Nonconductive samples

The effective hyperfine field at the iron nuclei of a paramagnetic nonconducting sample in an external field //ext may be estimated as //ext... 

Direct bulk trace analysis of both conducting and nonconducting sample materials (more problematic)... 

Analysis of Nonconductive Sample Types by Glow Discharge Mass Spectrometry... 

This chapter deals exclusively with the methods that have been developed for the direct solids analysis of nonconductive samples by glow discharge mass spectrometry. The basic approaches to operation and sample preparation for the three primary methodologies of compaction, secondary cathode, and radio frequency powering are described. Examples of source performance and practical applications of each are taken from the analytical literature. Whereas this chapter de-... 

Figure 3 Schematic representation (not to scale) of the source assembly used in the secondary cathode approach to glow discharge mass spectrometry (GD-MS) analysis of nonconductive samples. (From Ref. 21.)...

Pulsed discharges may be utilized to analyze nonconductive samples. Steiner et al. described the use of a pin-type pulsed rf-GD in conjunction with a linear orthogonal extraction TOF-MS [58]. Figure 12.24 depicts differences in the spectra obtained 4.0 msec after the power plateau and 7.0 msec after the plateau. As expected, the sputtered species (Si) in the discharge are found in the afterpeak at 7.0 msec (see Fig. 12.24). The resolution and sensitivity of this early system were limited and improvements were planned in the input optical system of the instrument. 

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