Detection and analysis of microplastics in offshore sediment by microscopic differential Raman spectroscopy

In view of the problems of low pre-screening efficiency, a weak Raman signal, and strong fluorescence interference in the detection of microplastics by traditional Raman spectroscopy, a set of rapid detection system and research methods for microplastics, including fluorescence imaging technology, differential Raman spectroscopy technology, and confocal microscopic Raman technology, are constructed in this paper. A 784/785 nm dual-wavelength laser was used as the excitation light source in the rapid detection system for microplastics. The sediment in the coastal waters of Qingdao Shilaoren was taken as the research object. Polycarbonate and high-density polyethylene with a particle size of 40 µm in the samples were accurately detected and analyzed. The research method for microplastics proposed in this study breaks through relevant key technologies, which we believe will help promote the development of microplastic monitoring technology in the global marine environment and provide strong technical support for the healthy development of the global marine ecological environment.