Detection of Triacetone Triperoxide by High Kinetic Energy Ion Mobility Spectrometry

Area of Science:

• Analytical Chemistry
• Spectrometry
• Trace Gas Analysis

Background:

• High Kinetic Energy Ion Mobility Spectrometry (HiKE-IMS) is a low-effort technique for detecting gaseous molecules in complex environments.
• Operating at reduced pressures (10-60 mbar) minimizes ion-neutral collisions, reducing cross-sensitivities and eliminating the need for prior separation.
• HiKE-IMS allows operation over a wide range of electric field strengths (E/N up to 120 Td), enabling separation based on low-field mobility and field-dependent mobility.

Purpose of the Study:

• To employ HiKE-IMS for the detection of triacetone triperoxide (TATP).
• To explore TATP ionization pathways and field-dependent ion mobilities.
• To establish a database of TATP ion mobilities as a function of E/N for reliable detection.

Main Methods:

• Utilized High Kinetic Energy Ion Mobility Spectrometry (HiKE-IMS) for TATP analysis.
• Investigated TATP ionization using different primary reactant ions (H3O+ and NH4+).
• Measured ion mobilities across a range of reduced electric field strengths (E/N).

Main Results:

• Proton transfer ionization with H3O+ resulted in TATP fragmentation.
• Using NH4+ as the reactant ion produced a TATP·NH4+ adduct, which fragmented at high E/N.
• A unique fingerprint of TATP was generated, comprising various ion species and their field-dependent mobilities.

Conclusions:

• HiKE-IMS provides a versatile platform for trace gas analysis, including sensitive TATP detection.
• The field-dependent fragmentation of the TATP·NH4+ adduct offers additional data for reliable identification.
• Operating HiKE-IMS at variable E/N can significantly reduce false positive rates in TATP detection.