# High-Resolution Microscope-Mode Secondary Ion Mass Spectrometry Imaging

## TL;DR

A new high-resolution SIMS microscope is developed for fast imaging of biological samples, capturing detailed molecular information in mouse brain tissue.

## Contribution

The novel SIMS instrument achieves high mass and spatial resolution using time-of-flight and pulsed ion extraction methods.

## Key findings

- The instrument provides mass resolutions of m/Δm ∼ 6900 with a fast scintillator screen.
- Spatial resolutions better than 5 μm were achieved under optimal conditions.
- Biologically relevant ions like phospholipids and amino acids were captured in mouse brain tissue.

## Abstract

We report the development
of a secondary ion mass spectrometry
(SIMS) microscope-mode imaging instrument suitable for a wide range
of applications in which high throughput is an advantage. By coupling
time-of-flight mass spectrometry with pulsed ion extraction methods,
the instrument can provide mass resolutions of m/Δm ∼ 2000 across a mass range of m/z

≳
1000. We show that the use of an ion imaging
detector with a fast scintillator screen, yielding time-of-flight
time resolutions of a few nanoseconds, improves the mass resolution
further to m/Δm ∼ 6900.
Spatial resolutions of better than 5 μm were also obtained under
optimum conditions. We demonstrate the capability of the instrument
by imaging atomic and molecular ion species in mouse brain tissue
sections, capturing a range of biologically relevant ions, including
phospholipid and amino acid fragments, over millimeter length scales
within minutes.