Cavitand-based solid-phase microextraction coating for the selective detection of nitroaromatic explosives in air and...

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Nitroaromatic compounds are common explosives and taggants requiring sensitive detection methods.
• Current methods for detecting trace explosives in environmental samples can be limited in selectivity and sensitivity.
• Solid-phase microextraction (SPME) offers a solvent-free approach for sample preparation and analyte enrichment.

Purpose of the Study:

• To develop a selective cavitand-based solid-phase microextraction (SPME) coating for the determination of nitroaromatic explosives and taggants.
• To enhance the selectivity of the SPME coating towards nitro group-containing analytes.
• To evaluate the performance of the developed coating for trace level detection in air and soil samples.

Main Methods:

• Synthesis of a quinoxaline cavitand functionalized with a carboxylic group.
• Fabrication of SPME fibers coated with the synthesized cavitand.
• Characterization of the coating's physical and chemical properties (thickness, morphology, thermal stability, pH resistance).
• Evaluation of the SPME method's performance for the determination of nitroaromatic explosives in air and soil samples.

Main Results:

• The cavitand-based SPME coating exhibited an average thickness of 50 (±4) μm and thermal stability up to 400 °C.
• Excellent fiber-to-fiber and batch-to-batch repeatability were achieved, with relative standard deviations (RSD) below 4%.
• The developed coating demonstrated selective sampling capabilities, achieving limit of detection (LOD) values in the low parts-per-billion by volume (ppbv) range for air and nanogram per kilogram (ng kg⁻¹) range for soil.

Conclusions:

• A novel cavitand-based SPME coating was successfully synthesized and characterized.
• The developed coating provides selective and sensitive determination of nitroaromatic explosives and taggants at trace levels.
• This method holds significant potential for environmental monitoring and security applications requiring the detection of explosive residues.