The present invention relates to an ionization source having a chamber for
ionizing a sample. The ionization chamber has surfaces to reduce the
overall interaction with reactive samples. The inner surface walls of the
ionization chamber or the ionization chamber may be formed from an inert
super alloy. For instance, Inconel.TM. 625, Inconel.TM. 601 or
Hastelloy.RTM. may comprise the ionization chamber or the surface walls
of the ionization chamber. The invention also includes a method for
reducing the interaction of a reactive analyte with an ion source.