Improving PCBs’ recycling rate and efficiency is a pressing need to achieve a circular economy and resource independence. Our research aims to address this need by showcasing the potential of a novel X-ray fluorescence (XRF) methodology. This method applied to a sample set of 45 mobile phone PCBs produced between 1998 and 2021, has shown significant improvements in the accuracy of XRF analysis results, with variations within 5-10 % compared to the certified reference concentrations. The results of the longitudinal material composition screening of PCBs from mobile phones demonstrate clear increasing trends in Cu, Ni, Sn, and Fe concentration, while simultaneously decreasing trends in concentration of precious and hazardous metal concentrations, such as Au, Pd, Co, Pb, and Hg. This research showcases the XRF methodology as a game-changer in the field of PCB recycling. It is a fast, reliable, and cost-effective analytical method that opens up new, currently untapped potentials. Expanding the number of recyclable elements paves the way for recycling and recovery processes tailored to the specific input material feed.