A water-insoluble extracting solvent, trioctylamine (TOA), was solubilized in the aqueous micellar solution of a polyoxyethylene-type nonionic surfactant, polyethyleneglycol (10)-mono-4-nonylphenyl ether (PONPE-10). By mixing the solution and a polystyrene-divinylbenzene porous resin (Amberlite XAD-4), TOA was successfully impregnated into the resin. Gold(III),. platinum(II), and palladium(II) were well extracted from hydrochloric acid to the TOA-impregnated resins. The extents of the extraction of platinum(II) and palladium(II) increased with increasing the amount of TOA impregnated. The TOA-impregnated filter disk was also prepared by passing aqueous mixture of PONPE-10 and TOA through an Empore disk involving polystyrene-divinylbenzene. The disk was useful for concentrating precious metals in water prior to their graphite furnace atomic absorption spectrometric analysis. (c) 2006 Elsevier Ltd. All rights reserved.