Aminobenzenesulfonamide functionalized SBA-15 nanoporous molecular sieve: a new and promising adsorbent for preconcentration of lead and copper ions.

A rapid method for the extraction and monitoring of nanogram level of Pb2+ and Cu2+ ions using uniform silanized mesopor (SBA-15) functionalized with aminobenzenesulfonamide groups and flame atomic absorption spectrometry (FAAS) is presented. Aminobenzenesulfonamide functionalized SBA-15 was synthesized according to procedure in the literature and the presence of organic groups in the silica framework was demonstrated by FT-IR spectra. The functionalized product showed the BET surface area 110 m2/g and pore diameter 5.1 nm, based on adsorption-desorption of N2 at 77 K. The effect of several variables such as (amount of adsorbent, stirring time, pH and presence of other ions in the medium) has been studied. Lead and copper were completely extracted at pH greater than 3 after stirring for 10 min. The maximum capacity of the adsorbent was found to be 191.3 +/- 1.4 and 155.0 +/- 1.0 microg of lead and copper ions/mg functionalized SBA-15, respectively. The preconcentration factor of the method was found to be 200. The detection limit of the technique was 3.4 and 0.4 ng/mL for Pb2+ and Cu2+, respectively. The applications of this methodology for real samples were examined by various water type, black tea and pepper samples.