Retention of Heavy Metals and Their Separation on Silica Gel Modified with Calconecarboxylic Acid

Abstract

Sorption of 35 metal ions on silica gel impregnated with a mixture of Aliquat 336 and calconecarboxylic acid was investigated. It was found that the complexation of metals is relatively rapid, and the relative capacity of the sorbent is different for various metals and increases with pH. Only alkali metals are not retained on the sorbent, and alkaline earth metals are retained from solutions of pH > 4, contrary to other metal ions. The retained metals can be eluted from the sorbent with dilute solutions of hydrochloric or perchloric acid without elution of the chelating reagent The sorbent was used for the preconcentration of trace amounts of heavy metals from aqueous solutions in the presence of macro-amounts of sodium, potassium, calcium, and magnesium as well as for the separation of some metal ion mixtures by extraction chromatography.