以綠色化學觀點發展超音波輔助乳化微萃取法來分析水樣中的有機氯農藥

The perspective of Green Chemistry on developing liquid phase microextraction based on ultrasound-assisted emulsification method for analysis of organochlorine pesticides in aqueous samples

魏碩揚(Shuo-Yang Wei)

指導教授 ： 黃賢達

國立清華大學/理學院/化學系/碩士(2011年)

摘要

近年來環保問題被視為重要的課題，因此發展對環境友善的綠色化學分析技術為永續經營的重要目的。本實驗以綠色化學觀點發展超音波輔助乳化微萃取法來分析水樣中的有機氯農藥(The perspective of Green Chemistry on developing liquid phase microextraction based on ultrasound-assisted emulsification method for analysis of organochlorine pesticides in aqueous samples)，有機氯農藥已禁用三十餘年，但由於揮發性低且不容易降解，至今仍有一定濃度的有機氯農藥殘留在環境中，經由食物鏈以及生物累積而使得人體受到危害，而一般傳統方法需要大量且毒性較高的溶劑進行萃取，過程費時又會造成環境污染。本實驗採用較低毒性萃取溶劑並減少用量即能達到萃取效果。僅使用10μL的低毒性溶劑正葵醇(1-decanol)，在不使用分散劑情況下利用超音波來增加萃取效率，分析水樣中微量的有機氯農藥。另外我們研究了離心管在超音波中水平與鉛直方向以及在水浴槽中的相對位置對於萃取效率的影響，並搭配使用改善溶劑收集系統使得萃取溶劑能夠較方便、快速的回收。在最佳化的條件下，線性範圍為 5-10000 ngL-1，偵測極限為0.6-2.9 ngL-1，濃縮倍率介於 1202-4587之間；而海水及農業用水的相對回收率分別是 75-107 %和 70-99 %。實驗證明能確實減少溶劑使用量以及有良好的濃縮倍率和回收率，為簡單快速、低成本、操作方便的新穎綠色分析方法。

關鍵字

超音波輔助乳化微萃取法 ； 液相微萃取法 ； 手搖 ； 有機氯農藥 ； 改善溶劑收集系統 ； 氣相層析儀

並列摘要

A novel sample preparation method “Dispersive liquid-liquid microextraction” (DLLME) coupled with gas chromatography–electron capture detector (GC-ECD) was developed for the analysis of organochlorine pesticides (OCPs) in aqueous samples. DLLME is a convenient and simple sample preparation method. In the study, the organochlorine pesticides consisted of lidane, heptachlor, α-endosulfan, o,p’-DDD, endrin, dieldrin, p,p’-DDE and aldrin. The procedure doesn’t need any dispersive solvent. Only the less toxic 1-decanol was used as extraction solvent, and using handshaking and ultrasound-assisted emulsification method to extract analytes. Handshaking before ultrasound-assisted emulsification is essential for effective extraction. Ultrasound was applied to accelerate the emulsification of organic solvent in aqueous solutions. It can enhance the extraction efficiency. We also aim to study the effect of horizontal and vertical directions and different sites in Ultrasonic bath. Then, we used improved solvent collection system (ISCS) to reduce the amount of extraction solvent using. After centrifugation, 1 µL of extraction solvent was injected into GC-ECD. Under the optimum conditions, the results indicate that linear range of the method was 5-2500 ngL-1 for the most of the OCPs and the LODs of method ranged from 0.6 to 2.9 ngL-1.The relative recoveries ranged from 75% to 107% for sea water and from 70% to 99% for field water. Good enrichment factor and minimization the consuming of organic solvent were obtained. The method provides a rapid, simple and environmental friendly procedure for determining OCPs in aqueous samples.

並列關鍵字

Handshaking ； Ultrasound-assisted emulsification ； Dispersive liquid-liquid microextraction ； Organochlorine pesticides ； Gas chromatography ； improved solvent collection system

參考文獻

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