Evaluation of adsorption and desorption steps in the solid-phase extraction of explosives using carbon/silica gel nanocomposites

J Sep Sci. 2015 Jul;38(14):2488-95. doi: 10.1002/jssc.201500171. Epub 2015 Jun 23.

Abstract

New series of carbon/silica gel nanocomposites, carbosils, prepared by the carbonization of starch bound to silica gel, and carbosils additionally silylated with octadecyldimethylchlorosilane were synthesized. These materials were applied as adsorbents in the solid-phase extraction of explosive nitrate esters and nitroaromatics from aqueous solutions. The adsorption and desorption steps were evaluated separately. It was found that both the molecular properties of explosives (dipole moments, orbital energies, solvation effects) and textural properties influenced by carbon deposits or octadecyl moieties have a large impact on the recovery rates. It was shown that the composites with moderate content of carbon deposits or with the highest amounts of carbon deposits and additionally silylated can be used as materials tailored for extraction of explosives from the aqueous solutions.

Keywords: Carbosils; Explosives; Nanocomposites; Quantum calculations; Solid-phase extraction.