Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Characterization of microplastics in environment by thermal gravimetric analysis coupled with Fourier transform infrared spectroscopy Jianping Yu a , Pingya Wang b,1 , Fengli Ni a , James Cizdziel c , Dongxu Wu d , Qiaoling Zhao b , Ying Zhou a,e,f, ⁎ a College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China b Zhoushan Institute of Calibration and Testing for Quality and Technical Supervision, Zhoushan 316021, China c Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USA d Zhejiang Institute of Metrology, Hangzhou 310018, China e Research Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou 310014, China f Environmental Microplastic Pollution Research Center, Zhejiang University of Technology, Hangzhou 310014, China ARTICLE INFO Keywords: TGA-FTIR Microplastics Thermal analysis Mussels Seawater Soil ABSTRACT As a global pollutant, microplastics have attracted attention from the public and researchers. However, the lack of standard and time-saving methods for analysis has become one of the bottlenecks in microplastics research. Here, we demonstrate TGA coupled to FTIR to identify and quantify certain microplastics in environment. Samples were pyrolyzed in TGA and the pyrolysis gases were analyzed by FTIR. Combining TGA and FTIR data adds discriminatory power as temperature profiles and absorption spectra differ among several common plastics. To quantify on a mass basis, we calibrated on characteristic IR peaks at temperatures of maximum weight loss for individual polymers. The method can distinguish PVC, PS and was validated by spiking samples with known quantities of microplastics. The result of field sample experiments showed that TGA-FTIR can be used to identify and quantify PVC and PS in bivalves, seawater and soil. And the method may be applicable to environmental samples. 1. Introduction Microplastics is a new global pollutant, defined as plastics with a size of < 5 mm. Microplastics was first proposed by Thompson et al. (2004), and has attracted more and more attention from the scientific community and the public. They consist of primary microplastics, those manufactured to be small, including microbeads, and secondary mi- croplastics, those stemming from larger fragments that have been de- graded and broken down by long-term physical, chemical and biolo- gical effects in the environment (Zhao et al., 2015; Fendall Lisa and Sewell, 2009). Some of the more common forms of microplastics found in the environment include polyethylene (PE), polyethylene ter- ephthalate (PET), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), nylon (PA), acrylonitrile butadiene styrene plastic (ABS), copolymers, and mixtures of plastics (Eriksen et al., 2014). There is widespread distribution of microplastics in nearly all aquatic environments, especially along coastlines, including those of Japan (Mato et al., 2001), United Kingdom (Ashton et al., 2010), Portugal (Frias et al., 2010), Greece (Karapanagioti et al., 2011), and the United States (Van et al., 2012). Many freshwater lakes and rivers have also been shown to be contaminated with microplastics. Taihu Lake in China was reported to have some of the highest levels of mi- croplastics with 3.4–25.8 items per L in surface water (Su et al., 2016). Proximity to population centers, wastewater treatment plants, and in- dustry, generally increase the abundance of microplastics in nearby waters (Lechner et al., 2014). However, microplastic contamination is also present in areas that are far from these sources, including Lake Kusugur in Mongolia (Christopher et al., 2014), remote beaches of northeastern Brazil (Costa et al., 2010), and in subalpine lakes in Italy (Hannes et al., 2013). Due to their small size, microplastics are the most biologically and toxicologically relevant (Hidalgo-Ruz et al., 2012; Lonnstedt and Eklov, 2016). Microplastics are readily ingested by organisms, potentially posing a health risk to the organisms, and accumulating in the food chain (Gall and Thompson, 2015). Moreover, because of the hydro- phobic nature of some plastics, certain persistent organic pollutants, https://doi.org/10.1016/j.marpolbul.2019.05.037 Received 24 March 2019; Received in revised form 14 May 2019; Accepted 15 May 2019 ⁎ Corresponding author at: College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China. E-mail address: yingzhou@zjut.edu.cn (Y. Zhou). 1 Contributed equally to this work and will be considered as co-first authors. Marine Pollution Bulletin 145 (2019) 153–160 Available online 24 May 2019 0025-326X/ © 2019 Elsevier Ltd. All rights reserved. T