Environ Toxicol Chem. 2013 Dec;32(12):2755-61. doi: 10.1002/etc.2360.
Because of large usage as flame retardants and additives, organophosphate esters (OPEs) are widely detected in the environment and regarded as emerging contaminants. However, the sorption of OPEs to organic matter and its effects have scarcely been studied. In the present study, the sorption of 9 commonly used OPEs to 4 representative humic acids--Elliott Soil humic acid, Suwannee River humic acid, Aldrich humic acid, and Acros humic acid--in the range of 0 mg/L to 50 mg/L dissolved organic carbon (DOC), was evaluated with negligible-depletion solid-phase microextraction and verified by its impacts on the toxicity to the aquatic invertebrate Daphnia magna. Whereas OPEs with a high octanol/water partition coefficient (log K(OW)=4.51-6.64) were associated with humic acids mainly by hydrophobic interaction with DOC partition coefficient (K(DOC)) in the range of 10²·²² to 10⁵·³¹, the sorption of low-K(OW) OPEs (log K(OW)=-0.65 to 2.59) to humic acids was not hydrophobic interaction-dominant, with K(DOC) in the range of 10³·⁴⁷ to 10⁴·²⁹. These results were corroborated by the effects of humic acids on the acute toxicity of 3 high-K(OW) OPEs to D. magna. The sorption of OPEs to Suwannee River humic acid was weak and had negligible effects on the toxicity of high-K(OW) OPEs; the presence of terrestrial Acros humic acid (50 mg/L DOC), however, significantly decreased the toxicity by 53% to 60%. The results indicated that the strong sorption between high-K(OW) OPEs and terrestrial humic acid might affect their transportation and bioavailability.
由于作为阻燃剂和添加剂的大量使用，有机磷酸酯（OPEs）广泛存在于环境中，被认为是新兴污染物。然而，OPEs 与有机物的吸附及其影响很少被研究。在本研究中，通过微固相萃取和对水生无脊椎动物大型溞急性毒性的影响，评估了在 0-50 mg/L 溶解有机碳（DOC）范围内，9 种常用 OPEs 对 4 种代表性腐殖酸（Elliott 土壤腐殖酸、苏万尼河腐殖酸、Aldrich 腐殖酸和 Acros 腐殖酸）的吸附作用。具有高辛醇/水分配系数（log K(OW)=4.51-6.64）的 OPEs 主要通过与 DOC 分配系数（K(DOC)）的疏水相互作用与腐殖酸结合（10²·²²-10⁵·³¹），而低 K(OW) OPEs（log K(OW)=-0.65-2.59）对腐殖酸的吸附则不是以疏水相互作用为主，K(DOC)在 10³·⁴⁷-10⁴·²⁹之间。这些结果得到了腐殖酸对 3 种高 K(OW) OPEs 对大型溞急性毒性影响的验证。OPEs 与苏万尼河腐殖酸的吸附较弱，对高 K(OW) OPEs 的毒性影响可以忽略不计；然而，陆地 Acros 腐殖酸（50 mg/L DOC）的存在显著降低了毒性，降低了 53%-60%。结果表明，高 K(OW) OPEs 与陆地腐殖酸之间的强吸附作用可能会影响它们的迁移和生物利用度。
