Figure 1.
(a) Positive nESI of a solution of bovine CA II in 5 mM NH4 OAc (AA) solution, sprayed out of a theta tip with no electroosmosis. Mass spectra of the same CA II solution after electroosmosis via 100 ms of a 10 Hz square wave at (b) +/−200 V and (c) +/−230 V. The circles at the right of the spectra indicate the theta tip schematic; an aliquot of the same sample was loaded in each channel, and the lightning bolts depict the voltage applied to each side