Determination of estrogenic hormones in environmental water samples in Vaal region by Ultra Fast Liquid Chromatography coupled to Mass Spectrometry

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Dissertation_Sibusiso Mnguni(Final Review_Submission ).pdf (2.74 MB)
Date
2016
Authors
Mnguni, Sibusiso Blessing
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Abstract
The presence of estrogenic hormones in the environment has been a subject of concern in recent years; they have been classified as “emerging pollutants” and may pose a potential risk for human consumption. Hormones have been detected in ground and surface water at low concentrations. These compounds contaminate the surface and ground water via waste water treatment plants (WWTP) and may elicit endocrine disruption to organisms. Because these compounds are available at low concentration, robust analytical methods are required to quantify these compounds in water and environmental samples. The common method for the analysis of hormones in water samples is Gas Chromatography (GC) coupled to Mass Spectrometer (MS). The challenge with GC-MS is the required lengthy derivatisation step that involves toxic chemicals. The first part of this case study was to develop a method to determine trace concentrations of the Estrone (E1), 17α-Estradiol (E2α), 17 β-Estradiol (E2β) and 17α-Ethinylestradiol (EE2) hormones using Ultra-Fast Liquid Chromatography Mass Spectrometry (UFLC-MS-MS). Using the developed method, the second part of the case study was to determine the concentrations of the hormones in raw and potable water samples from the Vaal River catchment area in the South of Johannesburg, South Africa. Analytes were extracted by solid phase extraction (SPE C18 Sorbent, 200 mg/6mℓ cartridges) and subjected to Ultra-Fast Liquid Chromatography coupled to Mass Spectrometer (UFLC-MS-MS) for identification and quantification. Optimum SPE parameters were 1000 mℓ of sample percolated, at flow rate of 10 mℓ/min, sample pH of above 7, 7.5 mℓ of methanol as elution solvent followed by solvent reduction to 250 μℓ. The limits of quantification were in a range of 0.24 to 0.32 ng/ℓ for all analytes. Accuracy was 95.6, 93.8, 97.6 and 100.9% for 17α-Ethinylestradiol, 17α-Estradiol, 17β-Estradiol and estrone, respectively. In raw water samples taken during the rainy wet season, estrone was detected at concentrations of 0.90 and 4.43 ng/ℓ. However, drinking water samples no presence of hormones with the exception of M-B12 sample point where the estrone amount of 2.88 ng/ℓ was detected. This is potentially due to fact that conventional water treatment plants are able to remove the compounds during water purification process depending on the concentration levels.
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A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 2016.
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Mnguni, Sibusiso Blessing (2016) Determination of estrogenichormones in environmental water samples in Vaal region by Ultra Fast Liquid Chromatography coupled to Mass Spectrometry, University of Witwatersrand, Johannesburg, <http://wiredspace.wits.ac.za/handle/10539/21720>
Mnguni, Sibusiso Blessing (2016) Determination of estrogenic hormones in environmental water samples in Vaal region by Ultra Fast Liquid Chromatography coupled to Mass Spectrometry, University of Witwatersrand, Johannesburg, <http://wiredspace.wits.ac.za/handle/10539/21720>
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http://hdl.handle.net/10539/21720
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