AMUSE mass spectra produced by averaging 1.2 sec of data obtained with different devices. (A) 5 μM reserpine on a 5-μm chip, (B) 5 μM reserpine on a 3-μm chip, (C) 10 μM leucine enkephalin on a 5-μm chip, and (D) 5 μM leucine enkephalin on a 3-μm chip. All solutions were prepared using 99.9:0.1 (v:v) water:glacial acetic acid as the solvent. Operating conditions: (A) and (C): 100 VDC, 100 μL min-1 liquid flow rate, 7.5 L min-1 N2, (B) and (D): 100 VDC, 30 μL min-1 liquid flow rate, 9.3 L min-1 N2. The base peak absolute intensity is noted in the upper right corner of each panel.