This theory is also applicable to the ion sources used in other mass spectrometers.

This paper report the design parameters, construction and specificity of a small magnetic mass spectrometer with an EI ion source, a sector magnetic analyser and a Faraday cup ion detector.

Following desalinisation the eluted peptides were further purified by reversed-phase capillary column(150 mm 75 m) and online analysed by the coupled tandem mass spectrometry.