Preparation of dendrimer-like polyamidoamine immobilized silica gel and its application to online preconcentration and separation palladium prior to FAAS determination

A amino-terminated G 4.0 dendrimer-like polyamidoamine (PAMAM) immobilized silica gel (PAMAMSG) was prepared with a divergent method by repeating two processes: (1) Michael addition of methyl acrylate (MA) to surface amino groups; and (2) amidation of the resulting esters with ethylenediamine (EDA) from γ-aiminopropyl silica gel (APSG) core. It was then used for the first time as microcolumn packing for the flame atomic absorption spectrometry (FAAS) determination of trace or ultra trace Pd(II), after flow injection (FI) online preconcentration and separation process. A limit of detection (LOD) of 3.9 ng ml−1 was achieved when 0.200 μg ml−1 Pd(II) was preconcentrated in 0.2 mol l−1 HCl medium with a sampling flow rate of 6.0 ml min−1 for 60 s and the relative standard deviation (R.S.D.) was 1.7%. The proposed method was successfully used for the determination of Pd in two metallurgical samples.