Mass spectrometry with inductively coupled plasma
Mass spectrometry with inductively coupled plasma ( English inductively coupled plasma mass spectrometry , ICP-MS ) is a robust, very sensitive mass spectrometric analysis method in inorganic element analysis . She will u. a. used for trace analysis of heavy metals such as mercury , lead or cadmium .
functionality
In ICP-MS (inductively coupled plasma mass spectrometry), a high-frequency electromagnetic field is used to generate a plasma in an argon gas stream, in which a sample aerosol can be heated to 5,000-10,000 ° C. The sample components are evaporated, broken down into their atomic components and these are efficiently ionized. The ions generated in the plasma are then transferred to the analyzer of a mass spectrometer . There the isotopes of the individual elements are recorded by measurement.
With ICP-MS, detection limits in the range of nanograms per liter (ng / l) or better are achieved for most of the elements of the periodic table . In addition, the quantitative determination of the method is characterized by a very wide linear range over nine to twelve orders of magnitude. In addition to quantitative analytical tasks, the ICP-MS can also be used for precise isotope analysis. For this purpose, generally sector field ICP mass spectrometer used.
By coupling it with analytical separation methods such as high-performance liquid chromatography , gas chromatography , capillary electrophoresis , gel electrophoresis , ion exchange chromatography and field-flow fractionation , the ICP-MS can also be used for speciation analysis. Furthermore, solid samples can be analyzed directly by coupling with a special furnace for electrothermal evaporation or with a laser ablation device. With the latter, a spatially resolved, quasi-non-destructive analysis is possible, for example on historical objects.
Alternative methods
Other important methods of elemental analysis are:
- Optical emission spectrometry with inductively coupled plasma (ICP-OES)
- Instrumental Neutron Activation Analysis (INAA)
- X-ray fluorescence analysis (XRF)
- Atomic Absorption Spectrometry (AAS)
literature
- RS Houk, VA Fassel, GD Flesch, AL Gray, E. Taylor: Inductively coupled argon plasma as an ion source for mass spectrometric determination of trace elements. In: Analytical Chemistry . 52, No. 14, 1980, pp. 2283-2289, doi : 10.1021 / ac50064a012 .
- D. Skoog, J. Leary: Instrumental Analytics. Basics, devices, application. Springer, Berlin 1996, ISBN 3-540-60450-2 (German translation of the 4th edition of Principles of Instrumental Analysis, Orlando 1992).
- SM Nelms: Inductively coupled plasma mass spectrometry handbook. Blackwell, Oxford 2005, ISBN 1-4051-0916-5 .
- HE Taylor: Inductively Coupled Plasma-Mass Spectrometry. Academic Press, San Diego 2001, ISBN 0-12-683865-8 .
- R. Thomas: Practical Guide to ICP-MS. Dekker, New York, 2004, ISBN 0-8247-5319-4 .
