Inductively-coupled plasma mass spectrometry (ICP-MS) is a technique used to determine inorganic elemental composition. Both solid and liquid samples can be analyzed by this method. ICP-MS utilizes a RF-generated argon plasma gas to sequentially desolvate, vaporize, atomize, and ionize samples for elemental analysis. The ionized elements pass into a mass analyzer for separation based on their mass/charge (m/z) ratios. Each element has a series of m/z ratios which are characteristic of its naturally occurring isotopes. Scanning across a broad m/z range allows detection of over 70 elements across the periodic table. In addition to providing a qualitative elemental profile, ICP-MS measurements also generate quantitative information down to the parts per trillion (ng/L) level.
ICPMS is a hybrid technique consisting of an inductively coupled plasma (ICP) interfaced to a mass spectrometer (MS) and is used for simultaneous multi-analyte determination of ~82 elements on the periodic table. The ICP is one of several types of plasma discharges used in analytical atomic spectroscopy created using inert gases, typically argon. The plasma is created by ionization of plasma gas in an electromagnetic field produced within the confines of a work coil using a radio-frequency signal. Collisions between gas atoms and charged particles in the plasma result in a temperature of ~8000K inside the plasma discharge. The plasma discharge is a ‘hard’ ion source, effectively decomposing all sample components into their constituent atoms then ionizing these atoms. The ions produced are extracted and transferred through a specially designed interface into a mass spectrometer where they are sorted and measured based on their mass charge ratio. Virtually all mass spectrometer designs have been interfaced to the ICP ion source, with commercially available systems using quadrupole, time-of-flight, magnetic sector, and triple-quad mass spectrometers. Liquid based sample introduction systems are available for analysis of both aqueous and organic samples, and direct analysis of solid samples can be performed using laser ablation and spark sources. ICPMS systems are also used as detectors for gas and liquid chromatography, and capillary electrophoresis systems. Unique capabilities include dynamic range up to 11 orders of magnitude, capability for full quantitative analysis and rapid semi-quantitative screening analysis, and access to isotopic information used in isotopic ratio analysis and high performance quantitative analysis by isotope dilution.