Inductively coupled plasma torches

Because light emitted from inductively coupled plasma torches is characteristic of the elements present, the torches were originally introduced for instruments that optically measured the frequencies and intensities of the emitted light and used them, rather than ions, to estimate the amounts and types of elements present (inductively coupled plasma atomic emission spectroscopy. 

In the plasma deposition process, siUcon tetrachloride vapor is passed through an induction-coupled plasma torch using a hydrogen-free oxygen... 

Figure 1. Cross section of induction-coupled plasma torch, plasma, and radio...

Figure 15.1—Inductively coupled plasma torch. A radiofrequency current (between 27 and 50 MHz) that induces circulation of the electrons in the inert gas drives the torch. The argon serves as an auxiliary gas, a cooling gas and the nebulisation gas. In the upper right is shown an optic device used to collect emitted light in the longitudinal axis of the plasma. Lower down, plasma generated by microwave.

A second plasma emission source which has become the most popular is the inductively coupled plasma torch (ICP). Figure 8.11 illustrates a typical source construction, which consists of three concentric quartz tubes. An aerosol of the sample solution in injected into the plasma through the central tube in a stream of argon flowing at about I dm3 min A higher flow ofargdn... 

Allemand, D. and Barnes, R.M. (1977) A study of inductively coupled plasma torch configurations, Applied Spectroscopy, 31, pp434 t43. 

Reed T. B. (1961) Induction-coupled plasma torch, J Appl Phys 32 821-824. 

Figure 10 A cut away representation of the three concentric tube design of an argon inductively coupled plasma torch. The pneumatically generated sample aerosol is entrained up through the central quartz tube and enters the hole of the toroidally shaped plasma.

The first commercial plasma atomic fluorescence spectrometer was developed by Demers and Allemand. Hollow cathode lamps are used as radiation sources and an inductively coupled plasma torch as an atomizer. Detection limits are reported for more than 30 elements. The linear dynamic range is normally 10 to 10. ... 

Interfacing mass spectrometry with other analytical techniques (Section F) necessitates the use of specially designed interfaces and ionizing sources. These include thermospray, electrospray and ionspray for liquid chromatography-mass spectrometry (LC-MS), and an inductively coupled plasma torch (ICP) for ICP-MS (Topic E5). For gas chromatography-mass spectrometry (GC-MS), the carrier gas flows directly into the spectrometer where El ionization can then be used. 

FIGURE 6 Schematic representation of an inductively coupled plasma torch during operation. 

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