Introducing samples directly into electrospray ionization mass spectrometers using a nanospray interface

Electrospray (ES) is a concentration-dependent phenomenon, and operation at high flow rates results in a corresponding high rate of sample consumption. Sensitivity increases are most readily achieved by decreasing the flow rate of sample solution into the electrospray source. In recent years, a number of methodologies have been developed to achieve ES analyses at sub-ml/min flow rates. There are a large number of microscale ES devices currently in use, but this unit describes in detail a micro-scale interface for direct liquid introduction without separation.