Suppression of collision-induced dissociation in a supersonically expanding gas

TL;DR

This study shows that supersonic gas expansion in electrospray ionization sources reduces collision-induced dissociation, improving ion stability and transmission in high-resolution mass spectrometry.

Contribution

It reveals the impact of gas-flow dynamics on ion fragmentation, demonstrating suppression of dissociation due to supersonic expansion effects.

Findings

Supersonic gas expansion decreases ion internal energy increase.

Reduced ion fragmentation observed with supersonic expansion.

Implications for improved ion transmission in mass spectrometry.

Abstract

In high-resolution mass spectrometry, an electrospray ionization source is often paired with an ion-funnel to enhance ion transmission. Although it is established that ions experience collision-induced dissociation as they pass through this device, the impact of gas-flow dynamics on ion fragmentation remains unexplored. The present work demonstrates that the gas-flow dynamics from the capillary interface of an electrospray ionization source into an ion-funnel significantly reduces ion fragmentation. This reduction stems from the substantial decrease in the rate of increase in the internal energy of the ions resulting from the collisions with a supersonically expanding gas. The results of this study have significant consequences for systems that employ electrospray mass spectrometry and ion-mobility spectrometry.