Selectivity desorbents

The remainder of the modified parfait column consisted of an MSC-1 cation-exchange and an A-162 anion-exchange bed. The elution conditions for these beds were modified to minimize contamination of eluates and to selectively desorb organic anions and cations. With the modified protocol, 20 model compounds (Table I), selected by the U.S. Environmental Protection Agency (USEPA) Health Effects Research Laboratory (HERL), were used to evaluate the recovery efficiency of the method. Recoveries were determined in the presence of 2 ppm of a humic acid supplied by HERL. 

Probably the best generally known separation process is that of chromatography where a mixture of species to be separated (mobile phase) is taken up by a sorbent (stationary phase) and then selectively desorbed in a manner governed by the relative sorption affinities of the various species for the sorbent. 

Henry and Van Lierde developed a three-compartment cell equipped with an reticulated vitreous carbon cathode mixed with ion-exchange resin and two Ti—Pt anodes separated by a Daramic diaphragm to selectively separate the vanadium from molybdenum (Henry Van Lierde, 1998). In this designed membrane reactor, the pentavalent vanadyl anion was selectively desorbed with respect to molybdenum after its reduction to a tetravalent vanadyl cation. Consequently, 93% vanadium recovery yields were obtained. 

Selectively desorbs or sputters unreacted or weakly bound species. 

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