Study on the Quantitative Analysis of Styrene Oligomers Originated from Styrene-based Plastic Polymer Materials

Plastic pollution is an important issue in the environment. However, there are few systematic studies on the harmful substances that can be leached out from plastics. The objective of this study is to improve a method for monitoring various styrene oligomers (SOs) derived from polystyrene (PS), one of the major plastics. To achieve this goal, in this study, extraction and concentration methods were modified to reduce the analysis time and to improve the convenience of the analysis procedure. In addition, this study selected a more appropriate internal standards (IS) for quantitative monitoring of SOs. Through a series of experiments, Acenaphthene-d10 (Ace-d10) was the most appropriate IS to quantify styrene monomer (SM). Phenanthrene-d10 (Phe-d10) was an appropriate IS for 1,3-diphenyl propane (SD-1), 2,4-diphenyl-1-butene (SD-3), trans-1,2-diphenyl cyclobutane (SD-4), and 2,4,6-triphenyl-1-hexene (ST-1). In addition, 4-Terphenyl-d14 (4-ter-d14) was appropriate as an IS for monitoring 1a-phenyl-4e-(1'-phenylethyl)tetralin (ST-3), 1e-phenyl-4e-(1'-phenylethyl)tetralin (ST-5) and 1,3,5-triphenylcyclohexane-Isomer mix (A Isomer mixture of 1e,3e,5a-triphenylcyclohexane and 1e,3e,5e-triphenylcyclohexane, ST-6mix). Recovery tests were conducted to verify selected ISs, which ranged from 80% to 120%. Then, improved SOs analysis method was applied to the seawater and sand samples of Jeju Island coast to measure SOs. This study is expected to contribute to the assessment of the impact of PS plastic contamination in the environment. Key words: Plastic pollution, Plastic debris, Polystyrene, Styrene Oligomers, Microplastic