A laser-based saturated-absorption cavity ring-down technology for precise biobased content analysis of plastic samples

The integration of biobased materials into the plastics market is inevitable to meet European and global targets for carbon-neutral and sustainable production. To support the research, supply and production chains of bioplastics, independent analytical methods are needed to verify the biobased content of raw and final materials. In addition to the recently adopted accelerator mass spectrometry (AMS) method, we present a laser-based saturated-absorption cavity ring-down technology (SCAR) for accurate biobased content determination based on radiocarbon measurement. The traditional AMS method was compared with the state-of-the-art SCAR laser technology to verify the capability of the method. The method was successfully demonstrated to be capable of verifying the biobased content of plastic materials with an accuracy of <1% (absolute) over the entire range from fossil (0%) to fully biobased (100%). The applied measurement time of 50–60 min is comparable to AMS. No systematic offset or 14C concentration-related shift was observed between the two methods, demonstrating that the SCAR method is reliable and can be adopted for research and industrial applications. The rapid, automated measurement protocol using an elemental analyzer makes the method suitable for high throughput applications. Dissemination of the cheaper laser-based technologies to biobased research and industry can help to speed up the integration of biomaterials into the market.