The use of mass defect in modern mass spectrometry

Abstract

Mass defect between a compound's exact mass and its nominal mass is being increasingly used in modern mass spectrometry. This is mainly due to the growing use of high resolution mass spectrometers capable of exact mass measurements. Filtering based on known mass defects allows the selective profi ling of specifi c compound classes. Mass defect fi ltering has become so important that automated mass defect data processing tools are currently incorporated in all high resolution MS platforms. This approach is applicable to many areas in analytical and bioanalytical chemistry. In this tutorial special feature article, Lekha Sleno (Assistant Professor at the Université du Québec à Montréal) describes the principle of the use of mass defect and the various mass defect fi ltering tools in diff erent applications in environmental and life sciences. Prof. Sleno's research interests include the study of reactive metabolites and the bonds they form with proteins, and the characterization and quantifi cation of endogenous metabolites. She is considered to be one of the rising stars of the Canadian mass spectrometry scene.