以固相微萃取法及氣相層析-質譜儀檢測水中微量之4-壬基苯酚

Abstract

壬基酚聚乙氧基醇類(nonylphenol polyethoxylate)為最常使用的非離子型界面活性劑，其在環境中經生物降解成壬基苯酚(nonylphenol)，污染水體及其他環境介質，成為受關注的環境荷爾蒙。需要方便及精確的分析方法，以利於該化合物的檢測。 本研究結合固相微萃取(solid-phase microextraction, SPME)及氣相層析質譜儀(gas chromatography-mass spectrometry, GC-MS)發展可應用於檢測水中壬基苯酚的方法。使用50/30 µm Divinylbenzene-Carboxen-Polydimethylsiloxane 的纖維, 以SPME技術頂空萃取水中的壬基苯酚，並搭配GC-MS進行分析。樣品鹽析與酸化後，以田口氏實驗設計觀察濃度、溫度、轉速、平衡時間及萃取時間等變項的影響，進而決定最適萃取條件。 結果顯示，壬基苯酚的吸附量與濃度、溫度、轉速、平衡時間及萃取時間呈現正相關，其中以濃度與溫度影響最為顯著，影響程度分別佔37.52%與24.24%。認為最適萃取條件為溫度75℃、轉速600 rpm、平衡時間5分鐘及萃取時間30分鐘。在此萃取條件下，取實際水樣量測判定方法偵測極限為6.75 µg/L。

Nonylphenol (NP), the product of the non-ionic surfactant nonylpenol ethoxylate (NPEOs) through biodegradation, has been concerned because of its estrogenic properties and widespread contamination in water body and the other environmental media. It is needed to have a simple and accurate method for its determination. This study coupled with solid-phase microextraction (SPME) and gas chromatography-mass spectrometry for analysis of nonylphenol in water. The headspace extraction with 50/30 µm divinylbenzene-carboxen-polydimethylsiloxane fiber of SPME first and followed by analysis of gas chromatography-mass spectrometry was conducted. After salting and pH adjustment, the effects due to the parameters of concentration of nonylphenol, temperature, stirring rate, equilibrium time and extraction time were observed upon the experimental design of Taguchi approach. Thus, the optimum conditions were suggested. The results show that the amount of nonylphenol collected on the selected fiber was correlated with the concentration of nonylphenol, temperature, stirring rate, equilibrium time and extraction time. The two predominant contributors to variation were the concentration of nonylphenol (37.52%) and temperature (24.24%). The proposed optimum conditions were 5 minutes for equilibrium , 30 minutes for extraction at 65℃ and stirring at 600 rpm. Upon this optimum conditions, the method detection limit was 6.75 µg/L when it was applied on a field sample from Danshui River.