A Modular Variable Temperature FT-IMS Instrument Optimized for Gas-Phase Ion Chemistry Applications

The latest iteration
of modular, open-source rolled ion mobility
spectrometers was characterized and tailored for heated ion chemistry
experiments. Because the nature of ion-neutral interactions is innately
linked to the temperature of the drift cell, heated IMS experiments
explicitly probe the fundamental characteristics of these collisions.
While classic mobility experiments examine ions through inert buffer
gases, doping the drift cell with reactive vapor enables desolvated
chemical reactions to be studied. By using materials with minimal
outgassing and ensuring the isolation of the drift tube from the surrounding
ambient conditions, an open-source drift cell outfitted with heating
components enables investigations of chemical reactions as a function
of temperature. We show here that elevated temperatures facilitate
an increase in deuterium incorporation and allow for hydrogen/deuterium
exchanges otherwise unattainable under ambient conditions. While the
initial fast exchanges get faster as temperature is increased, the
slow rate which rises from the kinetic nonlinearity though to be attributed
to ion-neutral clustering, remains constant with no change in mobility
shifts. Additionally, we show the analytical merit of multiplexing
mobility data by comparing the performance of traditional signal-averaging
and FT-IMS modes.