LAUSR

The online coupling of microchip electrophoresis (ME) as a fast, highly efficient, and low‐cost miniaturized separation technique to mass spectrometry (MS) as an information‐rich and sensitive characterization technique results in ME–MS an attractive tool for various applications. In this paper, we review the basic concepts and latest advances in technology for ME coupled to MS during the period of 2016–2021, covering microchip materials, structures, fabrication techniques, and interfacing to electrospray ionization (ESI)–MS and matrix‐assisted laser desorption/ionization–MS. Two critical issues in coupling ME and ESI–MS include the electrical connection used to define the electrophoretic field strength along the separation channel and the generation of the electrospray for MS detection, as well as, a miniaturized ESI‐tip. The recent commercialization of ME–MS in zone electrophoresis and isoelectric focusing modes has led to the widespread application of these techniques in academia and industry. Here we summarize recent applications of ME–MS for the separation and detection of antibodies, proteins, peptides, carbohydrates, metabolites, and so on. Throughout the paper these applications are discussed in the context of benefits and limitations of ME–MS in comparison to alternative techniques.