The invention provides devices, device configurations and methods for improved sensitivity, detection level and efficiency in mass spectrometry particularly as applied to biological molecules, including biological polymers, such as proteins and nucleic acids. In one aspect, the invention relates to charged droplet sources and their use as ion sources and as components in ion sources. In another aspect, the invention relates to charged droplet traps and their use as ion sources and as elements of ion sources. Further, the invention relates to the use of aerodynamic lenses for high efficiency ion transport to a charge particle analyzer, particularly a mass analyzer. Devices of this invention allow mass spectral analysis of a single charged droplet. The ion sources of this invention can be combined with any charge particle detector or mass analyzer, but are a particularly benefit when used in combination with a time of flight mass spectrometer.