Author(s): Jenna Olivier
Mentor(s): Gabriela Chilom
Institution UTech
Microplastics—plastic particles under 5mm in diameter—are widespread pollutants in water, air, and soil, posing significant risks to wildlife and human health. Annually, 33 billion pounds of plastic enter Earth's oceans, highlighting the urgent need to understand and quantify pollutant plastics to support local remediation. However, standardized methods for identifying and quantifying microplastics in complex matrices like soil are not yet established. This project aims to determine the detection limits for common microplastics in soil mixtures using two accessible techniques: Fourier-Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). Four plastics—high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET)—were shredded, sieved, and mixed with local soils from the Virgin River and Northern Hurricane to create spiked samples at 0.5% to 5% by weight. FTIR successfully identified plastic types at higher concentrations, while DSC proved effective across both low and high concentrations, with distinct melting points observed for each plastic. These findings underscore the potential of FTIR and DSC for measuring and identifying microplastics in complex soil matrices, and highlight the need for improved sample preparation techniques. Future research will refine these methods to enhance detection sensitivity and consistency, supporting more effective environmental monitoring and remediation efforts.