利用低毒性分散液液微萃取法分析水樣中的微量有機化合物

Low toxic dispersive liquid-liquid microextraction for extraction of trace organic compounds in water samples

梁美怡(Leong, Mei I)

指導教授 ： 黃賢達

國立清華大學/理學院/化學系/博士(2013年)

https://doi.org/10.6843/NTHU.2013.00383

摘要

液液微萃取法 (Liquid phase microextraction, LPME) 常被應用在環境樣品的萃取分析上，本文主要介紹三個結合簡單、快速及低毒性三大優點的液液微萃取法如何被應用在萃取水樣中的微量有機化合物。
分散液液微萃取法 (Dispersive liquid-liquid microextraction, DLLME) 具有快速、低成本及高濃縮效果的優點，可是由於它所使用的萃取溶劑毒性較高，對環境不利，因此，本文發展了各種新的微萃取方法去克服以上的問題。本文第二章為利用冷凝分散液液微萃取法 (Dispersive liquid-liquid microextraction base on the solidification of a floating organic droplet, DLLME-SFO) 萃取水樣裏的含鹵素的有機化合物 (Halogenated organic compounds, HOCs) ，水樣與萃取溶劑間大的接觸面積大大加強了分析物被萃取的機率，同時亦縮短了分析物被萃取的時間；第三章為利用DLLME-SFO分析水樣裏的有機氯化合物 (Organochlorine pesticides, OCPs) ，此方法使用了較低毒的萃取溶劑及較低量的分散溶劑進行萃取；第四章為利用低毒性液液微萃取法 (Low toxic-dispersive liquid-liquid microextraction, LT-DLLME) 分析水樣中的多環芳香烴 (Polycyclic aromatic hydrocarbons, PAHs) ，此方法比對了過去常用的含氯萃取溶劑與本次實驗新測試的十三種含溴及含碘的萃取溶劑的萃取效果；第五章為利用超音波輔助微萃取法 (Ultrasound-assisted emulsification microextraction , USAEME) 分析水樣中的揮發性有機化合物(Volatile organic compounds, VOCs)，此方法避免了使用分散溶劑，大大降低了整體的有機溶劑使用量。
以上四個實驗主要是利用低毒性的有機溶劑取代過去常被用在DLLME的高毒性萃取溶劑，其中第二章及第三章是使用密度比水低的低毒性長碳鍵有機溶劑，而第四及第五章是利用密度較水高的低毒性含鹵素的有機溶劑。這四個實驗的結果均顯示這些方法對於萃取水樣中微量的有機化合物是非常合適及可以達到ppb或ppt的效果。

關鍵字

液液微萃取法

並列摘要

Liquid-liquid microextraction (LPME) is usually applied in extraction of environmental samples. In this thesis, three simple, rapid and low toxicity liquid-liquid microextraction methods have been developed for the extraction and analysis of trace organic compounds in water samples.
Dispersive liquid-liquid microextraction (DLLME) was introduced by Rezaee et al. and coworkers. The advantages of DLLME are rapidity, low cost and high enrichment factor. However, the high-toxic extraction solvents used are environment-unfriendly. To solve the aforementioned problems, three extraction methods were introduced in this thesis. The first topic in this thesis describes a DLLME method base on the solidification of a floating organic droplet (DLLME-SFO). This method combined with gas chromatography with electron-capture or mass spectrometry to analyze five halogenated organic compounds (HOCs). The large contact surface between the sample and the droplets of extractants speeds up mass transfer and shorter extraction time. Second topic describes the extraction of organochlorine pesticides (OCPs) in water samples by using DLLME-SFO method. This method used less disperser solvent (200 µL) than the previously reported DLLME-SFO method (500 -1000 µL). The third topic describes the low toxic DLLME (LT-DLLME) using halosolvents for extraction of polycyclic aromatic hydrocarbons in water samples, we compared the extraction efficiency of five chlorosolvents and thirteen bromo/iodo solvents, these halosolvents were applied for the first time in DLLME method. The fourth topic describes the determination of volatile organic compounds (VOCs) in water using ultrasound-assisted emulsification microextraction (USAEME) followed by gas chromatography, this method avoids using the disperser solvent, decreasing the price and the exposure of the operators to toxic extraction solvent.
In the first two topics (DLLME-SFO), the floated extractant is solidified and is easily collected for analysis. In addition, this method is no need to use conical bottom glass tubes. The last two topics used high density extraction solvent, less toxicity solvent such as 1-bromo-3-methylbutane and 1-bromooctane to instead of the high toxic solvent which was normally used in DLLME. The results of these four experiments showed that these sample preparation techniques coupled with gas chromatography detection could determinate the trace organic pollutants in the low ppb or ppt level.

並列關鍵字

microextraction ； Dispersive liquid-liquid microextraction

參考文獻

[64] http://toxipedia.org/display/toxipedia/Polycyclic+Aromatic+Hydrocarbons

[1] D. Puig, D. Barcelo, Trends Anal. Chem. 15 (1996) 362

[2] M.T. Kelly, M. Larroque, J. Chromatogr. A 841 (1999) 177.

[3] S. Magdic, J.B. Pawliszyn, J. Chromatogr. A 723 (1996) 111.

[5] Y. He, A. Vargas, Y.J. Kang, Anal. Chim. Acta 589 (2007) 225.