Analysis of Chemical Compounds Related to Microplastics

Microplastics (MPs) are recognized as emergent contaminants in both terrestrial and aquatic environments due to their ability to absorb and release toxic chemicals. The complex interactions that occur between synthetic MPs polymers and hydrophobic toxic compounds, metals, additives, and other emergent contaminants complicates the standardization of techniques used for the extraction and quantitation of these chemicals. Organic compounds are extracted from MPs by soaking, sonication, and the use of microwave, Soxhlet and accelerated solvent extraction (ASE) techniques in a variety of polar and nonpolar solvents. The extracts are cleaned up through solid-phase extraction (SPE) and analyzed by gas chromatography (GC) or liquid chromatography (LC) using an assortment of detectors. The analysis of metals from MPs is more standardized, usually with extraction in 20% aqua regia and analysis by inductively coupled plasma mass spectrophotometry (ICP-MS). Published papers do not consistently report the use of standards, detection levels, and other quality control measures. This chapter provides a summary of research on the chemical analysis of toxic compounds sorbed to and leached from MPs in order to better understand the chemical processes and help advance the harmonization of chemical analysis of MPs and their associated contaminants.