次臨界水萃取整治土壤中鄰苯二甲酸酯類之可行性研究

Feasibility Study Using Subcritical Water Extraction for the Remediation of Phthalate Ester-Contaminated Soil

張士強(Matt Shih-Chiang Chang)

指導教授 ： 吳家誠

國立臺灣師範大學/理學院/化學系/碩士(2001年)

摘要

所謂環境荷爾蒙是指可能模仿或阻斷生物體正常的內分泌、增加或減少生物體內荷爾蒙濃度，進而影響了生物體體內正常荷爾蒙的功能的化學物質。常用的塑化劑鄰苯二甲酸酯類( phthalate ester, PAE)，已被日本環境廳與美國環保署列為疑似環境荷爾蒙物質。也因為容易流入環境中，近年來逐漸受到世人的重視。
次臨界水的介電常數可藉由溫度與壓力的控制下來改變，在以液態水的存在下，介電常數會因溫度與壓力的上升而有明顯的下降。本研究以250℃、100 bar (經條件最佳化)的次臨界水來對土壤中的12種PAEs作萃取處理。而處理過後的土壤樣品則利用加速溶劑萃取系統(accelerated solvent extraction, ASE)來做萃取工作，再將其導入HPLC-UV做定性及定量上的分析。此分析方法對土壤中12種PAEs的準確度介於80~125 % 之間，精密度為4.54~9.16 %。方法偵測極限可達0.18(DEHP)~1.70(DEP) μg/g。
在台灣常見三種不同土系的添加分析中，次臨界水對土壤中PAEs的處理效率亦可達80~90 % 以上。顯示對土壤中的PAEs良好的移除率。用以處理土壤之水，經定量分析，發現次臨界水對部分PAEs具有分解作用，其分解機制與條件仍有研究之空間，值得探討。

關鍵字

鄰苯二甲酸酯 ； 加速溶劑萃取 ； 次臨界水 ； 土壤

並列摘要

Environmental Hormones are the compounds that could simulate or disrupt the functions of the hormones. They may increase or decrease the concentraction of the hormones in biological species, and affect their normal physiology. Phthalate esters (PAEs), a popular group of plasticizers, have already been categorized under Environmental Hormones by Environment Agency Government of Japan and United State Environmental Protection Agency. Because they can be easily transfered into our environment and may cause different harmful effects, people began to pay attention to them.
Dielectric constants of subcritical water are easily tunable, since they decrease significantly by raising temperature under moderate pressure, and still keeping water in the liquid state. Subcritical water under the optimized condition of 250℃ and 100 bar are used for the removal of PAEs in soil samples in our study. The subcritical-water-cleaned soil samples are extracted by accelerated solvent extraction system (ASE) and analyzed by HPLC-UV. The accuracy in term of recovery of this method for twelve PAEs in soil was in the range of 80 to 125 % ( RSD< 9.16 % ), and the method detection limits (MDL) ranged from 0.18 (DEHP) to 1.70 (DEP) μg/g.
Three types of soil collected at different sites in Taiwan have been tested. Real samples spiked with different PAEs were treated with subcritical water extraction, and the results indicated a efficiency range of 80~90 % for the removal of PAEs. Results also indicated that certain fractions of PAEs were decomposed under the conditions of subcritical water treatment. Further investigation may be needed to elucidate more information of the results. Our results show that the treatment with subcritical water for PAEs in real soil samples is highly feasible.

並列關鍵字

phthalate ester ； accelerated solvent extraction ； subcritical water ； soil

參考文獻

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