Endocrine disrupting chemicals (EDC) are exogenous substances that can potentially mimic hormonal substances and cause adverse effects on the endocrine system of living beings. The behavior and fate of these compounds in the environment is directly related to their physical-chemical properties, which indicate great affinity for solid and organic particles and suggest an inherent mechanism of fractionation between dissolved and particulate phases of aqueous matrices. However, few studies have been considering this fact when quantifying these pollutants and their effects through bioassays. In this study, the fractionation of estrogenic substances between dissolved and particulate phases in an urban stream was investigated via estrogenic activity evaluation by the YES assay. Two fractions of suspended solids (< 0.7 µm and between 0.45 and 0.7 µm) and the dissolved phase were considered and two approaches of SPE percolations were applied. Total estradiol equivalent (E2-Eq) values were observed in the 29–65 ng L⁻¹ range, of which 35–62% were associated with the particulate phase. Most of the estrogenicity was associated with particles between 0.45 and 0.7 µm, whereas cytotoxicity was induced by extracts of particles greater than 0.7 µm. Results demonstrated the importance of solid fractions analysis towards the quantification of total estrogenic activity from aqueous environmental matrices and highlights the relevance of controlling fine suspended solids in sewage treatment plant effluents, regarding the control of endocrine disrupters in the environment.

内分泌干​​扰化学物质（EDC）是外源物质，可以潜在地模仿激素物质，并对生物体的内分泌系统产生不利影响。这些化合物在环境中的行为和命运与它们的物理化学性质直接相关，这表明它们对固体和有机颗粒具有很高的亲和力，并暗示了水性基质的溶解相和颗粒相之间进行分馏的内在机理。但是，很少有研究在通过生物测定量化这些污染物及其影响时考虑到这一事实。在这项研究中，通过YES分析法通过雌激素活性评估研究了城市河流中溶解相和颗粒相之间的雌激素物质的分馏。悬浮固体分为两部分（<0.7 µm，在0.45和0之间。考虑了7 µm）和溶解相，并采用了两种SPE渗滤方法。在29–65 ng L中观察到总雌二醇当量（E2-Eq）值^-1范围，其中35–62％与颗粒相有关。大多数雌激素与0.45至0.7 µm的颗粒有关，而大于0.7 µm的颗粒提取物则引起细胞毒性。结果证明了固体成分分析对定量测定水性环境基质中总雌激素活性的重要性，并强调了在控制环境中内分泌干扰物方面，控制污水处理厂废水中细悬浮固体的重要性。