State-of-the-art Capillary Electrophoresis Mass Spectrometry Methods for Analyzing the Polar Metabolome
Coupling capillary electrophoresis (CE) to mass spectrometry (MS) provides a powerful approach to profile polar metabolites from biological samples. In particular, the high separation capacity of CE in conjunction with the high specificity of MS allows for hundreds to thousands of electrophoretic peaks to be discriminated by their unique mass-to-charge values. This chapter provides an overview of coupling CE to MS for analyzing polar metabolites, including methods of CE sample injection, common CE–MS interfaces, considerations for selecting an appropriate mass spectrometer, and sample preparation methods. We cover recent studies published in 2013 or later that employ CE–MS to screen for polar metabolites in urine, plasma, serum, cell and tissue extracts. In addition, we cover recent CE–MS methods that analyze minute samples such as single cells, where the limited sample material requires extraordinary strategies. Overall, this work displays the current state-of-the-art for CE–MS based polar metabolomics, including current biological information that can be gained, and outlines future developments that will allow CE–MS based polar metabolomics to flourish.