This invention provides a method of aligning a nanospray capillary needle, a set of electrodes, and a capillary input to a mass spectrometer. The electrode system is formed using microengineering technologies, as an assembly of two separate chips. Each chip is formed on an insulating plastic substrate. The first chip carries mechanical alignment features for the capillary electrospray needle and the API mass spectrometer input, together with a set of partial electrodes. The second chip carries a set of partial electrodes. The complete electrode system is formed when the chips are assembled in a stacked configuration, and consists of an einzel lens capable of initiating a Taylor cone and separating ions from neutrals by focusing.