Fig. 4. A sample of 10 μM myoglobin in 1 mM aqueous ammonium acetate being analyzed by (a) wire-in nanoESI at 40 nL min−1, as well as by the (b) main-channel regime at 5 nL min−1 and (c) sub-channel regime at 0.8 nL min−1 of nested-ESI. Ions of m/z 234, m/z 455 are from solvent background. Higher ionization efficiency and average charge states was obtained in the (b) and (c) while the native formations were preserved.
