Mass-independent isotope fractionation of heavy elements measured by MC-ICPMS: a unique probe in environmental sciences

This article overviews recent developments in the use of multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) in studies of mass-independent isotope chemistry of heavy elements. Origins of mass-independent isotope effects and their relevance to isotope ratio measurements by MC-ICPMS are briefly described. The extent to which these effects can affect instrumental mass bias in MC-ICPMS is critically discussed on the basis of the experimental observations. Furthermore, key findings reported in studies of mass-independent isotope fractionation (MIF) of mercury in the field of environmental sciences are reviewed. MIF of heavy elements is not only of interest from a fundamental point of view, but also provides scientists with a new and effective means of studying the biogeochemistry of these elements.