Electric modeling and characterization of pulsed high‐voltage nanoelectrospray ionization sources by a miniature ion trap mass spectrometer

Abstract

A better understanding of nanoelectrospray ionization (nano‐ESI) would be beneficial in further improving the performances of nano‐ESI. In this work, the pulsed high‐voltage (HV) nano‐ESI has been electrically modeled and then systematically characterized by both voltage‐current and mass spectrometry measurements. First, the equivalent resistance of a nano‐ESI source changes with respect to both emitter tip diameter and the HV applied. Increased voltage could improve both spray current and ionization efficiency of the pulsed HV nano‐ESI. Compared with conventional DC HV method, a pulsed HV has less heating effect on the capillary tip and thus allowing the application of a much higher voltage onto a nano‐ESI source. As a result, a pulsed HV nano‐ESI could further boost the ionization efficiency of nano‐ESI by employing even higher voltages than conventional DC nano‐ESI sources.

Pulsed Nano-ESI: Application in Ion Mobility-MS and Insights into Spray Dynamics

“…11,12 Furthermore, the short duration of applied voltage reduces ESI-induced electrochemical reactions of the analyte. 13 Moreover, enhanced resistance to emitter tip clogging 14 and reduced emitter tip damage from corona discharge 15 have been reported for nano-ESI operated in pulsed mode.…”

“…For example, higher sensitivities and improved signal-to-noise ratios have been observed for a pulsed nano-ESI relative to a continuous nano-ESI source. , Furthermore, the short duration of applied voltage reduces ESI-induced electrochemical reactions of the analyte . Moreover, enhanced resistance to emitter tip clogging and reduced emitter tip damage from corona discharge have been reported for nano-ESI operated in pulsed mode.…”

Triboelectric Nanogenerators for the Masses: A Low-Cost Do-It-Yourself Pulsed Ion Source for Sample-Limited Applications

“…4 In addition, these pulsed techniques reduce emitter heating, allowing for higher voltages to be applied while decreasing the chances of clogging. 5 Triboelectric nanogenerators (TENG) are intrinsically pulsed voltage generators 6 and have been previously deployed to improve upon DC nESI approaches. 7−9 TENG provide voltage to the nESI emitter by harvesting triboelectricity, the electrical potential generated when rubbing dissimilar materials against one another.…”

Perturbation-induced high-frequency pulsing of nano-ESI with facile ion selection at atmospheric pressure

“…6,7,10,16 Moreover, heating of the emitter tip, deformation by electrical discharge, and clogging of the emitter are minimized in pulsed mode, facilitating the long-term use of nano-ESI tips. 7,17 Importantly, pulsed nano-ESI has also shown promise in enhancing ionization. In one study comparing continuous nano-ESI operated at 150 nL/min to 20 Hz pulsed operation of the same source, 3.6 fold higher protonated reserpine intensities were detected in the pulsed mode.…”