Microdroplet mass spectrometry: Accelerating reaction and application

• Published in: Electrophoresis Vol. 43; no. 1-2; pp. 74 - 81
• Main Authors: Kafeenah, Husam, Jen, Hung‐Hsiang, Chen, Shu‐Hui
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2022
• Subjects: Chemical reactions; Coupling (molecular); Desorption electrospray ionization; Electrospray ionization; Electrospraying; Ionization; Ions; Laser ablation; Mass spectrometry; Microdroplet chemistry; Proteins; Scientific imaging; Spectrometry, Mass, Electrospray Ionization; Spectroscopy; Microdroplet chemistry; Desorption electrospray ionization; Mass spectrometry; Electrospray ionization
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/elps.202100208

Electrospray ionization (ESI) and desorption electrospray ionization (DESI) are common soft ionization method of mass spectrometry (MS). However, recent studies revealed that some chemical reactions can be induced or greatly accelerated in the sprayed microdroplets compared to the same reaction in the bulk. These open a new area in using microdroplet MS to explore new chemistry and develop new applications. This minireview will introduce microdroplet chemistries and explore various microdroplet techniques most of which are ESI‐ or DESI‐based extensions by incorporating transfer tube, supersonic nebulizing gas, droplet fusion, spray extraction, laser irradiation, or laser ablation for online/offline MS analysis. Potential applications associated with new techniques, including real‐time reaction monitoring, high‐throughput reaction screening, protein identification, and protein characterization, are also described. Future outlook, such as coupling microdroplet MS with separation techniques, is proposed and discussed.