Technology-critical elements (TCEs) are essential for modern high-tech devices, including smartphones and renewable energy systems. As demand increases due to the shift towards a greener economy, the European Union's reliance on imported TCEs creates market pressures. Recycling offers a sustainable solution, but this process requires reliable analytical methods to ensure accurate monitoring of TCEs in waste materials. Presently, certified reference materials (CRMs) for TCEs in recycled waste streams are limited, especially in heterogeneous materials like LED scrap, which contain a complex mixture of metals, ceramics, glass, and plastics. 

This study provides essential data for the development of a LED CRM, offering a reliable reference for TCE monitoring in recycling processes, thus supporting the circular economy.