Abstract: A detector system comprises a first analytical stage configured to isolate ions from a sample, a field induced fragmentation stage configured to fragment the ions, a second analytical stage configured to characterize the ions, and at least one detector. The first analytical stage and the second analytical stage each comprise a differential mobility spectrometer. The field induced fragmentation stage comprises strips configured to create an electric field therebetween. In certain embodiments, the system further comprises a port configured between the first analytical stage and the field induced fragmentation stage, configured to introduce a reagent.

Abstract: A method for differential mobility separation of ions using digital-drive based high voltage fast switching electronics. The digital waveform delivered to the spectrometer is characterized by at least two substantially rectangular pulses of different amplitude and polarity. The control circuitry allows for waveform frequency, duty cycle and pulse amplitudes to be varied independently. Balanced as well as unbalanced asymmetric waveforms can be designed for optimum differential mobility separation of ions. The digital drive is designed for differential mobility spectrometers including parallel plate and segmented plate multipoles of planar symmetry, as well as multipoles of cylindrical symmetry, which may optionally be arranged in series. The use of the digital drive establishes alternating electric fields during which the displacement as a result of ion oscillation is determined by mobility coefficients.