Dc. Gale et Rd. Smith, SMALL-VOLUME AND LOW FLOW-RATE ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY OF AQUEOUS SAMPLES, Rapid communications in mass spectrometry, 7(11), 1993, pp. 1017-1021
A new electrospray ionization source (emitter) has been developed whic
h allows the effective utilization of very small sample volumes at muc
h lower flow rates than previously demonstrated. A small diameter etch
ed-tip capillary has been incorporated into a pressure-infusion electr
ospray ionization source. The ability to electrospray aqueous solution
s without the use of an ancillary sheath flow is demonstrated with sev
eral biopolymers. High signal intensities and stable signals are obser
ved for this source in a comparison with a standard methanol-sheath so
urce.