Researchers have introduced an innovative method using in-line nuclear magnetic resonance (NMR) to analyze and selectively transform complex plastic waste mixtures into valuable chemicals. Published in Nature, the approach employs solid-state 1H–13C FSLG-HETCOR NMR to resolve chemical structures within mixed polymers and guide targeted catalytic recycling under mild conditions. This scientific advancement addresses the heterogeneity challenge in plastic recycling and promotes sustainable waste management.