(A) Images of nano-ESI emitter tips at conventional 1.6 μm inner diameters and submicron 0.5 μm inner diameters. (B) Mass spectra of AqpZ using 1.6 μm or 0.5 μm tip diameter emitters in ammonium acetate or Tris-NaCl buffer showing greater tolerance to salt buffers with submicron emitters. Adapted from Susa, A. C.; Lippens, J. L.; Xia, Z.; Loo, J. A.; Campuzano, I. D. G.; Williams, E. R. Submicrometer Emitter ESI Tips for Native Mass Spectrometry of Membrane Proteins in Ionic and Nonionic Detergents. J. Am. Soc. Mass Spectrom.
2018, 29, 203–206 (ref 81). Copyright 2018 American Chemical Society.