Real-Time Monitoring of the Evaporation and Fission of Electrospray-Ionized Polystyrene Beads and Bacterial Pellets at Elevated Temperatures

Anal Chem. 2024 May 7;96(18):7179-7186. doi: 10.1021/acs.analchem.4c00763. Epub 2024 Apr 25.

Abstract

This study uses real-time monitoring, at microsecond time scales, with a charge-sensing particle detector to investigate the evaporation and fission processes of methanol/micrometer-sized polystyrene beads (PS beads) droplets and bacterial particles droplets generated via electrospray ionization (ESI) under elevated temperatures. By incrementally raising capillary temperatures, the solvent, such as methanol on 0.75 μm PS beads, experiences partial evaporation. Further temperature increase induces fission, and methanol molecules continue to evaporate until PS ions are detected after this range. Similar partial evaporation is observed on 3 μm PS beads. However, the shorter period of the fission temperature range is necessary compared to 0.75 μm PS beads. For the spherical-shaped bacterium, Staphylococcus aureus, the desolvation process shows a similar fission period as compared to 0.75 μm PS beads. Comparably, the rod-shaped bacteria, Escherichia coli EC11303, and E. coli strain W have shorter fission periods than S. aureus. This research provides insights into the evaporation and fission mechanisms of ESI droplets containing different sizes and shapes of micrometer-sized particles, contributing to a better understanding of gaseous macroion formation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Escherichia coli* / chemistry
  • Methanol / chemistry
  • Microspheres
  • Particle Size
  • Polystyrenes* / chemistry
  • Spectrometry, Mass, Electrospray Ionization*
  • Staphylococcus aureus*
  • Temperature
  • Volatilization

Substances

  • Polystyrenes
  • Methanol