Chemical Sciences: A Manual for CSIR-UGC National Eligibility Test for Lectureship and JRF/Probe electrospray ionization

Probe electrospray ionization (PESI) is a modified version of conventional electrospray ionization (ESI), where the capillary for sample solution transferring is replaced by a solid needle with a sharp tip. PESI was first introduced by Kenzo Hiraoka et al. in 2007. Compared with conventional electrospray ionization, high salt tolerance and direct sampling and low sample consumption can be found with PESI. Of course, PESI is not a continuous process at all. Normally, the needle for sampling and spraying can be driven up and down under a frequency of 3-5 Hz.