9 Scanning electron microphotograph (300 x) of the composite ion-exchange material (top) and schematic representation of the ion-exchanger beads present in a network of interlaced PTFE (bottom). Fig. 9 Scanning electron microphotograph (300 x) of the composite ion-exchange material (top) and schematic representation of the ion-exchanger beads present in a network of interlaced PTFE (bottom).

See other pages where Ion-exchange beads is mentioned: [Pg.1111]    [Pg.2033]    [Pg.70]    [Pg.146]    [Pg.525]    [Pg.464]    [Pg.215]    [Pg.40]    [Pg.40]    [Pg.2]    [Pg.644]    [Pg.544]    [Pg.545]    [Pg.418]    [Pg.497]    [Pg.354]    [Pg.367]    [Pg.368]    [Pg.371]    [Pg.168]    [Pg.94]    [Pg.1791]    [Pg.184]    [Pg.376]    [Pg.376]    [Pg.377]    [Pg.350]    [Pg.471]    [Pg.472]    [Pg.506]    [Pg.280]    [Pg.2225]    [Pg.473]    [Pg.1423]    [Pg.1425]    [Pg.1433]   
See also in sourсe #XX -- [ Pg.192 ]




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