Analysis of Microplastic Types and Sizes Using a Fluorescence-based Optical System

Abstract

Microplastics have been increasingly detected in various environmental media, including marine ecosystems, the atmosphere, soil, and drinking water, and more recently, in human tissue, which raises significant health concerns. Conventional analytical techniques such as Raman spectroscopy, Fouriertransform infrared spectroscopy (FTIR), and gas chromatography–mass spectrometry (GC–MS) have limitations in analysis speed, sample destructiveness, and processing efficiency. To address these challenges, we propose a high-sensitivity optical analysis system based on laser-induced fluorescence (LIF). This integrated system combines fluidic and optical components for automated, continuous measurements. It facilitates real-time identification of microplastic types including polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC), and particle sizes of 100, 200, 300, and 500 µm. Key analytical metrics, including fluorescence spectral gradient (G) and integral area (A), were employed, and the system demonstrated high precision and reproducibility with 100 repeated measurements. This approach offers rapid, non-destructive analysis and provides a foundational technology for environmental monitoring and on-site applications.