Electrospray Post-Ionization Mass Spectrometry of Electrosurgical Aerosols

Abstract

The feasibility of electrospray (ES) ionization of aerosols generated by electrosurgical disintegration methods was investigated. Although electrosurgery itself was demonstrated to produce gaseous ions, post-ionization methods were implemented to enhance the ion yield, especially in those cases when the ion current produced by the applied electrosurgical method is not sufficient for MS analysis. Post-ionization was implemented by mounting an ES emitter onto a Venturi pump, which is used for ion transfer. The effect of various parameters including geometry, high voltage setting, flow parameters, and solvent composition was investigated in detail. Experimental setups were optimized accordingly. ES post-ionization was found to yield spectra similar to those obtained by the REIMS technique, featuring predominantly lipid-type species. Signal enhancement was 20-to 50-fold compared with electrosurgical disintegration in positive mode, while no improvement was observed in negative mode. ES post-ionization was also demonstrated to allow the detection of non-lipid type species in the electrosurgical aerosol, including drug molecules. Since the tissue specificity of the MS data was preserved in the ES post-ionization setup, feasibility of tissue identification was demonstrated using different electrosurgical methods.

New mass spectrometry techniques for studying physical chemistry of atmospheric heterogeneous processes

“…Guenther et al [94] used a method related to EESI to post-ionise electrosurgical aerosol produced by rapid heating of biological tissues. The electrosurgical aerosol contains a detectable amount of ions, which are dominated by fragments of phospholipids.…”

A comprehensive high-resolution mass spectrometry approach for characterization of metabolites by combination of ambient ionization, chromatography and imaging methods

“…Therefore, modifications of the method such as desorption from activated surfaces (desorption ionization on silicon, DIOS) or post‐ionization of the desorbed molecules by a second ionization method have been applied to increase the ion yield in laser‐based ionization methods. Electrospray ionization is the most commonly used post‐ionization method, but laser ionization and corona discharge ionization have also shown to improve ion signal intensity. Laser desorption followed by electrospray post‐ionization has been performed with ultraviolet (UV) lasers (electrospray‐assisted laser desorption ionization, ELDI) and infrared (IR) lasers (laser ablation electrospray ionization, LAESI) in the past.…”

“…The employed ion source is a combination of two previously published systems. The post‐ionization and the ion transfer system were described in a study on surgical aersols . In analogy to a previous study on LDI, a UV laser (355 nm) was used for desorption in our experiments.…”

Optimized Mass Spectrometry Analysis Workflow with Polarimetric Guidance for ex vivo and in situ Sampling of Biological Tissues

“…This workflow is used to examine the surface of thick tissue ex viv o, and extends the pioneering works of the Takats group in rapid tissue profiling with surgical aerosols produced with diathermy, lasers and ultrasonic aspiration methods 2, 12–14 . Unlike electrocautery approaches that produce aerosolized tissue material for real time capture and MS analysis 2, 9, 16 PIRL uses a “cold” ablation laser that does not thermally damage tissue surrounding the sampling site, with minimal amounts of post ablation scar tissue and avoidance of the cellular stress response 30 .…”