Rapid MS/MS analysis with Acoustic Ejection Mass Spectrometry (AEMS)

The use of a chromatographic separation technique (such as high pressure liquid chromatography) in line with a mass spectrometer has been the standard approach for quantitative LC-MS analysis since the introduction of commercially available mass spectrometers. Electrospray ionization (ESI) is the most common ionization technique used with LC-MS because of its broad compound coverage and ionization efficiency when compared to other approaches like atmospheric pressure chemical ionization (APCI) or matrix assisted laser desorption ionization (MALDI). Here a newly developed Acoustic Ejection Mass Spectrometry (AEMS) platform - the SCIEX Echo^® MS System - is described for rapid, chromatography-free MS/MS analysis.

High-throughput screening (HTS) assays, which are often used in early stage pharmaceutical research to identify drug candidates from libraries of many thousands of compounds, usually rely on data generated using a plate reader. A key feature of plate readers is that, once the assay is developed, they can be run quickly, generating a numeric readout for each well in an entire plate in less than a minute. But development of the assay can be very time consuming. Also, the actual output is typically based on a reaction generating an absorption or emission that is caused by the compound of interest, not by the compound itself, which can lead to specificity issues and can complicate troubleshooting. The Echo MS System brings the ease of compound tuning, and the specificity of mass spectrometry, into the throughput realm of plate readers, making this technology a viable option for HTS research groups.