Informing Spectroscopists for Over 40 Years

ICP-mass spectrometry: Let the isotopes do the talking!

Frank Vanhaecke and Luc Moens

Department of Analytical Chemistry, Ghent University, Krijgslaan 281–S12, BE-9000 Ghent, Belgium. E-mail: [email protected]

Introduction

Inductively coupled plasma-mass spectrometry (ICP-MS) was introduced commercially in 1983 as a very sensitive analytical technique to be deployed for (ultra)trace element analysis. Compared to the previously existing techniques of atomic absorption spectrometry (AAS) and ICP-optical emission spectrometry (ICP-OES), the main advantages offered by ICP-MS over these techniques were its pronounced multi-element capabilities and substantially higher detection power, respectively.

As a mass spectrometric device, ICP-MS, however, also provides isotopic information on the analyte elements and this feature can be taken advantage of for further extending the application range of ICP-MS and for tackling real-life problems for which elemental information does not provide sufficient information. While the “standard” ICP-MS equipment—equipped with a quadrupole filter or a sector field mass spectrometer for mass analysis and a single ion detector only—can be deployed for studying induced and relatively large natural variations in the isotopic composition of target elements, multi-collector (MC) MC-ICP-MS—equipped with a sector field mass spectrometer and an array of ion detectors, allowing simultaneous detection of the intensity of the ion beams corresponding to all isotopes of a target element—is a dedicated tool for highly precise isotopic analysis, also permitting one to trace down extremely small natural variations. Real-life applications carried out at the Department of Analytical Chemistry of Ghent University and based on the use of both single- and multi-collector instrumentation will be used in this article to illustrate the wide application range of isotopic analysis via ICP-MS.