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Figure 9.2
The Plasma Desorption Ionization System
It might be possible however, to use an aluminum sheet as a transport medium, and store the eluted
solutes on it in the form of a chromatographic memory. The sheet could then be scanned in the plasma
desorption interface off-line.
The Inductively Coupled Plasma Ionization Source
The inductively coupled plasma ionization source is very similar to the ICP torch that has been
described previously. The eluent is first nebulized and the atomized eluent passes through a spray
chamber and then enters the ICP torch. The gas and ions leaving the jet first enter an expansion
chamber through a cooled sampling cone with an orifice, about 1 mm in diameter, where the gas
expands and is pumped away. A portion of the jet from the torch then passes through a second orifice
called the skimmer cone. The ICP produces singly-charged positive ions for most elements which
makes it a very efficient source for coupling to a mass spectrometer. A series of electrostatic lenses
focus the ions into the
