Trace Analysis of Nonconducting Materials by a Spark Source Mass Spectrographic Auxiliary Electrode Method

The survey analysis capabilities of spark source mass spectrography have proved to be very important in the determination of very low concentrations of elements in nonconductors and semiconductors. Some of the methods devised for the special handling and sparking of the poor conductors have been reviewed by Guthrie¹. In general, attempts to initiate and sustain a radio frequency spark between nonconductor self-electrodes require inconviently high spark voltages and considerable operator time and attention. Moreover, the low ion yields often characteristic of the nonconductor self-electrode spark compel exposure times commonly in excess of one hour for exposure levels requisite for the detection of impurities at 1 part-per-million concentrations.