Increasing the resolution of ion mobility increment spectrometers using the ripple voltage

Abstract

A new method is proposed and verified, according to which the resolving power of an ion mobility increment spectrometer (IMIS) can be increased by applying a voltage of certain fixed frequency (ripple voltage) to the output electrode. The results of computer simulations and the experiment showed that this method leads to narrowing of the interval of compensating voltages for which ions can be transmitted via the IMIS, which improves the resolution at the expense of a decrease in the signal intensity. For protonated diethylamine ions, the proposed method provides for a more than twofold improvement of the resolution at a 40% decrease in the signal intensity. The application of a ripple voltage to the output electrode retains low diffuse losses of ions in the analytical gap.