| DC 欄位 |
值 |
語言 |
| DC.contributor | 化學學系 | zh_TW |
| DC.creator | 吳信宏 | zh_TW |
| DC.creator | Hsin-hung Wu | en_US |
| dc.date.accessioned | 2008-6-30T07:39:07Z | |
| dc.date.available | 2008-6-30T07:39:07Z | |
| dc.date.issued | 2008 | |
| dc.identifier.uri | http://ir.lib.ncu.edu.tw:444/thesis/view_etd.asp?URN=952203005 | |
| dc.contributor.department | 化學學系 | zh_TW |
| DC.description | 國立中央大學 | zh_TW |
| DC.description | National Central University | en_US |
| dc.description.abstract | 六溴環十二烷(Hexabromocyclododecanes, HBCDs)是商業上主要使用的一種非芳香族溴化環烷耐燃劑，常見添加於發泡聚苯乙烯(EPS)、擠塑聚苯乙烯(XPS)或高抗衝擊級聚苯乙烯(HIPS)等塑料中，作為建築防火材料、家俱與紡織塑料或電子商品等用途。因為六溴環十二烷具有價格便宜、阻燃效果佳的特性，在多溴二苯醚(Polybromodiphenyl ethers, PBDEs)近年來逐漸受各國法規限制而禁用下，成為取代多溴二苯醚的最佳選擇。但近年來研究發現六溴環十二烷不但會影響甲狀腺及賀爾蒙內分泌系統，甚至有致癌的可能性，加上六溴環十二烷具有生物累積(Bioaccumulation)及生物放大(Bioconcentration)效應，如果釋放到環境中，其持久性亦會對環境與人體健康造成傷害。而商業上之六溴環十二烷又依其立體結構上的不同，主要存在有α、β及γ三種構型。
以往相關於環境中六溴環十二烷的研究多以索氏萃取法(Soxhletextraction, SE)居多，但鑒於此方法在時間與溶劑使用上的浪費，近年來加壓溶液萃取法(Pressurized liquid extraction, PLE)的發展改善了這些問題，但受限於樣品通量太低而使實驗效率受到限制，因此微波輔助萃取法(Microwave assisted extraction, MAE)已成為近年來面對固態樣品中含有之環境汙染物時，新興且有效率的萃取方法，但在已知文獻中卻尚無微波輔助萃取法於六溴環十二烷檢測之應用，因此本研究將嘗試運用以微波輔助萃取法，開發一套針對環境底泥與生物檢體中六溴環十二烷檢測方法。
在本研究中，我們將六溴環十二烷運用微波輔助萃取時的參數(如；萃取溶劑組成、萃取溫度與萃取時間等)，做系統性的研究並使參數最佳化。透過高效能液相層析儀(High performance liquid chromatography, HPLC)的幫助，使六溴環十二烷之三種立體異構物能夠完全分離，並在搭配電灑游離介面(Electrospray ionization, ESI)於負離子偵測模式下，分別進入質譜儀(Mass spectrometry, MS) 進而進行定性與定量的檢測。
微波輔助萃取法在最佳化實驗參數下，以40 mL的丙酮：正己烷(1:3, v/v)作為萃取溶劑，在90℃下對5 g 的樣品萃取12 分鐘能得到最佳實驗結果；而在底泥樣品的萃取回收率實驗中，其回收率在51 %至98 %間，相對標準偏差在0.7 %至20.1 %之間；而定量極限(Limit of quantification, LOQ)則可達到30 至40 pg/g。之後，我們將微波輔助萃取法所得結果，與傳統索式萃取法及加壓溶劑萃取法所得結果做一討論。由數據顯示，微波輔助萃取方法對六溴環十二烷之應用不但具有良好的準確度與精確度，同時並可對魚體及底泥檢體中所含有之微量六溴環十二烷做一有效確認。 | zh_TW |
| dc.description.abstract | Hexabromocyclododecanes (HBCDs) is a nonaromatic brominated cyclic alkane which is widely used brominated flame retardants in the markets. HBCDs are used primarily as an additive in thermoplastic ploymers with final applications in styrene resins. It has also been used in textile coating, cable, latex binding and unsaturated polyesters. Since the production and applications of polybromodiphenyl ethers (PBDEs) have been banned or restricted in many countries, due to the high capability and relatively low production cost, HBCDs could be the best alternative for PBDEs in many applications. Recent studies have shown that HBCDs has a strong tendency to be bioaccumulate and high bioconcentration factor. It is also persistent in various environmental matrices. The commercial HBCD products are composed of three diastereomers: α-, β- and γ-HBCD.
Soxhlet extraction is the widely used for extraction organics from solid samples, however, it is time and solvent consuming. Newly developed pressurized liquid extraction (PLE) method is selective and non-solvent consuming technique, but ＂one time a sample＂ sequential procedure and possible restrictor blockage are its drawbacks. Recently, microwave-assisted extraction (MAE) has been developed to extract various pollutants from solid and biological tissue samples. MAE offers high throughput and relatively low-solvent consumption.
In this study, the effects of various operating parameters (i.e., composition of extraction solution, temperatures and times) for the quantitative extraction of HBCDs by MAE were systematically investigated and optimized. Three diastereomers (α-, β- and γ-HBCD) were then completely separated and quantitated by liquid chromatography – ion trap mass spectrometry (LC-IT-MS) with electrospray (ESI) in negative ionization mode. The HBCDs can be completely extracted by 40 mL of acetone/n-hexane (1/3, v/v) at 90 ?C with 12 min of extraction. Recovery of HBCDs in spiked sediment samples ranged from 51 to 98 % with 0.7–20 % RSD. Limits of quantitation (LOQs) were established between 30 and 40 pg/g (dry weight) in 5 g of sediment sample. The extraction efficiency of the MAE was also compared with Soxhlet extraction and PLE methods.
Furthermore, the accuracy and precision of the method were performed and the effectiveness of the method for the unequivocal determination of HBCDs in fish and sediment samples at trace-level has been demonstrated. | en_US |
| DC.subject | 六溴環十二烷 | zh_TW |
| DC.subject | 微波輔助萃取 | zh_TW |
| DC.subject | 液相層析 | zh_TW |
| DC.subject | 質譜儀 | zh_TW |
| DC.subject | Hexabromocyclododecane | en_US |
| DC.subject | Ion Trap | en_US |
| DC.subject | High Performance Liquid Chromatography | en_US |
| DC.subject | Microwave-Assisted Extraction | en_US |
| DC.subject | Mass Spectrometry | en_US |
| DC.title | 以微波輔助萃取搭配液相層析質譜儀檢測固態樣品中六溴環十二烷之方法開發 | zh_TW |
| dc.language.iso | zh-TW | zh-TW |
| DC.title | Trace Determination of Hexabromocyclododecane in Sediment and Fish by Microwave-Assisted Extraction and Liquid Chromatography- Ion-Trap Mass Spectrometry | en_US |
| DC.type | 博碩士論文 | zh_TW |
| DC.type | thesis | en_US |
| DC.publisher | National Central University | en_US |