Our environment contains millions of different chemicals, but we don't know what most of them are. Even with advanced analytical tools like mass spectrometry, many of the detected signals cannot be matched with any known chemicals. The Huan lab at the Social Exposome Cluster recently came up with a revolutionary approach to identify these unknown chemicals using tandem mass spectrometry. This breakthrough could help us better understand and characterize previously unknown environmental chemicals, and how they affect our health over our entire lives. Read the Nature Methods article: https://www.nature.com/articles/s41592-023-01850-x