Environ. Sci. Technol. 2005, 39, 2753-2761
Partition of Endocrine-Disrupting Chemicals between Colloids and Dissolved Phase As Determined by Cross-Flow Ultrafiltration RUIXIA LIU, ANDREW WILDING, ANDREW HIBBERD, AND JOHN L. ZHOU* Department of Biology and Enviromental Science, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, U.K.
Cross-flow ultrafiltration (CFUF) was developed first for the isolation of natural colloids and subsequently for determining the partition of selected endocrine-disrupting chemicals (EDCs) between river colloids and dissolved phase. In this study, a 1-kDa Millipore Pellicon 2 cartridge type CFUF system was validated using a range of molecular probes spiked in natural waters. Results show that good retention (>80%) of high molecular weight (HMW, >1 kDa) molecules and low retention of low molecular weight (LMW, 5 d, sodium azide was added to a final concentration of 0.05% to prevent potential biodegradation of EDCs. Table 3 presents the concentration ratio (Cr/Cp) of the chosen compounds in retentates and permeates operated by CFUF system after different contact times between EDCs and colloids. A decreasing trend in Cr/Cp value was found with increasing time for the more hydrophobic compounds such as 4-tert-octylphenol and 4-nonylphenol from 4.3 and 15.9 at 5 min to
