Ion-exchange affinity

Chromatography Paper ion exchange affinity thin-iayer ... 

Extremely high ion exchange affinities are however sometimes observed for alkali metals (e.g. Cs) and transition metal ion complexes in clay minerals and zeolites. The objective of this paper is to give an account of the factors which are involved in these high selectivity phenomena. The discussion will be focussed mostly on montmorillonites and faujasites as representatives of the phyllosilicate and tectosilicate groups. 

The introduction of unsaturated aromatic compounds also leads to better charge delocalization and enhanced ion exchange affinity. This is+ rerified by 1) the higher free energy of exchange versus in biprotonated histammonium (83) (AC ... 

A solution composed of several solutes is injected at one end of the column and the eluent carries the solution through the stationary phase to the other end of the column. Each solute in the original solution moves at a rate proportional to its relative affinity for the stationary phase and comes out at the end of the column as a separated band. Depending on the type of adsorbent or the nature of the solute-adsorbent interaction, they are called adsorption, ion-exchange, affinity, or gel filtration chromatography. 

Carrier facilitated transport (CFT) Ion conduction Ion exchange Affinity separation... 

A. Factors Influencing the Ion-Exchange Affinity of Amino Acids... 

Whereas the ion-exchange affinity of various mineral ions to ion exchangers is reasonably well understood, the ion-exchange affinity of various amino acid ions is not because of their more complex nature. 

Many publications of the last decades reported the preparation, characterization, and performances of various types of adsorptive membrane. Ion exchange, affinity, reverse phase, or hydrophobic interaction membrane chromatography have been described. In the following, various methods involved in the preparation of different classes of adsorbers will be discussed. 

The analytical methods used must be reproducibly validatable to ensure regulatory compliance for the FDA and confidence in the quality of a potentially successful, marketable product. Some of the most often used analytical methods are the chromatographic techniques such as size exclusion, ion exchange, affinity chromatography, and reverse-phase chromatography. 

Available functional groups are listed in Table 7.1. ° Silica can also be functionalized with groups suitable for ion exchange, affinity chromatography or... 

Separations of common inorganic anions are quite fast, as indicated by the migration times in Table 10.5. It is also possible to obtain a baseline because of the greater ion-exchange affinity for iodide the electrophoretic mobilities of bromide and iodide are almost identical. A separation of several inorganic anions is illustrated in Fig. 10.15. 

If you work with solutes such a steroids, isomers or naphthalene derivatives, or in a separation mode such as ion exchange, affinity chromatography, chiral chromatography etc., you should certainly check the influence of the temperature on the selectivity, but not just in the range 30 0 °C. 

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