Organofluorine compounds—sometimes called "forever chemicals"—are increasingly turning up in our drinking water, oceans and even human blood, posing a potential threat to the environment and human health. Now, researchers at The University of Texas at Austin have developed a way to fingerprint them, which could help authorities trace them to their source when they end up in aquifers, waterways or soil. The technique involves passing samples through a strong magnetic field, then reading the burst of radio waves their atoms emit. This reveals the composition of carbon isotopes in the molecule and gives the chemical its fingerprint, a feat that had not previously been achieved with forever chemicals. .....