Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 149733

149733 - Microplastic Detection and Quantification in Water Using Py-Gc/ms Methodology 

Plastic production and consumption have grown drastically over the past few years. Plastic pollution is of significant concern as only 9% of the total plastics produced have been recycled to date leaving the remaining a possible source of plastic pollution. These synthetic polymer materials undergo environmental degradation leading to the formation of microplastics. The microplastics being less than 5mm in size end up in the aquatic ecosystem through surface run-offs.  The presence of microplastics in the surface and groundwater poses a significant challenge to public health, as they could be transported to the tap water. The small size of microplastics makes their detection and quantification challenging using conventional microscopy and spectroscopy techniques. Moreover, the absence of mass-loading information limits the understanding of the environmental loading of these particles. To address these limitations, a pyrolysis Gas Chromatography-Mass Spectroscopy (py-GC/MS) multi-polymer identification method was developed for the quantification of both traditional and non-traditional polymers. The developed method was successful in quantifying seven different types of polymers, including Polyethylene (PE), Styrene-Butadiene Rubber (SBR), Polypropylene (PP), Polystyrene (PS), Polymethyl Methacrylate (PMMA), Acrylonitrile Butadiene Styrene (ABS), and Nylon-66 (N-66). Each polymer was identified with key markers such as 1-decene (PE), butane, 1-cyano (SBR), 2,4-dimethyl-1-heptene (PP), styrene (PS), methyl methacrylate (PMMA), 5-phenyl-1H-benzotriazole (ABS), and cyclopentanone (N-66). High accuracy and precision in quantification were achieved through the analysis of these markers. The method developed utilizes a single-shot mode with a furnace temperature of 600 °C and a pyrolysis time of 12 seconds. The interface temperature was maintained at 300 °C, employing a scan range of 29–350 m/z and a split ratio of 50:1. The four-stage program starts at 40 °C and gradually increases to 320 °C, with a total run time of 23 minutes. Seven different mass concentrations of a 12-blend microplastic standard with inert CaCO₃ diluent were used to develop calibration levels for all seven polymers, and the determination coefficient (R²) was calculated as follows: PE (0.99942), PP (0.9981), PMMA (0.99651), N-66 (0.99859), PS (0.99942), SBR (0.99923), and ABS (0.99917). The high R² values denote the high accuracy of the method in detecting the polymers. The limit of detection (LOD), limit of quantification (LOQ), and intra/interday precision were measured and reported. The method optimization yielded a low LOD of 0.01 to 2.59 μg and an LOQ of 0.05 to 8.62 μg, highlighting high accuracy and sensitivity to all the polymers analyzed. Intra- and interday precision (RSD %) varied from 3.36 to 8.38 and 3.8 to 10%, respectively, with R² ranging from 0.9965 to 0.9995. The validation of the analytical method was conducted by analyzing a multiplastic standard (2 mg total mass) contaminated with DI water and successfully detecting and quantifying PE, SBR, PMMA, ABS, N-66, and PS, with PP below the LOD. The validation demonstrated the method's effectiveness and applicability in detecting and quantifying microplastics in environmental samples. The analytic method is a promising alternative to conventional methods that can be adopted by researchers and regulatory bodies to initiate better management practices and develop regulatory policies aimed at reducing the impact of plastic pollution on the ecosystem and human health.

Presenting Author: Anandu Nair Gopakumar University of Missouri-Columbia

Presenting Author Biography: Anandu Nair Gopakumar is a PhD candidate in Environmental Engineering at the Department of Civil and Environmental Engineering, University of Missouri-Columbia. He holds a Bachelor's degree in Polymer Engineering and a Master's degree in Materials Engineering, with a strong emphasis on environmentally relevant research. Anandu's notable publication, "Development of Crosslinked Polyvinyl Alcohol Nanofibrous Membrane for Microplastic Removal from Water," was featured in the Journal of Applied Polymer Science as part of his PhD research. Anandu's research centres on the formation, transport, and mitigation of micro and nanoplastics in the environment. His work has been recognized by the American Water Works Association Missouri Chapter, which awarded him the MO-AWWA Popalisky Scholarship for 2024.

Authors:

Anandu Nair Gopakumar University of Missouri-Columbia
Alexander Ccanccapa-Cartagena University of Missouri-Columbia
Maryam Salehi University of Missouri-Columbia