ABSTRACT
In quantitative mass spectrometry imaging (Q-MSI) experiments, one or more standards are either deposited directly onto the sample or delivered to the sample via the extraction solvent. This chapter provides a detailed summary of these approaches and highlights some of the key applications of Q-MSI in biological research. Q-MSI is a rapidly growing field poised to transform mass spectrometry imaging (MSI) into an analytical technique that will enable accurate measurement of chemical gradients of hundreds of molecules in biological samples. Q-MSI experiments rely on the assumption that signal intensities in mass spectra obtained in individual pixels are proportional to analyte concentrations at each location. Relative Q-MSI typically refers to an experiment, where the absolute ion intensity of a compound of interest in each pixel of the ion image is converted into the relative abundance of the compound. Further development and validation of Q-MSI are needed to ensure its accuracy, robust operation, and applicability to a broad range of compounds.
