Analysis of Microplastics Using AIRsight Infrared/Raman Microscope

Introduction

Pollution of rivers and oceans by microplastics is spreading on a global scale, and there are concerns about its impact on living organisms. In recent years, monitoring surveys and research have been actively conducted to obtain scientific knowledge about the distribution of microplastics in around the world. When exposed to UV rays, rain and wind, and brittle by physical friction, the plastic released into the environment becomes even smaller, becoming microplastics.(The microplastics here are called secondary microplastics.). Generally, evaluation items for microplastics include observation of their appearance, measurement of their number and size, and qualitative analysis of materials. Among these evaluation items, qualitative analysis of material is one of the most important items for identifying the origin of microplastics, but the size of microplastics to be evaluated is getting smaller year by year, requiring the selection of appropriate analytical instruments. A size-specific analysis method for microplastics is shown in Figure 1. Micro-Raman spectroscopy is possible to analyze smaller particles than micro- infrared spectroscopy and is easier to analyze than pyrolysis- gas chromatography-mass spectrometry. AIRsight Infrared/Raman microscope is a new type of microscope that incorporates a Raman unit into an infrared microscope, making it possible to perform both Raman and infrared analysis on a single instrument, which was previously required for each instruments had been required until now. This article introduces an example of evaluating microplastics in the environment using AIRsight.