An alternative method for the determination of estrogens in surface water and wastewater treatment plant effluent using pre-column trimethylsilyl derivatization and gas chromatography/mass spectrometry. Environ Monit Assess
A procedure using pre-column trimethylsilyl derivatization and gas chromatography/ mass spectrometry (GC/MS) was developed and applied in determining trace estrogens in complex matrix. Main conditions were optimized, including pH value, salinity of water sample, elution reagents, clean procedure, derivative solvent and temperature. The optimized method was used to determine steroid estrogens in surface water and effluents of wastewater treatment plant (WWTP). Low detection limits of 0.01, 0.03, 0.03, 0.07, 0.09 and 0.13 ng/l for DES, E1, E2, EE2, E3 and E(V), respectively were obtained under optimism condition. No apparent interferences appeared in chromatography in comparison with ultrapure water blank. Mean recovery ranged from 72.6% to 111.0% with relative standard deviation of 1.1-4.6% for spiked surface water, and from 66.6% to 121.1% with relative standard deviation of 1.5-4.7% for spiked effluent of WWTP. The results suggested that the optimized method provides a robust solution for the determination of trace steroid estrogens in complex matrix.
"Limit of detection (LOD) and limit of quantification (LOQ) were achieved by 1,250 times concentration and 5,000 times concentration for influent and effluent from the WWTPs. They were calculated as the minimum amount of a compound present in the sample that produced a signal to noise ratio of six, based on a 1-μl aliquot injection of the final 0.4 ml extraction solution (Zhou et al. 2009). LOD and LOQ in water were 0.05–0.48 "
[Show abstract][Hide abstract] ABSTRACT: Concentration levels of six natural and anthropogenic origin steroid estrogens, namely, diethylstilbestrol (DES), estrone (E1), estradiol (E2), estriol (E3), ethinylestradiol (EE2), and estradiol-17-valerate (Ev), from different effluents in Beijing were assessed. Sampling sites include two wastewater treatment plants (WWTPs), a chemical plant, a hospital, a pharmaceutical factory, a hennery, and a fish pool. In general, concentrations of estrogens in the effluents varied from no detection (nd) to 11.1 ng/l, 0.7 to 1.2 × 10(3) ng/l, nd to 67.4 ng/l, nd to 4.1 × 10(3) ng/l, nd to 1.2 × 10(3) ng/l, and nd to 11.2 ng/l for DES, E1, E2, EE2, E3, and Ev, respectively. The concentration levels of steroid estrogens from different effluents decreased in the order of pharmaceutical factory and WWTP inlets > hospital > hennery > chemical factory > fish pool. This study indicated that natural estrogens E1, E2, and E3 and synthetic estrogen EE2 are the dominant steroid estrogens found in the different Beijing effluents. For source identification, an indicator (hE = E3/(E1 + E2 + E3)) was used to trace human estrogen excretion. Accordingly, hE in effluents from the hospital and WWTP inlets exceeded 0.4, while much smaller values were obtained for the other effluents. Human excretions were the major contributor of natural estrogens in municipal wastewater. Estimation results demonstrated that direct discharge was the major contributor of steroid estrogen pollution in receiving waters.
[Show abstract][Hide abstract] ABSTRACT: We study pulse dynamics in one-dimensional heterogeneous media. In particular we focus on the case where the pulse is close to the singularity of codim 2 type consisting of drift and saddle-node instabilities in a parameter space. We assume that the heterogeneity is of jump type, namely one of the
coefficients of the system undergoes an abrupt change at one point in the space. Depending on the height of this jump, the responses of pulse behavior are penetration, splitting, and rebound. Taking advantage of the fact that pulse is close to the singularity, the PDE dynamics can be reduced to a finite-dimensional system, which displays the three behaviors. Moreover it takes a universal form independent of model systems, and is valid for much more general heterogeneities such as bump, periodic, and random cases.
[Show abstract][Hide abstract] ABSTRACT: The occurrence of estrogens in the aquatic environment attracts increasing attention because of their strong endocrine disrupting potency. In the present work, concentrations of six estrogens including diethylstilbestrol (DES), estrone (E1), beta-estradiol (E2), estriol (E3), 17alpha-ethynylestradiol (EE2) and beta-estradiol 17-valerate (EV) in surface water and sediment sampled from three rivers in Tianjin area, northern China, were determined by gas chromatography-mass spectrometry (GC-MS). The concentrations of all six estrogens (Sigma6ES) ranged from 0.64 to 174 ng L(-1) in waters and from 0.98 to 51.6 ng g(-1) dry weight (dw) in sediments, and varied for each river. Among these estrogens, E1 was the most abundant and could be detected in all samples. DES and EV could be detected either in river water or in sediment, but in the concentration below 10 ng L(-1) and 10 ng g(-1) for water and sediment, respectively. The relationships between concentration of estrogens and organic carbon content in sediments and the relationships between sediment-water partition coefficient (logK(oc)) and octanol-water partition coefficient (logK(ow)) were examined. The results showed that the contents of the Sigma6ES correlated significantly with the contents of organic carbon (OC%). It indicated that sediments with high organic carbon were more likely to retain estrogens than those with lower organic carbon levels in the natural aquatic environment. Furthermore, the linear correlations between logK(ow) and logK(oc) were obtained for each river, which indicated that sediment-water partitioning of estrogens in three rivers could be predicted by their hydrophobic properties.
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