Vapor Exposure for Tuning Charge State Distributions of Electrosprayed Proteins with an Agilent Jet Stream source. Insights from Fluorescence spectroscopy

摘要

1. pH changes due to basic seeded sheath gas mainly occur at the ESI tip exit, and is mainly due to electrochemical effects [6]. 2. Higher pH values can be obtained with a less basic initial solution (pH 7.5) sprayed using basic sheath gas than with a more basic initial solution (pH 8.75) sprayed with pure sheath gas. 3. The pH evolution in the ESI plume obtained using pure and basic seeded sheath gas was correlated with the evolution of the charge state distribution observed in mass spectrometry.