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| Autor: | Hui-Ting Zhou, 周惠婷 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 Alkyl p-hydroxybenzoates, also known as parabens, was added in cosmetic, pharmaceutical and food as preservative since the 20th century. Because of its odorless, low prices and difficult hardening, they have widely been used by various applications. Recent studies have concluded that parabens might disrupt the endocrine system, affect funtions of human reproductive systems, and are classified as a potential endocrine disrupter. Therefore, it is important to develop a method to analyze paranbens in human urine. This study demonstrates an efficient, less solvent used, eco-friendly and rapid analysis method for the determination of parabens in human urine. The method involved the use of ultrasound-assisted emulsification microextection (USAEME) coupled with on-line derivatization GC-MS or UHPLC-QTOF-MS. The parameters of extaction method were optimized by Box-Behnken design and analysis of variance. The optimal conditions of USAEME were: after hydrolysis of 1 mL urine sample, 200 μL ethyl acetate (as an extractant) rapid injected into urine containing 0.1 g of sodium chloride in a conical bottom tube. After ultrasonication for 1 min and centrifugation at 7000 rpm for 10 min, the upper layer was taken and dried under nitrogen and reconsitituted with methanol. For using GC-MS analysis, a fraction of 10 μL was mixed with 1.0 μL acetic anhydride reagent and directly injected to GC-MS system to obtain on-line derivatization. For using UHPLC-QTOF-MS analysis, a fraction of 2 μL was directly injected into UHPLC system.. The detection limits with GC-MS was 0.01 - 0.02 ng/mL. Intra-day and inter-days precision (% RSD) for four analytes were less than 8 %; the detection limits with UHPLC-QTOF-MS was 0.12-0.25 ng/mL, the RSD for nine analytes were less than 10 %, indicated that these methods show a good stability and reproducibility. In real samples, MeP、EtP、PrP and BuP were detected in most urine samples by GC-MS, the total concentrations ranged from 0.3 to 124.5 ng/mL for male; and from 27.6 to 246.8 ng/mL for female. Female urine samples showed higher total concentrations for the four target parabens, which may indicate higher exposure due to lifestyle. Moreover, small amount of PeP and HxP was detected in one urine sample by UHPLC-QTOF-MS, this results indicate that some disabled and higher toxicity parabens were in use in Taiwan. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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