Improvements in the vapor-time profile analysis of explosive odorants using solid-phase microextraction

Area of Science:

• Analytical Chemistry
• Forensic Science

Background:

• Characterizing the vapor-time profile of explosive headspace odors is crucial for detection.
• Previous methods using solid-phase microextraction (SPME) faced challenges with reproducibility.

Purpose of the Study:

• To develop a modified SPME approach for improved characterization of explosive headspace vapor-time profiles.
• To enhance the reproducibility of measurements for volatile compounds like 2-ethyl-1-hexanol and cyclohexanone.

Main Methods:

• Utilized solid-phase microextraction (SPME) with the introduction of an externally-sampled internal standard (ESIS).
• Employed gas chromatography/mass spectrometry (GC/MS) for analysis.
• Incorporated stable-isotope-labeled internal standards for improved accuracy.

Main Results:

• Achieved improved measurement reproducibility for 2-ethyl-1-hexanol and cyclohexanone compared to prior studies.
• Demonstrated the advantage of exposing the SPME fiber to the ESIS after analyte sampling.
• Minimized competitive loss of target analytes for high volatility compounds by using ESIS with a retracted SPME fiber, enabling longer sampling times.

Conclusions:

• The modified SPME-ESIS-GC/MS method offers enhanced reproducibility and accuracy for explosives headspace analysis.
• This approach effectively corrects for fiber variability and detector drift.
• The technique is particularly beneficial for analyzing high volatility compounds, allowing for extended sampling durations.