Glow discharge MS

Tab. 11. Detection limits ( tg/g) for steels in spark and glow discharge OES and glow discharge MS.

The applications discussed are from many forms of atomic MS, including ICP-MS, glow discharge MS (GDMS), and coupled chromatography-lCP-MS. The websites of the major instmment manufacturers (Agilent, LECO, PerkinElmer, Thermo Electron, and Varian, to name a few for ICP-MS) are an excellent source for applications of the techniques. 

Glow discharge is essentially a simple and efficient way to generate atoms. Long known for its ability to convert solid samples into gas-phase atoms, GD techniques provide ground-state atoms for atomic absorption or atomic fluorescence, excited-state atoms for atomic emission, and ionised atoms for MS [158], Commercial instrumentation has been developed for all these methods, except for GD-AFS and pulsed mode GD. 

Table 8.60 shows the main features of GD-MS. Whereas d.c.-GD-MS is commercial, r.f.-GD-MS lacks commercial instruments, which limits spreading. Glow discharge is much more reliable than spark-source mass spectrometry. GD-MS is particularly valuable for studies of alloys and semiconductors [371], Detection limits at the ppb level have been reported for GD-MS [372], as compared to typical values of 10 ppm for GD-AES. The quantitative performance of GD-MS is uncertain. It appears that 5 % quantitative results are possible, assuming suitable standards are available for direct comparison of ion currents [373], Sources of error that may contribute to quantitative uncertainty include sample inhomogeneity, spectral interferences, matrix differences and changes in discharge conditions. 

FFF Field-flow fractionation GD-(MS) Glow-discharge (mass spectrometry)... 

There is a branch of MS specially designed for dealing with the analysis of inorganic materials.[21,22] Different specific ionization techniques, such as inductively coupled plasma mass spectrometry (ICP-MS),[23] glow discharge mass spectrometry (GD-MS)[24] and secondary ion mass spectrometry (SIMS),[25] are available and they are widely used in cultural heritage applications. Their description is beyond the scope of this chapter. 

Glow discharge source (GDMS) Laser ion source (LIMS) Secondary ion source (SIMS) Sputtered neutral source (SNMS) Thermal ionization source (TIMS) Inductively coupled plasma ion source (ICP-MS)... 

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