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Multiphase partitioning of endocrine-disrupting chemicals (EDCs) in the Pearl River (China) were investigated. The colloidal concentrations for 4-tert-octylphenol, 4-nonylphenol, bisphenol A (BPA), and estrone (E1) were in the ranges of 0.2 ng/L to 0.8 ng/L, 23.2 ng/L to 108 ng/L, 2.3 ng/L to 97.6 ng/L, and not detectable (nd) to 0.32 ng/L, respectively; for truly dissolved concentrations, the ranges were 0.5 ng/L to 5.4 ng/L, 39 ng/L to 319 ng/L, 13.7 ng/L to 91.2 ng/L, and nd to 1.2 ng/L, respectively. Positive correlations of EDCs with colloidal organic carbon (COC) were observed. The in situ COC normalized partitioning coefficients (log KCOC) for 4-tert-octylphenol (5.35 ± 0.42), 4-nonylphenol (5.69 ± 0.50), and BPA (5.51 ± 0.77) were within the ranges reported by other studies, whereas they were 1 to 2 orders of magnitude higher than their particulate/truly dissolved phase partition coefficients (log [ABSTRACT FROM AUTHOR]

The distribution of endocrine-disrupting chemicals (EDCs) and its relationship with dissolved and particulate organic carbon (DOC and POC) was investigated in selected rivers of the Pearl River Delta, South China. The aqueous concentrations (average; ng/L) and particulate concentrations (average; ng/g, dry wt) for 4- tert-octylphenol (OP), 4-nonylphenol (NP), bisphenol A (BPA), and estrone (E1) were in the ranges of not detectable to 153 (31.8), 276 to 2,457 (1,178), 8.4 to 628 (161), and less than 1.5 to 11.5 (3.2), respectively, and 4.4 to 402 (98.1), 342 to 12,053 (4,922), 12.3 to 758 (128), and not detectable to 14.4, respectively. The highly significant correlation of EDCs with DOC and POC, and the similar regression slopes, implied the critical importance of DOC and POC on the distribution, transport, and fate of EDCs in the aquatic environment. The in situ particle-water partition coefficients (log KOC) for OP (4.89 ± 0.41), NP (5.05 ± 0.33), and BPA (4.34 ± 0.50) were close to those reported by other field studies, but one to two orders of magnitude higher than those predicted with n-octanol-water partition coefficient ( KOW). The higher KOC values were attributed to the combined effects of low EDC concentrations, nonlinear sorption, and heterogeneity of POC and DOC. Moreover, a regression between in-situ KOC and KOW for phenolic xenoestrogens was observed (log KOC = 0.625 × log KOW + 2.28, r2 = 0.99), suggesting that hydrophobicity contributed predominantly to the overall sorption of OP, NP, and BPA. Environ. Toxicol. Chem. 2012; 31: 2456-2464. © 2012 SETAC [ABSTRACT FROM AUTHOR]

Abstract: The occurrence of alkylphenols (APs) including nonylphenol (NP) and octylphenol (OP) in the riverine sediments from the Pearl River Delta (PRD), South China was investigated and compared by Soxhlet extraction (S-APs) with dichloromethane and by sequential accelerated solvent extraction (ASE) (A-APs) with 1:6 toluene/methanol, respectively. Concentrations of OP and NP range from <1 to 463ng/gdw and 31–21,885ng/gdw, respectively, demonstrating that the contamination level of APs in the PRD is one of the highest in the world. Moreover, the A-APs contents are highly significantly related to and on average 1.5 times the S-APs contents. For sequential two ASE extractions, APs in the first extract accounts for 82.2–99.2% of their total contents in the sequential two extractions. The correlation analysis shows that S-APs and A-APs are both significantly associated with the contents of total organic carbon (TOC), suggesting that the variable extraction efficiency of these two methods is related to the presence of condensed organic matter in the sediments. [Copyright &y& Elsevier]