比較垂直震盪器輔助乳化微萃取法與低濃度界面活性劑為分散劑液液微萃取法偵測水樣中雙苯醚類除草劑之效果

除草劑為人類的生活提供一定的便利性，然而隨著雨水沖刷與河川的流動，這些化學物質不經意地就進入環境當中。本篇測定的雙苯醚類除草劑被懷疑具有致癌性，因此能否檢測其含量是個重要議題。本研究主要是比較以垂直震盪器輔助乳化與低濃度界面活性劑當分散劑進行液液微萃取法兩者的差異。前者是利用垂直震盪器促使萃取溶劑分散在水中，並搭配快速搖盪增加萃取溶劑與水樣之間的物質交換 (mass transfer)；後者則是以界面活性劑使萃取溶劑分散成小液滴後打入樣品內，因為呈現小液滴狀態可增加萃取溶劑與樣品的接觸面積，故可在極短時間內完成萃取。經由最佳化過後，垂直震盪器輔助乳化的萃取溶劑是30 μL乙酸癸酯、添加氯化鈉0.25克、震盪時間3分鐘，以5000 rpm轉速離心5分鐘後可在上層獲得萃取液滴，將其取出後以10 μL打入高效能液相層析儀進行分析。此方法的線性濃度在2-1000 μg L-1之間，決定係數 (r2)皆在0.9992以上，偵測極限0.62-1.74 μg L-1之間，低於臺灣放流水標準 (1 mg L-1)。界面活性劑為分散劑的方法，最佳化結果是以33 μL的乙酸癸酯為萃取溶劑，濃度1 mg L-1的tween 60為界面活性劑，使用體積150 μL，在不加氯化鈉的情況下進行萃取。此方法的線性濃度在2-1000 μg L-1之間，決定係數 (r2)皆在0.9988以上，偵測極限0.72-1.38 μg L-1之間，亦低於臺灣放流水標準。

關鍵字

垂直震盪器；界面活性劑；雙苯醚類除草劑；微萃取；高效能液相層析儀

並列摘要

In this study, we compare two methods which are used to detect five diphenylether herbicides. One is up-and-down shaker-assisted emulsion, the other is water with low concentration of surfactant in dispersed solvent-assisted emulsion dispersive liquid–liquid microextraction (WLSEME). The first method cause the extraction solvent to form fine droplets in the sample solution by shaking violently. After optimization, this method can finish extraction in three minutes using only 30 μL of decyl acetate. The linear range is 2-1000 μg L-1 and r2 is greater than 0.9992; detection limit is from 0.62 to 1.74 μg L-1. The relative recoveries range from 90 to 102% for river water; 88–104% for lake water and 93–102% for irrigating water. The WLSEME method use a microsyringe to withdrew and discharge extraction solvent and 1 mg L-1 tween 60 (as the dispersed solvent) four times within 10 seconds. After that, a cloudy emulsified solution is formed in the syringe. The effect of various experimental parameters on extraction conditions were studied. The linear range is from 2 to 1000 μg L-1 for the target compounds, and the LODs are between 0.72 and 1.38 μg L-1. The relative recoveries range from 95 to 108% for river water; 96–109% for lake water and 86–114% for irrigating water.

並列關鍵字

UDSA-DLLME ； WLSEME ； diphenylether herbicides ； microextraction ； HPLC

參考文獻

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國際替代計量

比較垂直震盪器輔助乳化微萃取法與低濃度界面活性劑為分散劑液液微萃取法偵測水樣中雙苯醚類除草劑之效果

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