Article

Exploring the Power of TOF-SIMS by Coupling Collision-Induced Dissociation with Surface-Induced Dissociation for Structural Analysis

Surface Analysis Spotlight: TOF-SIMS

by Jacob Schmidt Staff Scientist

Tandem mass spectrometry (tandem MS, or MS/MS) is a vital tool for the accurate identification of molecules and is frequently used in a broad range of applications including single cell-omics, metabolomics, natural product chemistry, pharmaceutical research, high-performance polymers and composites, 2D materials, electronic devices, catalysis, forensics, and failure analysis. This technique typically involves collision-induced dissociation (CID) where precursor molecules are fragmented into constituent components at kinetic energies below 200 electron volts (eV). Enhancing the capabilities of traditional tandem MS, kilo-electron volt CID (keV-CID) enables the detailed structural elucidation of molecules, metabolites, and degradation products. This molecular identification tool can be extended to mass spectrometry imaging (MSI), allowing for 2D and 3D molecular visualization.

In this presentation we will introduce Surface Induced Dissociation (SID) as a complimentary tool to CID. Unlike CID, which promotes cleavage at every molecular bond, SID is more subtle, leading to the observation of functional group chemistry. Although both SID and CID spectra are generated at the same kinetic energy, the molecular energetics and relaxation pathways are distinct, which can significantly impact spectral calibration and the identification of precursor peaks. An example of the utility of SID is shown in Figure 1, where the subtle fragmentation of an adduct ion prevents covalent bond breakage and shows fragmentation of only the adducted potassium ion.

	Figure 1 - Tandem MS spectra of a rubr(e/y)nolide precursor found in Sextonia rubra wood showing the extensive bond breakage due to keV-CID fragmentation on top, and the solitary fragmentation of the potassium adduct from SID on the bottom.

For more information on how tandem MS can be used in surface analysis, please attend the upcoming talk at ECASIA 24 where Dr. Jacob Schmidt will discuss the " Exploring the Power of TOF-SIMS by Coupling Collision-Induced Dissociation with Surface-Induced Dissociation for Structural Analysis."