Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers in many products and materials. Because of the potential biologic toxicity on human beings, OPEs are regarded as a class of emerging pollutants. Dissolved organic matters (DOM) have significant effects on the bioavailability and toxicity of the pollutants in the environment. Negligible-depletion solid-phase microextraction (nd-SPME) is an efficient way for measuring the freely dissolved pollutants but suffers from long equilibrium time. Metal-organic frameworks (MOFs) are a class of porous crystalline materials with unique properties such as high pore volume, regular porosity, and tunable pore size, being widely used for the extraction of various organic compounds. Here we developed a novel method for quick determination the sorption coefficients of OPEs to DOM in aquatic phase using Fe₃O₄@MIL-100 (Fe) core-shell magnetic microspheres. The mesoporous structures of the as-synthesized microspheres hindered the extraction of OPEs which associated with humic acid due to the volume exclusion effect. However, the freely dissolved OPEs can access into the mesoporous and then were extracted by MIL-100 (Fe). Due to the small pore size (4.81 nm), large surface area (141 m² g⁻¹), high pore volume (0.17 g³ g⁻¹), and ultra-thin MOFs layers, Fe₃O₄@MIL-100 (Fe) core-shell magnetic microspheres have large contact area for the analytes in aqueous phase and therefore the diffusion distance was largely shortened. Besides, the microspheres can be collected conveniently after the extraction process by applying a magnetic field. Compared to the nd-SPME method with 35 h equilibration time (t_90%), the proposed method for these studied OPEs only need 24 min to achieve equilibration. The sorption coefficients (logK_DOC) of the OPEs to humic acid were ranged from 3.84–5.28, which were highly consistent with the results by using polyacrylate-coated fiber and polydimethylsiloxane-coated fiber with nd-SPME.

有机磷酸酯（OPEs）在许多产品和材料中被广泛用作阻燃剂和增塑剂。由于对人体具有潜在的生物毒性，因此OPE被视为一类新兴污染物。溶解性有机物（DOM）对环境中污染物的生物利用度和毒性具有重大影响。微量消耗固相微萃取（nd-SPME）是测量自由溶解污染物的有效方法，但平衡时间长。金属有机骨架（MOF）是一类多孔晶体材料，具有独特的特性，例如高孔体积，规则的孔隙率和可调的孔径，被广泛用于各种有机化合物的萃取。₃ O ₄ @ MIL-100（Fe）核-壳磁性微球。合成的微球的介孔结构由于体积排阻效应而阻碍了与腐殖酸相关的OPE的提取。但是，自由溶解的OPE可以进入中孔，然后被MIL-100（Fe）萃取。由于孔尺寸小（4.81 nm），表面积大（141 m ²  g ^-1），孔体积大（0.17 g ³  g ^-1）和超薄MOFs层，Fe ₃ O ₄@ MIL-100（Fe）核-壳磁性微球与水相中的分析物接触面积较大，因此扩散距离大大缩短。此外，在提取过程后，可以通过施加磁场方便地收集微球。与具有35 h平衡时间（t _90％）的nd-SPME方法相比，针对这些研究的OPE提出的方法仅需要24分钟即可达到平衡。OPEs对腐殖酸的吸附系数（log K _DOC）在3.84–5.28之间，这与使用聚丙烯酸酯涂层的纤维和聚二甲基硅氧烷涂层的纤维与nd-SPME的结果高度一致。