High-resolution separations and improved ion production and transmission in metabolomics

The goal of metabolomics analyses is detection and quantitation of as many sample components as reasonably possible in order to identify compounds or “features” that can be used to characterize the samples under study. When utilizing electrospray ionization to produce ions for analysis by mass spectrometry (MS), it is important that sample constituents are efficiently separated prior to ion production, in order to reduce complexity and minimize ionization suppression and thereby extend the dynamic range of the measurement, as well as the coverage of the metabolome. Similarly, optimization of the MS inlet and interface can lead to increased measurement sensitivity. This review focuses on the role of high-resolution liquid chromatography (LC) separations in conjunction with improved ion production and transmission for LC-MS-based metabolomics. We place additional emphasis on the compromise between metabolome coverage and sample-analysis throughput.