Compound-specific 14C analysis was introduced in the late 1990s and has since matured into a useful tool for a large range of applications in Ocean Sciences. The technique relies on the ability to extract and isolate organic compounds of known origin from the complex matrix of marine environmental samples, particularly from sediments. The advent of improved accelerator mass spectrometry technology has greatly advanced the field, enabling analysis of small quantities of highly-purified molecules. Applications range from studies of carbon cycling in continental and marine reservoirs to microbial ecology.