An inductively coupled plasma (ICP) is a very high temperature (7000-10,000 K) excitation source that efficiently desolvates, vaporizes, excites, and ionizes atoms. Molecular interferences are greatly reduced with this excitation source but are not eliminated completely. ICP sources are used to excite atoms for atomic-emission spectroscopy and to ionize atoms analysis.
Instrumentation -- The sample is nebulized and entrained in the flow of plasma support gas, which is typically Argon (Ar). The plasma torch consists of concentric quartz tubes. The inner tube contains the sample aerosol and Ar support gas and the outer tube contains flowing gas to keep the tubes cool. A radio frequency (RF) generator (typically 1-5 kW @ 27 MHz) produces an oscillating current in an induction coil that wraps around the tubes. The induction coil creates an oscillating magnetic field, which produces an oscillating magnetic field The magnetic field in turn sets up an oscillating current in the ions and electrons of the support gas (argon). As the ions and electrons collide with other atoms in the support gas.
Instrumentation -- As in AAS, the sample must be converted to free atoms, usually in a high-temperature excitation source. Liquid samples are nebulized and carried into the excitation source by a flowing gas. The excitation source must desolvate, atomize, and excite the analyte atoms. The following is an illustration of the instrument located in 108. Check the following for instrumental details and procedures.
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