Multi-needle multi-parallel nanospray ionization source for mass spectrometry

An electrospray ion source for a mass spectrometer for generating ions of an analyte from a sample comprising the analyte dissolved in a liquid solvent, said electrospray ion source comprising:

• an electrode receiving the sample and comprising at least a first plurality of protrusions protruding from a base, each protrusion of the at least a first plurality of protrusions having a respective tip
• an extractor electrode spaced at a distance from the electrode so as to form a gap therebetween;
• and
• a voltage source,
• wherein, in operation of the electrospray ion source, the sample is caused to move, in the presence of a gas or air, from the base to each protrusion tip along a respective protrusion exterior so as to form a respective stream of charged particles emitted towards an ion inlet aperture of the mass spectrometer under application of an electrical potential difference between the electrode and the extractor electrode applied by the voltage source.