Use of compound-specific isotope analysis (CSIA) to assess the origin and fate of chlorinated hydrocarbons

Abstract

This chapter provides a comprehensive presentation of how compoundspecific- isotope analysis (CSIA) can be used to evaluate the origin and fate of chlorinated hydrocarbons at the laboratory or field scale. It lays the foundation by introducing concepts to quantify isotope fractionation associated with reactive processes, explaining what causes such changes and presenting current methods to determine C, Cl and H isotope ratios. It then discusses how the transformation of a compound by various mechanisms can be differentiated using isotope ratios of multiple elements. It also summarizes the current knowledge about isotope fractionation during the transformation of common classes of chlorinated hydrocarbons. Finally, strategies to apply isotope methods at the field scale to track different sources of contamination or the type and progress of reactive processes are outlined.