Palladium adsorption and preconcentration onto thiol- and amine-functionalized mesoporous silicas with respect to analytical applications

Amine- and thiol-functionalized mesoporous SBA-15 silicas were synthesized, characterized and then applied to solid phase extraction of palladium from digested environmental samples (soil and road dust) with subsequent determination by slurry sampling graphite furnace atomic absorption spectrometry (GFAAS). The SBA-15 material was synthesized by the template method and fully characterized by a broad range of instrumental techniques. Functionalized samples were able to adsorb Pd(II) ions quickly and quantitatively from a wide range of concentrations and pH values. The adsorption uptakes were as high as 190 mg g(-1) and 68 mg g(-1), for thiol- and amine-modified silicas, respectively. GFAAS was used for fast and simple determination of palladium preconcentrated on the silica matrix. The proposed combination of Pd(II) preconcentration and Pd-loaded sorbent slurry sampling GFAAS technique application allowed reaching an Pd(II) enrichment factor of 25 and LOD of 4.8 ng g(-1).