Imaging with mass spectrometry: Which ionization technique is best?

Abstract

The use of mass spectrometry (MS) to acquire molecular images of biological tissues and other substrates has developed into an indispensable analytical tool over the past 25 years. Imaging mass spectrometry technologies are widely used today to study the in situ spatial distributions for a variety of analytes. Early MS images were acquired using secondary ion mass spectrometry and matrix‐assisted laser desorption/ionization. Researchers have also designed and developed other ionization techniques in recent years to probe surfaces and generate MS images, including desorption electrospray ionization (DESI), nanoDESI, laser ablation electrospray ionization, and infrared matrix‐assisted laser desorption electrospray ionization. Investigators now have a plethora of ionization techniques to select from when performing imaging mass spectrometry experiments. This brief perspective will highlight the utility and relative figures of merit of these techniques within the context of their use in imaging mass spectrometry.

Oversampling for Enhanced Spatial Resolution of Zebrafish by Top-Hat IR-MALDESI-MSI

“…For instance, secondary ion mass spectrometry (SIMS) employs a primary ion beam that bombards the sample surface to eject secondary ions and has reported spatial resolutions anywhere from <200 nm to 3 μm depending on the type of beam utilized . While offering superior spatial resolution relative to most ionization sources, this is at the expense of sensitivity and fragmentation of ions . Alternatively, softer sources have become popularized for biological studies, as they minimize fragmentation and retain the intact analytes that represents the underlying biology of the sample.…”