Electro-thermal vaporisation

James, M.R., Wayman, T., Stellmacher, K. and Hall, R.J.B., The determination of plutonium in urine by electro-thermal vaporisation inductively coupled mass spectrometry (ETV-ICP-MS), presented at 3rd Surrey Conference on Plasma Source Mass Spectrometry, Manchester, England, July 1989. 

Figure 2.15 Schematic diagram of electro-thermal vaporisation apparatus suitable for attachment to ICP-OES. (Reproduced by kind permission copyright 1999-2008, all rights reserved, Perkin Elmer, Inc.)...

Metal Analysis Using ICP-OES Coupled with Electro-Thermal Vaporisation... 

The introduction of an electro-thermal vaporisation (ETV) unit to an ICP-OES plasma source can be used for most solid and liquid samples with considerable ease. Drying and pyrolysis can remove the solvent and major components and the residual analytes are vaporised and transported by the argon gas flow to the ICP-OES plasma source where metals of interest are detected with a rapid CCD detector. The ETV sampling/analysis provides higher analytical transport efficiencies and can detect very low trace levels of metals (i.e. in the ppt range). 

Introducing samples to the plasma via liquids reduces sensitivity because the concentration of the analyte is limited to the volume of solvent that the plasma can tolerate. An electro-thermal method seems an obvious choice to increase the detection limit as it will vaporise entirely most neat samples or using an increased concentration of sample in a suitable solvent. The sample is placed on a suitable open graphite rod in an enclosed compartment and heated rapidly (Figure 2.15). The electronics required for ICP-OES-ETV (inductively coupled plasma-optical emission spectroscopy-electro-thermal volatilisation) is similar to that for A AS and detection limits are better than ICP-AES. 

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