Nanomechanical sampling of material for nanoscale mass spectrometry chemical analysis

Olga S. Ovchinnikova*, Matthias Lorenz, Ryan B. Wagner, Ron M. A. Heeren, Roger Proksch

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

The ability to spatially resolve the chemical distribution of compounds on a surface is important in many applications ranging from biological to material science. To this extent, we have recently introduced a hybrid atomic force microscopy (AFM)-mass spectrometry (MS) system for direct thermal desorption and pyrolysis of material with nanoscale chemical resolution. However, spatially resolved direct surface heating using local thermal desorption becomes challenging on material surfaces with low melting points, because the material will undergo a melting phase transition due to heat dissipation prior to onset of thermal desorption. Therefore, we developed an approach using mechanical sampling and collection of surface materials on an AFM cantilever probe tip for real-time analysis directly from the AFM tip. This approach allows for material to be concentrated directly onto the probe for subsequent MS analysis. We evaluate the performance metrics of the technique and demonstrate localized MS sampling from a candelilla wax matrix containing UV stabilizers avobenzone and oxinoxate from areas down to 250 nm x 250 nm. Overall, this approach removes heat dissipation into the bulk material allowing for a faster desorption and concentration of the gas phase analyte from a single heating pulse enabling higher signal levels from a given amount of material in a single sampling spot.

Original languageEnglish
Pages (from-to)2747-2754
Number of pages8
JournalAnalytical and Bioanalytical Chemistry
Volume413
Issue number10
Early online date6 Oct 2020
DOIs
Publication statusPublished - Apr 2021

Keywords

  • Mechanical sampling
  • Thermal desorption
  • Nanometer scale
  • Atmospheric pressure
  • Atomic force microscopy
  • Mass spectrometry
  • Atmospheric pressure chemical ionization
  • MICRO-THERMAL ANALYSIS
  • ATOMIC-FORCE MICROSCOPY
  • DESORPTION
  • RESOLUTION

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