ion exclusion

ion exclusion

[′ī‚än iks‚klü·zhən]
(chemistry)
Ion-exchange resin system in which the mobile ions in the resin-gel phase electrically neutralize the immobilized charged functional groups attached to the resin, thus preventing penetration of solvent electrolyte into the resin-gel phase; used in separations where electrolyte is to be excluded from the resin, but not nonpolar materials, as the separation of salt from nonpolar glycerin.
References in periodicals archive ?
(2009) and Rouphael et al., (2012) who observed Na ion exclusion in grafted watermelon, cucumber and pumpkin respectively.
Various analytical parameters (column and/or chromatographic system: reversed phase, ion exclusion, porous graphite; sensor: phenylalanine, salicylic, p-hydroxybenzoic and terephthalic acids; mobile phase: concentration of organic solvent, pH; detector: photometric, electrochemical, fluorescence, MS) were tested to obtain optimal conditions for the separation and detection.
Aromatic acids (p-hydroxybenzoic, salicylic, or terephthalic) used as sensors, as well as products of their reaction with hydroxyl radicals, may be separated by reversed phase or ion exclusion chromatography [8, 17, 20, 21].
The salinity tolerance mechanisms of Aeluropus species include cellular, organizational, and whole plant adaptations, such as ion compartmentation, presence of salt glands on the leaves, ion exclusion at the root, and ion partitioning in divergent organs.
"Ion exclusion is a very old separations technology, dating back to the 1970s and 1980s.
Ion exclusion uses several different separation modes (gel filtration, ion exchange, and reversed phase) to separate compounds of interest.
In their research, the scientists used a Bio-Rad ion exclusion column, Aminex HPX 87H (300 X 7.8 mm), thermostated at 50 C, with a mobile phase of 2 mM of sulfuric acid at 0.6 ml per minute with ultraviolet (UV) (210 nm) and refractive index (RI) detectors in tandem.
Termed ion-moderated partitioning, this unique process enables these resins to separate compounds via multiple modes of interaction, involving a combination of ion exclusion, ion exchange, ligand exchange, size exclusion, reversed phase and normal phase partitioning.
These include enhanced carbon inputs, root ion exchange and ion exclusion mechanisms, root exudates, and radial oxygen diffusion from roots (Armstrong 1975); hydraulic redistribution of soil water (Caldwell and Richards 1989; Dawson 1993; Burgess et al.
All correlations were significant at the 0.0001 level of probability, r values being 0.7 or above (Table 2), indicating the importance of shoot saline ion exclusion as a salinity tolerance mechanism in Chloridoid grasses.
Prevail Carbohydrate ES HPLC Columns offer performance superior to silica-based amino columns and ion exclusion columns.
Plants may regulate shoot ion concentrations by several means: intracellular ion compartmentation (Gorham et al., 1985), ion exclusion at the root cortex (Leonard, 1983), ion reabsorption by xylem parenchyma cells (Yeo et al., 1977), redistribution to senescing leaves (Yeo and Flowers, 1984), and ion secretion via salt glands (Liphschitz and Waisel, 1982).