Utility of Stable Isotopes of Hydrogen and Carbon as Tracers of POPs and Related Polyhalogenated Compounds in the Environment

Abstract

Polyhalogenated persistent organic pollutants (POPs) belong to the most hazardous environmental pollutants of our days. The concentrations of compounds such as PCBs, PCDD/Fs, chloropesticides, and brominated flame retardants in the environment are well-documented. In order to determine the origins and fate of the POPs, however, the concentrations in the environment must be related to the processes that redistribute these pollutants. A suitable tool for such a purpose is stable isotope analysis. This chapter describes the techniques used for the determination of stable carbon and hydrogen isotopes of POPs. Element analyzer-isotope ratio mass spectrometry (EA-IRMS) was used for the determination of bulk δ13C values and bulk δ2H values. Linking of a gas chromatograph to IRMS enabled the compound-specific isotope analysis (CSIA) of δ13C values. Moreover, theoretical aspects as to the intramolecular deuterium distribution can be explored by means of quantitative 2H-NMR. The knowledge of published applications in stable isotope analysis of POP is presented. On several occasions IRMS data was suited to distinguish technical products from different producers, metabolites from native POPs, and to address kinetic isotope effects (KIE) during the transformation of POPs. Problems and limitations of the current state of the art in stable isotope analysis of POPs are presented as well.