Inductively Coupled Plasma–Mass Spectrometry (ICP–MS): Overview

Inductively coupled plasma–mass spectrometry, or ICP–MS, uses an ICP source to prepare samples for atomic mass spectrometry.

Solution-state samples are nebulized and passed through high-temperature argon plasma.

The plasma breaks down the analyte and ionizes its component atoms, and the mass spectrometer determines the relative amount of each element.

Notably, an ICP functions at atmospheric pressure, while a mass spectrometer operates in a vacuum, so an interfacial region consisting of a pair of metallic cones steps down the pressure, which is reduced further with each section.

The miniscule sample cone orifice admits only a small amount of plasma, which expands and passes through the even smaller orifice of the skimmer cone. Then, the extraction lens separates the positive ions, which enter the collision cell.

There, the range of kinetic energies among the ions is reduced, and the ion beam is guided into the quadrupole mass analyzer, where the ions are separated and sent to the detector. 

ICP–MS is used in elemental analysis and provides low detection limits and excellent sensitivity.