Technology critical elements (TCE) are a key material for advanced technology, but their supply in the EU is a challenge. A sustainable solution to address this problem is recycling, but difficulties in analyzing waste streams are a complicating factor. The overall aim of this project is to enable the representative SI-traceable determination of TCE in the µg/g range in municipal waste. Transferable calibration methods and suitable reference materials are to be developed in order to improve TCE recycling in the context of the circular economy. The target industries belong to the recycling chain, including multinational companies, SMEs and R&D institutes.