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<p> We present an acoustic ejection mass spectrometry (AEMS) setup for ESI-MS based sample </p><p> injection at a sampling rate faster than current ESI and MALDI techniques. A modified acoustic </p><p> droplet ejection system was combined with an open port interface and a modified ESI source. To </p><p> simulate applications of drug metabolism and pharmacokinetics analysis and high-throughput </p><p> screening campaigns, two stress tests were performed regarding ion suppression and system </p><p> endurance in combination with minor sample preparation. Maximum sampling rate was 6 Hz for </p><p> dextromethorphan and d3-dextrorphan (each 100 nM) for 1152 injections in 63 s at FWHM of </p><p> 105 ms and %RSD of 7.7%/7.5% without internal standard correction. Enzyme assay buffer and </p><p> crude dog plasma caused signal suppression of 51%/73% at %RSD of 5.7%/6.7% (n = 120) and </p><p> stable OPI performance during 1100 injections. An endurance buffer revealed minor OPI pollution </p><p> and constant signals for >25.000 injections (%RSD = 8.5%, n = 10,557). </p></div>
Ultra-High-Throughput Acoustic Droplet Ejection-Open Port Interface-Mass Spectrometry for Parallel Medicinal Chemistry