What Is an Inductively Coupled Plasma Mass Spectrometer?

An inductively coupled plasma mass spectrometer (ICP-MS) is used to determine the concentration of particular elements in a rock and soil samples for geological studies. The ability to identify the contents of samples is beneficial in mineral exploration. A hybrid of an inductively coupled plasma mass spectrometer is useful in providing the isotopic age of minerals for radiometric dating. This technology was first used in the 1960s as a method for growing crystals. It has been improved for use as an analytical tool for environmental purposes.

Inductively coupled plasma mass spectrometers work quickly and are well suited for analyzing large amounts of sediment and soil samples. A solution of sediment or rock is placed into plasma, and the concentration of the sample is determined by the light emitted. The equipment can identify more than 40 elements. Argon is one of the elements that a mass spectrometer cannot identify.

The ICP-MS equipment has three tubes, which are normally made from silica and create the torch portion of the equipment. The equipment's torch portion is in a coil, which is cooled with water, inside a radio frequency generator. When gases are run through the torch, a radio frequency field becomes activated. The gas inside the coil then becomes conductive.

An inductively coupled plasma mass spectrometer then measures the light that is emitted by the ions in the sample. The light is converted to electrical signals, and the intensity of the resulting signals are compared to known intensities. The matching of the results to known information is what identifies the element. Elements can have many wavelengths, which makes experience a critical factor when performing analysis.

A multicollector-inductively coupled plasma mass spectrometer (MC-ICPMS) is used in geochronology. Geochronology uses the measurement of radioactive decay to determine the age of a sample. In this system, ions are produced by introduction into plasma that strips away electrons, leaving the positive ions. The ions are accelerated and then focused. The focused beam passes through a filter, which separates the ions based on their mass.

Both the MC-ICPMS and ICP-MS use the system of comparing measured voltages to obtain scientific results. Inductively coupled plasma mass spectrometers can be found in laboratories that are involved in soil and water sampling. They are useful in geochemistry and chemical ecology studies. They can detect sulfur, phosphorus and boron, so they work very well for testing the purification in water distribution systems.