Solid phase extraction of explosives on Ni-doped carbosils prepared by mechanochemistry

W Tomaszewski,J Skubiszewska-Zięba,B Charmas

doi:10.1177/0263617417704297

Abstract

The article presents the application of two sets of Ni-doped carbosils in the solid phase extraction of explosives. The adsorbents were prepared by two different methods. The first set of carbosils was obtained by mechanochemical deposition of potato starch and nickel salt on the surface of silica gel, and subsequent carbonization. The second set of carbosils was obtained from the same precursors and under quite similar conditions, i.e. with the exception of mechanochemical deposition of potato starch replaced by the gelation step. The prepared adsorbents were applied in solid phase extraction of explosive nitrate esters, and nitroaromatics from aqueous solutions. The adsorption and desorption steps were evaluated separately. It was found that textural properties, influenced by carbon deposit and nickel content, have a large impact on the solid phase extraction results. The recovery rates obtained onto carbosils prepared by mechanochemical method are approximately thrice as high as those observed for carbosils prepared by gelation method. It was shown that the composites with moderate nickel content can be used as effective materials for extraction both of aliphatic and aromatic explosives.

Highlights

Carbon-inorganic oxides composites, especially based on silica gels or nanosilicas, have proved their high potential in many applications (Gogotsi and Presser, 2013)
Taking into consideration the IUPAC recommendation, the isotherms observed for both series of carbosils belong to the IV type, but the hysteresis loops belong to the type H3
Two series of the hybrid carbon/silica adsorbents was synthesized by the carbonization of the mixture of starch and silica gel Sipernat 50 doped with nickel salt

Summary

Introduction

Carbon-inorganic oxides composites, especially based on silica gels or nanosilicas (carbosils), have proved their high potential in many applications (Gogotsi and Presser, 2013). The dual surface properties of carbosils are caused by a mosaic-like surface structure, which consists both of a nonpolar carbon deposit and of a polar silica. These hybrids can be used for solid phase extraction (SPE) both of organics (Rudzinski et al, 1995), and inorganic, e.g. toxic metal ions (Seledets et al, 2005). Carbosils proved to be promising materials for SPE of explosives (Tomaszewski and Gun’ko, 2015; Tomaszewski et al, 2015). These preliminary results proved that complex polar/nonpolar surface of carbosils had diversified selectivity towards aliphatic, cyclic or aromatic explosives. The preliminary data concerning these experiments were presented quite recently (Tomaszewski et al, 2016)

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