Sputter-Coated Metal Screening for Small Molecule Analysis and High-Spatial Resolution Imaging in Laser Desorption Ionization Mass Spectrometry.
Rebecca L HansenMaria Emilia DueñasYoung-Jin LeePublished in: Journal of the American Society for Mass Spectrometry (2018)
Nanoparticles are efficient matrices in laser desorption/ionization (LDI) mass spectrometry (MS), especially for the profiling or imaging of small molecules. Recently, solvent-free physical vapor desorption (PVD), or sputter coating, was adopted as a homogenous method to rapidly apply metal nanoparticles (NPs) in situ to samples prior to LDI MS or MS imaging analysis. However, there has been no systematic study comparing different metal targets for the analysis of a variety of small molecule metabolites. Here, we present a screening and optimization of various sputter-coated metals, including Ag, Au, Cu, Pt, Ni, and Ti, for LDI analysis of small molecules in both positive and negative ion modes. Optimized sputter coating is then applied to high-spatial resolution LDI mass spectrometry imaging (MSI) of maize root and seed cross-sections. Noble metals, Ag, Au, and Pt, are found to be much more efficient than transition metals and organic matrices for most small metabolites. Sputter-coated metals are efficient for neutral lipids, such as triacylglycerols and diacylglycerols, but are very inefficient for most phospholipids. Graphical Abstract ᅟ.
Keyphrases
- mass spectrometry
- high resolution
- small molecule
- liquid chromatography
- ms ms
- multiple sclerosis
- capillary electrophoresis
- gas chromatography
- health risk
- high performance liquid chromatography
- health risk assessment
- sensitive detection
- physical activity
- single cell
- single molecule
- quantum dots
- climate change
- fatty acid
- fluorescence imaging
- gold nanoparticles
- highly efficient