Solid phase extraction of metal ions on resins impregnated with carboxylates of phenolic oligomers

Four types of resins impregnated with phenolic oligomer carboxylic acids ha ve been prepared to investigate the adsorption behavior of divalent metal i ons, such as lead, copper, zinc, and cobalt, and leakage of the impregnated extractants to the aqueous solution. The loss of the extractants to the aq ueous solution was negligible except for the monomeric extractant. The impr egnated resins have been found to be capable of extracting metal ions. The following sequence of metal ion selectivity was found for all resins. Pb >> Cu > Zn > Ni. This selectivity is in accordance with that observed for liquid-liquid extr action reagents. The adsorption of lead on all resins is significantly high , while that of other ions is very low. In particular, that of other metal ions on the resins impregnated by calix[4]arene carboxylate is remarkably l ow. This may be attributable to the size-exclusion effect.