Identification of EDCs in drinking water treatment
Date Issued
2009
Date
2009
Author(s)
Chen, Jia-Jhen
Abstract
This thesis focus on solid-phase extraction (SPE) and two detection methods of Endocrine Disrupting Chemicals (EDCs), i.e. enzyme -linked immunosorbent assay (ELISA/EIA) and high-performanceliquid chromatography (HPLC), in water treatment processes. The ELISA / EIA is a fast and reliable detection method. Comparison of two commercial estradiol ELISA kits, i.e. ‘Cayman’ and ‘wako’, are made in this study. The results show that the detection limit and accuracy of Cayman Kit is better than Wako Kit. The HPLC connected ultra-violet light (HPLC-UV) is used to qualitatively and quantitatively detect nonylphenol and bisphenol A in various unit process of water treatment plants. Both chemicals achieve good linear relationships (R square value are both higher than 0.995). The limit of detection (LOD) of Nonylphenol and bisphenol A are determined as 0.68ppm and 0.15ppm. In order to determine the best light source of detecting estradiol, bisphenol A and nonylphenol, the HPLC-UV and fluorescence excitation and absorption (EEM) are used to compare their absorption spectras. The results indicate that EEM is significantly better than the UV light source (ppm level, R saqure value more than 0.8) in terms of accuracy and the sensitivity (ppb level, R square value more than 0.995). SPE method is a common method for concentration trace target analysts. The concentration ratio, types of organic solvents and effects of various extraction steps of on the recovery of (estradiol, bisphenol A and nonylphenol) are addressed. In the organic solvent comparison, DMSO shows better recovery (81%) than methanol (71%). At the high concentration ratios, the concentration ratio increase from 5000~50000 times and the recovery rate decrease from 106.1% to 56.43%. In the comparison of SPE procedures, recovery 91.7% obtained in previous protocol (RJ Wong, 2008) are experimentally verified higher than those in the other literature (78.03%). With regard to natural water analysis of all process units in two water treatment plants (Changhsing and Jhihtan WTP), the analysis ranges of natural estrogen and testosterone are from not detected (ND) to 9ng‧L-1. water are detected in the range between ND to 0.5ppb.
Subjects
EDCs, Endocrine Disrupting Chemicals
estradiol
ELISA
nonylphenol
Type
thesis
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