On-matrix derivatization for dynamic headspace sampling of nonvolatile surface residues

Area of Science:

• Analytical Chemistry
• Environmental Science
• Forensic Science

Background:

• Traditional sampling methods struggle with nonvolatile residues.
• Field and laboratory emission cell (FLEC) dynamic headspace offers potential for residue analysis.
• On-matrix derivatization can improve analyte stability and volatility.

Purpose of the Study:

• To extend FLEC dynamic headspace technique for nonvolatile residue sampling.
• To investigate on-matrix derivatization for enhancing residue analysis.
• To assess the efficacy of derivatization on various challenging substrates.

Main Methods:

• On-matrix derivatization of nerve agent hydrolysis products (MPA) with diazomethane.
• On-matrix derivatization of amines and thiodiglycol with trifluoroacetic anhydride (TFAA).
• Sampling and analysis using FLEC dynamic headspace technique on glass, painted wallboard, concrete, and carpet.

Main Results:

• Successful derivatization and FLEC sampling of MPA on glass, wallboard, concrete, and carpet.
• Successful derivatization and FLEC sampling of amine and thiodiglycol TFAA derivatives on multiple substrates.
• On-matrix derivatization improved recovery and chromatographic behavior for semi-volatile compounds.

Conclusions:

• On-matrix derivatization coupled with FLEC dynamic headspace is effective for sampling nonvolatile residues.
• This technique overcomes limitations of swipe sampling on difficult surfaces.
• The method shows promise for analyzing a broader range of chemical warfare-associated residues.