以固相微萃取技術搭配動態非平衡暴露系統進行泳池空氣中消毒副產物採樣之方法開發

Abstract

游泳池是許多人會去運動和休閒的地方，但是在經過加氯消毒之後，水中餘氯會和人體帶進去的含氮物質結合生成消毒副產物。由於文獻指出，長期在室內泳池中活動的人容易罹患上呼吸道疾病，空氣中的消毒副產物的暴露評估因此也變得重要。 根據文獻資料和物質特性，本研究選定泳池空氣中較常見的三鹵甲烷(氯仿、二氯一溴甲烷、一氯二溴甲烷、溴仿)以及三氯胺作為目標化學物質，而由於目前的測定方法較為繁瑣，兩類物質無法同時測定，必須使用不同的採樣器並搭配不同的採樣方法與分析儀器，樣品前處理過程也相當繁瑣，因此本研究的目的為開發以固相微萃取搭配動態系統的快速空氣採樣與分析方法，目前並無任何其他研究使用固相微萃取與質譜儀來分析空氣中之三氯胺，而藉由固相微萃取的優點和特性，空氣中之三鹵甲烷也可以一同採集，以一個簡單的方法省去繁瑣的樣品前處理步驟來同時測定泳池空氣中之三鹵甲烷與三氯胺，將是本研究之最大突破。 本研究經配置好一定濃度之三鹵甲烷與三氯胺溶液後，利用注射幫浦分別將兩類物質帶入動態系統分流並以高溫汽化，三氯胺的路線途中則以純水與氨基磺酸進一步純化，在進入暴露腔前將兩類物質匯流，以固相微萃取之纖維在暴露腔內進行採樣，暴露過程三鹵甲烷的濃度固定為0.01mg/m3，三氯胺的濃度固定為5mg/m3，並以23、30、37、45、52與60分鐘分別進行暴露測試。 。本研究藉由暴露時間的不同變化獲得每個物質之實驗採樣率；方法開發完成後，則進一步到泳池中進行實地採樣並與傳統方法進行平行比對，藉以驗證本研究所建立方法之可信度，該泳池為一室內游泳池，採樣地點選在泳池某測的地板上，按照各方法的要求與條件進行90分鐘之採樣。。 利用本研究所建立的動態採樣系統，發現氯仿的實驗採樣率為9.17×10-1 cm3/sec；二氯一溴甲烷為1.31 cm3/sec；一氯二溴甲烷為1.58 cm3/sec；溴仿為1.35 cm3/sec；三氯胺為9.4×10-1 cm3/sec。實地採樣結果顯示傳統方法無法測得泳池空氣中之dichlorobromomethane、dibromochloromethane以及bromoform，但相較之下，本研究所開發之方法可以偵測到dichlorobromomethane及dibromochloromethane，顯示出本研究的敏感度高於傳統方法。將泳池採樣結果與實驗室內模擬結果平行比對兩類方法，chloroform所得到的數值進行迴歸分析，可得到係數為0.91，R2為0.95之關係。另一方面，於三氯胺的部分，本研究所開發之方法和傳統方法可以得到係數為0.93，R2為0.90的迴歸線，顯示出本研究所開發方法和舊的傳統方法所測得的環境濃度有相當程度的一致性。 本研究所開發之方法可同時測量空氣中之三鹵甲烷與三氯胺，相較於傳統方法也有較高的敏感度，也簡化了檢測的繁瑣流程，提供更好的方法來測量泳池空氣中之消毒副產物。

Swimming pool is a popular place for many people. During the process of disinfection for pool water, chlorine will react with nitrogenous compound and organic matter brought by human to form by-products. Many studies point out the attendance of indoor swimming pool has relation with the occurrence of upper respiratory symptom. Hence, the airborne disinfection by-products (DBPs) in the indoor swimming pool cause concerns. Considering the occurrences and characteristics, the DBPs including trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, bromoform) and trichloramine were the compounds of interests for current research. In addition, there is a need to assess the associated airborne concentrations. However, the traditional procedures to determine these DBPs in air were complicated. In addition, no study has been using solid-phase microextraction (SPME) with gas chromatography/mass spectrometer (GC/MS) to determine NCl3 and THMs simultaneously. Hence, this study aimed to develop a sampling and analysis method by using SPME with dynamic exposure system. For method validation, standard solutions of trichloramine and trihalomethanes were first prepared, and were injected into the dynamic generation system for vaporization and exposure afterwards. Besides, field validation at an indoor swimming pool was performed by sampling NCl3 and THMs side-by-side with SPME method as well as traditional methods. It was found that the experimental sampling rates for chloroform, bromodichloromethane, dibromochloromethane, bromoform and trichloramine were 9.17×10-1 cm3/sec, 1.31 cm3/sec, 1.58 cm3/sec, 1.35 cm3/sec and 9.4×10-1 cm3/sec, respectively. The results from field sampling were consistent between traditional method and SPME method for THMs (the coefficient was 0.91 and R2 was 0.948), while the latter provided better sensitivity. In the part of trichloramine, the regression of two method showed the coefficient was 0.93 and R2 was 0.9. These result showed that the method we developed had similar result to traditional methods and can be reliable. The method developed in this study can be used to determine the airborne THMs and NCl3 simultaneously. Compare with traditional methods, the SPME technique has simplified the procedure with higher sensitivity. It can provide a better tool to assess the air quality in indoor swimming pools.