Detection of Triacetone Triperoxide by High Kinetic Energy Ion Mobility Spectrometry.

High Kinetic Energy Ion Mobility Spectrometry (HiKE-IMS) is a versatile technique for the detection of gaseous target molecules that is particularly useful in complex chemical environments, while the instrumental effort is low. Operating HiKE-IMS at reduced pressures from 10 to 60 mbar results in fewer ion-neutral collisions than at ambient pressure, reducing chemical cross-sensitivities and eliminating the need for a preceding separation dimension, e.g., by gas chromatography. In addition, HiKE-IMS allows operation over a wide range of reduced electric field strengths / up to 120 Td, allowing separation of ions by low-field ion mobility and exploiting the field dependence of ion mobility, potentially allowing separation of ion species at high / despite similar low-field ion mobilities. Given these advantages, HiKE-IMS can be a useful tool for trace gas analysis such as triacetone triperoxide (TATP) detection. In this study, we employed HiKE-IMS to detect TATP. We explore the ionization of TATP and the field-dependent ion mobilities, providing a database of the ion mobilities depending on /. Confirming the literature results, ionization of TATP by proton transfer with HO in HiKE-IMS generates fragments, but using NH as the primary reactant ion leads to the TATP·NH adduct. This adduct fragments at high /, which could provide additional information for reliable detection of TATP. Thus, operating HiKE-IMS at variable / in the drift region generates a unique fingerprint of TATP made of all ion species related to TATP and their ion mobilities depending on /, potentially reducing the rate of false positives.