The Inductively Coupled Plasma (ICP) ion source is a very efficient ion source for elemental and isotopic analysis using mass spectrometry. This is an analytical method that is capable of detecting elements at very low concentration, as low as one part in 10¹⁵ (part per quadrillion, ppq) on non-interfered, low-background isotopes. The method involves ionizing the sample to be analysed with an inductively coupled plasma and then using a mass spectrometer to separate and quantify the thus generated ions.

Ionizing a gas, usually argon, in an electromagnetic coil, to generate a highly energized mixture of argon atoms, free electrons and argon ions, generates the plasma, in which the temperature is high enough to cause atomization and ionisation of the sample. The ions produced are introduced, via one or more stages of pressure reduction, into a mass analyser which is most commonly a quadrupole analyser, a magnetic sector analyser or a time-of-flight analyser.

A description of ICP mass spectrometers can be found in the articles A Beginner's Guide to ICP-MS by Robert Thomas (SPECTROSCOPY 16(4)-18(2), April 2001-February 2003), the disclosure of which is hereby incorporated by reference in its entirety (however, where anything in the incorporated reference contradicts anything stated in the present application, the present application prevails).

A known design of multi-collector (MC) ICPMS instrument is the NEPTUNE? or NEPTUNE Plus?, as described in brochures and operating manuals from Thermo Scientific, the disclosures of which are hereby incorporated by reference in their entirety (however, where anything in the incorporated reference contradicts anything stated in the present application, the present application prevails).