Infrared Spectroscopic Identification of Microplastic Contamination <20um using Simultaneous Submicron IR + Raman
Friday, March 12, 2021: 2:10 PM - 2:30 PM
Plastic contamination is a widespread and global problem in our environment. Attention was heightened when media showed the negative impact of plastic usage and careless disposal when large “garbage patches” where found in the world's great oceanic gyres. Many groups have taken on the task of cleaning these large fields of debris, but much work needs to be done. As these plastics fracture these smaller particles are called microplastics, (MP’s) and these have become of great concern over recent years as these smaller particles can interact with living organisms in different fashions and have the potential to cross cell membranes at smaller sizes <20 micron. As plastics fracture into smaller pieces the ability to measure and characterize them becomes problematic with standard methods like FTIR. Conventional FTIR systems have problems measuring MP’s as they approach the Abbe limits of 10-20 microns in size due to the wavelengths of light used for IR measurements. Other affects also create problems with traditional FTIR artifacts when trying to measure small particles including specular, diffuse, and Mie scattering. Our approach is to utilize a new IR vibrational technique called Optical Photothermal Infrared or O-PTIR. This technique overcomes traditional limitations of spatial resolution, operates in non-contact, collection mode is in reflection, and uses a new dual vibrational technique called IRRSim mode. This technique provides simultaneous collection of submicron spatial resolution infrared (IR) and Raman spectra to help more thoroughly characterize the particles of contamination. These two complimentary vibrational spectroscopy techniques provide key insights into the identification, distribution, and amounts of contamination identified.
Keywords: Please select up to 4 keywords ONLY:
Aerosols/Particulates,Environmental - Water,Hyphenated Techniques - Other