以固相微萃取技術同時檢測水中之三氯乙烷、二氧陸圜及鄰苯二甲酸酯類

Abstract

1,4-二氧陸圜(1,4-dioxane)及鄰苯二甲酸酯類(phthalates)被大量使用在工業上，常見的民生用品也可能含有這些物質，例如：化妝品、清潔劑、食品包裝、醫療用品等，這些物質可能經由人類的使用及排放進入我們的飲水系統。 二氧陸圜及鄰苯二甲酸酯類被認為是新興汙染物質。其中，1,4-二氧陸圜被美國環保署列在第三階汙染物候選名單(CCL3)中，而鄰苯二甲酸酯類中包含磷苯二甲酸二甲酯(Dimethyl phthalate)、鄰苯二甲酸二乙酯(Diethyl phthalate)、鄰苯二甲酸二丁酯(Dibutyl phthalate)、鄰苯二甲酸丁基苯甲酯(Butyl benzyl phthalate)、及鄰苯二甲酸(2-乙基己基)酯[Di(2-ethylhexyl)phthalate]，則被美國潔淨水源法案(U.S. Clean Water Act)提出這些化學物質應該列為優先注意的毒性物質。除此之外，由於二氧陸圜常作為1,1,1-三氯乙烷(1,1,1-trichloroethane)的穩定劑，因此二氧陸圜及三氯乙烷被認為是共同物染物質(co-contaminant)。 為了了解台灣環境水體中這些危害物質的濃度及評估可能的健康風險，本研究利用固相微萃取(Solid-Phase Microextraction)技術，建立同時檢測水中三氯乙烷、二氧陸圜、及鄰苯二甲酸酯類之分析方法。 研究中，先將適用的SPME纖維暴露於含有七種物質已知濃度的水樣中，以直接浸樣的方式進行萃取，針對不同萃取條件進行測試，包含脫附效率、萃取時間、萃取溫度、轉速、鹽析濃度等，以選擇最適萃取條件。萃取完成後，將纖維置於氣相層析儀之注射口進行熱脫附，接著以質譜儀進行定性及定量分析。 本實驗發現，65 μm PDMS-DVB纖維最適合同時採集七種研究目標物質。在選取最適萃取條件後，檢量線建立的線性範圍為0.5~50 μg l-1，且線性良好。七種物質的方法偵測極限(MDL)範圍為0.03~0.3 μg l-1。然而，在方法精確度和回收率的部分，部分物質未達美國環保署建議標準。 本研究嘗試以固相微萃取技術建立了可同時檢測水中三氯乙烷、二氧陸圜、及鄰苯二甲酸酯類之分析方法，欲提供一個快速、簡單、又環保的方式分析這些水中危害物質，而後續研究應針對方法驗證的部分再深入探究。

Among contaminants of emerging concern(CECs), 1,4-dioxane is listed in the third contaminant candidate list(CCL3) of the U.S. EPA, while dimethyl phthalate(DMP), diethyl phthalate(DEP), dibutyl phthalate(DBP), butyl benzyl phthalate(BBP), and di (2-ethyl hexyl) phthalate(DEHP) were mentioned by the U.S. Clean Water Act that they should be considered as priority toxic pollutants. On the other hand, 1,1,1-trichloroethane(TCA) is considered to be co-contaminant of 1,4-dioxane. These seven chemicals are widely used and chances are they may enter the drinking water system. To assess the possible health risk, method of determining 1,1,1-trichloroethane, 1,4-dioxane, and phthalates in water simultaneously was developed in this research. Including dimethyl phthalate(DMP), diethyl phthalate(DEP), dibutyl phthalate(DBP), butyl benzyl phthalate(BBP), di (2-ethyl hexyl) phthalate(DEHP), 1,1,1-trichloroethane(TCA), and 1,4-dioxane were prepared in mixtures as the standard solutions. The samples were first equilibrated for 1 minute before the extraction. Hence, the 65 μm PDMS-DVB solid phase microextraction (SPME) fiber was used for direct sample immersion at 30°C for 30 minutes with 250 rpm. Afterwards, the SPME fiber was inserted into the injection port of the gas chromatography-mass spectrometry(GC-MS) for thermal desorption and further analysis. The SPME procedure coupled with GC/MS analysis for the determinations of 1,1,1-trichloroethane, 1,4-dioxane and phthalates in water sample simultaneously was established in this study. No carry-over effect was observed. The linear range of all compounds ranged from 0.5 to 50 μg l-1. Good linearity was presented. However, the precision and accuracy of target compounds in this study did not perform very well. The SPME procedure was applied in this study, while advantages over conventional methods, such as solve-free and time-saving, were reached. Besides, the sensitivities of the method for different compounds were low enough to determine the concentrations from environmental water samples. Further tests are needed to get better precision and accuracy.