Methods for separation of ions by ion-exchange, ion-pair, and zwitterion ion chromatography share at least one common thread--the induced formation of a cation-anion pair in the stationary phase. Selectivity can be defined as the relative ability of sample ions to form such a pair. Examples are given in anion-exchange chromatography to show the effect of variations in the geometry, bulkiness an...

the major foible of dental ceramics is their brittle nature. therefore, the producers of these materials have focused on the “strength” issue. a method of increasing strength is ion exchange on porcelain surface which leads to formation of a compressive crust that opposing forces should overcome before developing a crack. in current study, ion exchange in two types of porcelain, ceramco ii whic...

the objective of this research is to find an economically attractive alternative method for hydrodesulfurization of petroleum fractions and to select a suitable adsorbent for this process.deep desulfurization of transportation fuels (gasoline, diesel, and jet fuels) is being mandated by governments and is also needed for future fuel cell applications. however, it is extremely difficult and cost...

reversed-phase (ISRP) material. Proteins do not adsorb on the hydrophilic exterior surfaces and do not penetrate into the hydrophobic interior surfaces, while analytes can reach the interior surfaces and be separated. (Reproduced with permission from Perry JA (1991) The internal surface reversed phase. Concept and applications. Journal of Liquid Chromatography 13: 1047}1074.) Gelfferich F (1962...

Enriched stable isotopes of many elements have been widely used in many aspects and such isotopes have been primarily used as the tracer for agricultural and biochemical studies and the availability of the isotopically labeled compounds have been now extensively increasing. Chemical exchange separation of isotopes is based on the equilibrium fractionation of isotopes between two phases, ion exc...

A new chromatographic procedure was proposed for the separation of propranolol (PRN) enantiomers based upon enantioselective chiral ligand-exchange chromatography. The separation was carried out on a short C8 column leading to considerably short separation time. L-alanine and Cu2+ were applied as chiral selector and central bivalent complexing ion, respectively. It was found that the kind of co...

An ion-exchange process can be an effective route to synthesize new quasi-equilibrium phases with a desired crystal structure. Important layered-type battery materials, such as LiMnO2 and LiNi(0.5)Mn(0.5)O2, can be obtained through this method from a sodium-containing parent structure, and they often show electrochemical properties remarkably distinct from those of their solid-state synthesized...

A new chromatographic procedure was proposed for the separation of propranolol (PRN) enantiomers based upon enantioselective chiral ligand-exchange chromatography. The separation was carried out on a short C8 column leading to considerably short separation time. L-alanine and Cu2+ were applied as chiral selector and central bivalent complexing ion, respectively. It was found that the kind of co...