Droplet-based extraction mass spectrometry

Analytical methods based on microdroplet technology have made great progress in life science research. As a new method of sample separation and enrichment, single-drop extraction has been applied in the pretreatment of chromatographic samples. Recently, the combination of microdroplet technology and mass spectrometric detection technology has become a new direction. The microdroplet extraction mass spectrometry surface analysis technology utilizes a trace amount of solvent on a sample surface in the form of a single droplet that extracts the analyte and uses a chip nozzle to analyze the extract via nanoliter electrospray ionization mass spectrometry (MS). Microdroplet extraction single-cell mass spectrometry has facilitated an important research direction in single-cell mass spectrometry. In this review, we focus on the method of droplet extraction at tissue and cellular levels: liquid extraction surface analysis (LESA) was introduced at the tissue level; single-cell droplet microextraction technology was presented at the cell level. •The combination of droplet microextraction and mass spectrometry provides convenience for the study of omics.•Liquid extraction surface analysis (LESA) is a typical method of droplet microextraction at tissue level.•DESI, nanoDESI, and MasSpec Pen are important droplet microextraction based tissue analysis techniques.•Some single-cell level droplet microextraction methods have been developed.