Application of Acoustic Ejection Mass Spectrometry to Accelerate Drug Discovery

Acoustic ejection mass spectrometry (AEMS) combines acoustic droplet ejection (ADE), an open‐port interface (OPI), and electrospray ionization mass spectrometry (ESI‐MS) to deliver a high‐speed, label‐free analytical platform tailored to drug discovery workflows. ADE transfers nanoliter droplets in a contactless, precise manner; OPI enables rapid on‐the‐fly dilution and sample handling; and modern ESI‐MS provides sensitive, broad‐coverage detection. Together, these elements remove much of the sample preparation and complex method development required by traditional approaches, enabling rapid sampling and high data quality. This review outlines the working principles of AEMS and summarizes method development strategies and representative applications in high‐throughput screening (HTS) for hit identification, compound quality control (QC), high‐throughput experimentation (HTE), process chemistry, ADME profiling, and bioanalysis. Key advances in instrumentation, automation, and data processing, as well as future perspectives, are also discussed.