282574.fig.004a
(a)
282574.fig.004b
(b)
282574.fig.004c
(c)
Figure 4: Schematic of the (a) thermo-Finnigan LCQ Deca mass spectrometer (on-axis spray), (b) Agilent 6410 Triple Quad LC/MS system (off-axis/orthogonal spray), and (c) Waters Micromass Q-TOF Ultima ESI-MS (z-spray).