Inductively coupled plasma mass spectrometry

Inductively coupled plasma mass spectrometry (ICP-MS) combines plasma chemistry, which produces singly charged elemental ions, with mass spectrometric detection. Unlike other mass spectrometry ionization sources, the ICP can efficiently handle liquid, solid and gaseous samples. Nuclides of metals, metalloids and some non-metals — such as sulfur, phosphorus and halogens — can be ionized, with an ionization degree that depends on the intrinsic properties of the element and sample matrix. As a stand-alone technique, ICP-MS excels in (ultra-)trace multi-elemental analysis and isotopic analysis. Combined with chromatographic separations, molecules are assessed as elemental species, whereas laser ablation-ICP-MS enables direct sampling from solid surfaces, either in the imaging modality or for bulk analysis. Scanning-type mass analysers, such as quadrupole-based mass spectrometers and sector field mass spectrometers, dominate the field. Time-of-flight ICP mass spectrometers are considered the go-to instruments for multi-elemental analysis of microscale and nanoscale particles and single cells as discrete entities in a time-resolved manner. This Primer covers the major analytical applications of ICP-MS — multi-element, single-particle, single-cell, laser ablation, speciation and isotopic analysis — and outlines the underlying measurement strategies, challenges and example applications.