Fig. 6.

Analysis of ion suppression by phosphatidylcholine. A: Ion suppression by components of Surfacten was analyzed by postcolumn infusion of mSP-C. Blank or Surfacten is injected into the LC while measuring signals of the infused mSP-C. Interfering compounds eluted from the column after Surfacten injection cause ion suppression, which can be detected by comparing the mSP-C signals with those of a blank injection. B: The signals are percent of those when a blank sample was injected into the column. Elution pattern of DPPC is overlaid in gray. C, D: Retention times of mSP-C (C) and bSP-C (D) with different palmitoylation status are compared with that of DPPC (overlaid in gray).