Flower-like molybdenum disulfide/cobalt ferrite composite for the extraction of benzotriazole UV stabilizers in environmental samples

Benzotriazole UV stabilizers (BUVSs) are a class of emerging contaminants of concern; the development of rapid and convenient monitoring method for these trace-level pollutants in waters is of crucial significance in environmental science. Here, a novel magnetic flower-like molybdenum disulfide/cobalt ferrite nanocomposite (MoS 2 /CoFe 2 O 4 ) was synthesized by hydrothermal reaction. Compared with the conventional Fe 3 O 4 -based magnetic composites, the proposed material just required a minimum consumption of Co/Fe towards the equivalent of MoS 2 while providing superior magnetization performance. Taking advantages of high adsorption capacity, extraordinary stability, and repeatability in construction, MoS 2 /CoFe 2 O 4 was applied to the extraction to BUVSs. The enrichment factors of three BUVSs were in the range 164–193 when 20 mL of environmental water sample was loaded on 40 mg of the adsorbent. MoS 2 /CoFe 2 O 4 could be regenerated and recycled at least 10 cycles of adsorption/desorption with recoveries of 80.1–111%. The method of MoS 2 /CoFe 2 O 4 -based extraction coupled with high-performance liquid chromatography-variable wavelength detector was applied to the monitoring of BUVSs in seawater, lake water, and wastewater, which gave detection limits ( S/N  = 3) of 0.023–0.030 ng·mL −1 and recoveries of 80.1–110%. The intra-day and inter-day precisions (relative standard deviation, RSDs, n  = 3) were in the range 1.6–7.5% and 3.2–11.5%, respectively. The approach is an alternative for efficient and sensitive extraction and determination of trace-level environmental pollutants in waters. Graphical Abstract