The electrospray ionization–ion mobility spectrometer
(ESI–IMS) was designed and constructed in our group at Isfahan
University of Technology [24]. In summary, it consists of
the IMS cell, the electrospray needle, two high voltage power
supplies, a pulse generator, an analog to digital converter and a
computer that briefly would be explained. The IMS cell length
was divided into two sections: desolvation region (6 cm) and drift
region (13 cm). These two parts separated by a Bradbury–Nielsen
ion gate, made of two series of parallel wires biased to a potential
for blocking ion passage to the drift tube