Selective extraction of nitroaromatic explosives by using molecularly imprinted silica sorbents

Anal Bioanal Chem. 2011 Jan;399(1):449-58. doi: 10.1007/s00216-010-4346-8. Epub 2010 Nov 7.

Abstract

Two molecularly imprinted silicas (MISs) were synthesized and used as selective sorbents for the extraction of nitroaromatic explosives in post-blast samples. The synthesis of the MISs was carried out with phenyltrimethoxysilane as monomer, 2,4-dinitrotoluene (2,4-DNT) as template and triethoxysilane as cross-linker by a sol-gel approach in two molar ratios: 1/4/20 and 1/4/30 (template/monomer/cross-linker). Non-imprinted silica sorbents were also prepared following the same procedures without introducing the template. An optimized procedure dedicated to the selective treatment of aqueous samples was developed for both MISs for the simultaneous extraction of the template and other nitroaromatic compounds commonly used as explosives. The capacity of the MISs was measured by the extraction of increasing amounts of 2,4-DNT in pure water and is higher than 3.2 mg/g of sorbent for each MIS. For the first time, four nitroaromatic compounds were selectively extracted and determined simultaneously with extraction recoveries higher than 79%. The potential of these sorbents was then highlighted by their use for the clean-up of post-blast samples (motor oil, post-mortem blood, calcined fragments, etc.). The results were compared to those obtained using a conventional sorbent, thus demonstrating the interest of the use of these MISs as selective sorbents.

MeSH terms

  • Adsorption
  • Explosive Agents / chemistry
  • Explosive Agents / isolation & purification*
  • Molecular Imprinting
  • Molecular Structure
  • Nitro Compounds / chemistry
  • Nitro Compounds / isolation & purification*
  • Silicon Dioxide / chemical synthesis
  • Silicon Dioxide / chemistry*
  • Solid Phase Extraction / instrumentation*
  • Solid Phase Extraction / methods

Substances

  • Explosive Agents
  • Nitro Compounds
  • Silicon Dioxide