Study of experimental variability in TOF-SIMS mass spectrometry imaging of biological samples

Studies of the chemical composition of organs using mass spectrometry imaging become an important issue to better understand the mechanisms involved in various diseases. Biologists not only focus on the detection and characterization of compounds of interest but also on the reliability of the method. Time-of-flight secondary ion mass spectrometry (TOF-SIMS), which is already known to offer an excellent repeatability in material sciences, is also a method of choice for the detection and mapping of small molecules in biological samples. Ions corresponding to different types of lipids such as the fatty acid chains, cholesterol and vitamin E were studied in gyrus dentatus and cortex of rat brain sections. The analysis of the repeatability of the data was conducted, and a global coefficient of variation of about 10% was found. It thus confirms that TOF-SIMS studies can be considered as an accurate analytical method for the study of biological samples.