USSR The theoretical foundations and applications of "mixed" adsorbents for the separation and concentration of metal ions are considered. "Mixed" adsorbents are defined as those containing two or more kinds of functional groups (with different donor sets) in a controlled proportion. Varying the proportion allows one to easily regulate the affinity of the stationary phase to metals. Experiments were carried out with the use of reversed-phase thin-layer chromatography (silica plates were

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... ted with solutions of macrocyclic compounds possessing different NO y donor sets in a nonpolar solvent). "Mixed" stationary phases were shown to be capable of providing the strongest retention for metals which are not retained most strongly on any of the parent individual adsorbents. Also possible is an improvement in the separation when the use of individual phases leads to overlapping.