Separation efficiency of a chemical warfare agent simulant in an atmospheric pressure ion mobility time-of-flight mass spectrometer (IM(tof)MS)

An electrospray ionization atmospheric pressure ion mobility orthogonal reflector time-of-flight mass spectrometer (IM(tof)MS) that routinely achieves mobility and mass separation efficiencies in line with theoretical limits is reported. The maximum IM(tof)MS efficiency for a given instrumental design depends widely upon the various key parameters such as voltage, temperature, initial pulse width, interface and reflectron energies. Optimization of the current IM(tof)MS instrument, resulted in an IMS separation efficiency over 133,000 theoretical plates (a resolving power of 155) and a resolving power of 1200 for the TOFMS using a singly charged G/V-type chemical warfare agent (CWA) nerve simulant (dimethyl methylphosphonate (DMMP)) in less than 12 ms.