Glow discharge source, trace analysis

The conventional method for quantitative analysis of galHum in aqueous media is atomic absorption spectroscopy (qv). High purity metallic galHum is characteri2ed by trace impurity analysis using spark source (15) or glow discharge mass spectrometry (qv) (16). 

Glow discharge GD Plasma source Atomic ions Trace analysis... 

A GD mass spectrometer from Thermo Fisher Scientific with a direct current (dc) glow discharge ion source based on the mass spectrometric arrangement of the Element (Element GD) has been available on the analytical market since 2005 for sensitive multi-element analysis of trace impurities in conducting samples. The experimental arrangement of the dc GD ion source (Grimm type) and... 

Table 9.4 Result of trace analysis of high purity indium and zinc measured by spark source mass spectrometry (SSMS) and glow discharge mass spectrometry (GDMS), respectively.

Four techniques based on mass spectrometry are widely used for multi-elemental trace analysis of inorganic compounds in a wide range of sample types. These techniques are thermal ionization (TI), spark source (SS), glow discharge (GD) and inductively coupled plasma (ICP) mass spectrometry. In these techniques, atomization and ionization of the analysed sample are accomplished by volatilization from a heated surface, attack by electrical discharge, rare-gas ion sputtering and vaporization in a hot flame produced by inductive coupling. 

Preferred methods in trace determination of the elements include atomic absorption spectrometry (AAS), optical emission spectrometry (OES) with any of a wide variety of excitation sources [e.g., sparks, arcs, high-frequency or microwave plasmas (inductively coupled plasma, ICP microwave induced plasma, MIP capacitively coupled micro-wave plasma, CMP), glow discharges (GD). hollow cathodes, or laser vaporization (laser ablation)], as well as mass spectrometry (again in combination with the various excitation sources listed), together with several types of X-ray fluorescence (XRF) analysis [51]. 

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