Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is an analytical technique for measuring the elemental concentrations of samples.
A sample is introduced as an aerosol typically, and then passes into a plasma torch. The high temperature plasma source ionizes the sample by removing electrons. The ions then pass through a series of cones into the mass spectrometer, usually a quadrupole.
The cones allow the central portion of the ion beam from the plasma torch to be sampled. Once the ions enter the mass spectrometer, they are filtered through the quadrupole by their mass-to-charge ratio, such that only ions with a single, particular mass-to-charge ratio can pass through the mass spectrometer at a time. When the ions exit the mass spectrometer they are detected by converting the number of ions striking the detector into an electrical signal.
Standards of known concentration are used to calibrate the relationship between the electrical signal and the abundance of atoms of a given element. This relationship is applied to the sample’s measured electrical signal to quantify the abundance of a given element in the sample.
The elemental concentrations of various materials are measured using ICP-MS. These materials can be geological, chemical, biological, environmental, petrochemical, metallurgical, medical or archeological samples. Examples of geological materials include trace elements in rocks, sediments, soils, mineral separates and fossils. Ground water and seawater are good examples of environmental materials. Medical samples include bone, tissue, urine and blood. Trace elements are measured in archeological materials including bone, ceramic and other artefacts.
