Analysis of microplastics-sorbed endocrine-disrupting compounds in pellets and microplastic fragments from beaches

Abstract

Microplastics present in marine ecosystems have become a major environmental issue. This problem is due to not only the harmful effects of microplastics on exposed organisms, but also to their ability to adsorb organic compounds, which can have a combined harmful effect. Steroid hormones are an important group of endocrine-disrupting compounds that display moderately lipophilic behavior and can, subsequently, be adsorbed on microplastics. For this reason, it is necessary to determine this type of contaminants adsorbed on microplastic waste.

In order to investigate this issue, this work presents an analytical method based on ultrasound-assisted extraction and ultrahigh performance liquid chromatography tandem mass spectrometry (UAE-UHPLC-MS/MS) to determine the presence of 13 steroid hormones adsorbed on pellets and microplastic fragments. The different variables affecting the extraction process, such as solvent volume and extraction time, were optimized. The method showed excellent recoveries (above 80% for most compounds), satisfactory repeatability values and limits of detection (LoD) between 0.07 and 27.5 ng·g−1. Once optimized, the developed method was applied to the microplastic fragment samples and pellets collected from eight different beaches on the Canary Islands (Spain). In most samples, at least one hormone was detected and up to seven different steroid hormones in some samples. The steroid hormone concentrations in the studied samples ranged from < LoQ to 157 ng·g−1.