Selective solid-phase extraction and separation of trace gold, palladium and platinum using activated carbon modified with ethyl-3-(2-aminoethylamino)-2-chlorobut-2-enoate

Activated carbon was chemically modified with ethyl-3-(2-aminoethylamino)-2-chlorobut-2-enoate to obtain a material for selective solid-phase extraction of trace Au(III), Pd(II) and Pt(IV) prior to their determination by inductively coupled plasma atomic emission spectrometry. Experimental conditions such as effects of pH, shaking time, sample flow rate and volume, elution and interfering ions were studied. The ions Au(III), Pd(II) and Pt(IV) can be quantitatively adsorbed on the new sorbent from solution of pH 1. The adsorbed ions were then eluted with 0.1 mol L-1 hydrochloric acid and containing 4% thiourea. Many common ions do not interfere. The adsorption capacity of the material is 305, 92, and 126 mg g(-1) for Au(III), Pd(II) and Pt(IV), respectively, and the detection limits are 5, 11 and 9 ng mL(-1). The relative standard deviation is less than 3.0% (n=8) under optimum conditions. The method was validated by analyzing two certified reference materials and successfully applied to the preconcentration and determination of these ions in actual samples with satisfactory results.