Matrix-assisted laser desorption/ionization chemical images

The second advantage is the possibility of performing chemical imaging analyses. Even if other techniques, such as matrix-assisted laser desorption/ionization, also allow images to be acquired, ToF-SIMS is, for now, the mass spectrometric technique with the best spatial resolution performance. 

Solid samples can be analyzed by mass spectrometry with techniques providing ionization by desorption (13) such as MALDI (matrix assisted laser desorption ionization) (14) and S-SIMS (static-secondary ion mass spectrometry) (15). Ions are produced by energy deposition on the sample surface. The analysis can be performed at the bead level. Most of all, chemical images can be produced to localize specific compounds on the studied surfaces. 

Today, two-dimensional mass spectrometry analysis of biological tissues by means of a technique called mass imaging, mass spectrometry imaging (MSI), or imaging mass spectrometry has been used in mapping the distribution of elements or chemical groups in samples. Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), secondary ion mass spectrometry (SIMS), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) are three commonly used MSI techniques. 

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