Conducting and characterizing femto flow electrospray ionization.

Femto flow electrospray ionization (ESI) with flow rates ranging from 240 fL min -1 to the low pico level (<10 pL min -1 ) was conducted and measured using a submicron emitter tip and relay ESI configuration. Signature analyte ion current intensities and profiles were observed. The obtained flow rate and ionization current enabled size calculation for initial charged nanodroplets.