The widespread use of plastics in industry in recent years has resulted in a sudden increase in the presence of primary and secondary microplastics in the environment. Plastics occur in the environment at concentrations in the ng and µg/L range. During the degradation process, plastics transform into µg- and ng-sized materials. Such particles can enter the body, for example, through inhalation, ingestion, or skin contact. Such small particles can penetrate the lung alveoli and even cross the blood-brain barrier. Therefore, testing for the presence and determination of microplastic concentrations in the environment is an essential element in monitoring the presence of micropollutants in the environment. The aim of this study was to investigate the adsorption process of selected micropollutants on the surface of plastics floating on the ocean surface off the coast of China. The resulting adsorbents were produced using polyethylene and polypropylene. Microplastics separated from sewage sludge containing various microplastic admixtures, including polyethylene and polypropylene, were also used as adsorbents. The adsorbates tested included micropollutants from the pharmaceutical and endocrine compounds groups. The concentration of micropollutants before and after adsorption was measured using ultra performance liquid chromatography (UPLC) coupled with tandem mass spectrometry.