Analytical Sciences

Abstract − Analytical Sciences, 14(1), 241 (1998).

Palladium(II) Extraction and Extractant Adsorption at a Liquid/Liquid Interface
Institute of Technology andChemical Engineering, Poznan ´ University of Technology, Pl. Skl¢odowskiej-Curie2, 60-965 Poznan ´ , Poland
Interfacial tension isotherms were determined for individual palladium(II)extractants and interpreted. The followingextractants were considered: 4-alkylphenylamines containing from 6 to 14carbon atoms in the alkyl group, dihexylsul-fide,2-hydroxyethyldecyl sulfide and its partly fluorinated derivative,decylnicotiniate and N,N-dihexylpyridine-3-car-boxamide.4-Alkylphenylamines exhibited significantly stronger interfacial activitythan did the other extractants. Theyadsorbed at the hydrocarbon/water interfaces already at concentrations 10-5 M and permit to decrease theinterfacial ten-sionto 5 mN m -1 . As a result, theycan be used as a phase transfer catalyst to increase the rate ofpalladium(II) extractionwith other extractants. When used alone, the initial rate of extractionincreases with the extractant increasing hydropho-bicity,thus in the order of increased interfacial activity.