Potential and limits of speciated isotope-dilution analysis for metrology and assessing environmental reactivity
Abstract
This paper describes the application of isotopically labelled elemental compounds for species-specific isotope-dilution (ID) analysis and for species transformation evaluation with the focus on organotin species and methylmercury in both analytical and environmental studies. Among others, the accurate measurement of organometallic compounds (speciation) in environmental samples can be hampered by processes such as incomplete extraction from solid samples, material loss, rearrangement reactions during extraction and/or derivatization, low recoveries, and signal drift. All these undesirable effects, with the exception of incomplete species extraction from the sample matrix, can be studied and/or corrected for using speciated ID analysis (IDA). The use of compounds enriched in stable isotopes with subsequent detection by inductively coupled plasma mass spectrometry (ICP-MS) is a powerful tracer technique to study dynamic environmental processes. We also present an overview of other work published in this area. We discuss limitations of the applicability of speciated IDMS. © 2004 Elsevier Ltd. All rights reserved.