. . "Assessing Transformation Processes of Organic Compounds Using Stable Isotope Fractionation" . . . "Compound-specific stable isotope analysis makes it possible to infer the origin and transformation pathways of organic compounds." . . "Quantifying the transformation processes of organic compounds in the environment using conventional methods is a major challenge due to the effects of dilution, volatilization, or sorption to the environmental matrix. Assessing these processes is key to addressing the risks of soil and water contamination. Hofstetter et al. illustrate how changes in isotope signatures provide unique information on reaction pathways and open new avenues to assess the sources and transformation processes of organic compounds." . . . . . . . . .