| 摘要: | 六溴環十二烷(Hexabromocyclododecane, HBCD)是目前工業上最常用的添加型耐燃劑之一。六溴環十二烷具有價格便宜，效果良好以及使用方便的特色，因此被廣泛的添加於電子產品及紡織品的塑膠中，作為防火耐燃劑。過去的研究顯示，因為有明顯的生物累積效應，它的濃度在食物鏈越末端會越高。過去的毒性研究則顯示六溴環十二烷具有干擾生物體內分泌的特性，以及可能為人體致癌物。由於過去台灣還沒有針對環境中六溴環十二烷相關研究，因此，有必要發展一套監測環境中六溴環十二烷濃度的方法。我們的實驗目的即是開發一套檢測固態樣品中，六溴環十二烷含量的檢測方法。 在實驗的第一部份，我們成功的分離了三種立體異構物，並且確定了三種異構物的滯留時間，層析峰的半高寬約在0.2到0.3分鐘之間。第二部分我們比較了大氣壓力光游離介面(Atmospheric Pressure Photo Ionization, APPI)與電灑游離介面(Electrospray Ionization, ESI)，發現兩種游離介面都可以用來進行六溴環十二烷的游離工作。大氣壓力光游離介面有較好的線性範圍以及較不容易受到基質干擾，但是即使以加入正辛烷作為摻雜劑的方式提昇大氣壓力光游離介面的訊號強度，電灑游離介面依然有遠低於大氣壓力光游離介面的偵測極限 (limit of detection, LOD)。接下來我們比較了加壓溶液萃取法(pressure liquid extraction, PLE)與索氏萃取法(soxhlet extraction, SE)的萃取效果，在最佳化的萃取條件下，對三種立體異構物加壓溶液萃取的回收率均高於58 %，相對標準偏差值(RSD)介於1.9%-5.6%之間。對三種立體異構物索氏萃取的回收率均高於 61.8%，相對標準偏差值(RSD)介於2.7%-14.9%之間。兩種萃取方法均能有效的萃取樣品中的六溴環十二烷，但由於加壓溶液萃取較節省溶劑以及萃取時間，因此為較好的萃取方法。我們也單獨測定了淨化步驟的回收率，對於三種立體異構物淨化步驟的回收率均大於86%，相對標準偏差值(RSD)介於2.7%-6.3%.之間，顯示淨化步驟對回收率的損失只有很小的影響。最後，我們將標準品加入真實樣品中，可以得到可接受的回收率，證明我們的方法的確適用於樣品中六溴環十二烷的檢測。然而在已測試的底泥樣品中，我們還沒有測到六溴環十二烷的存在。 HBCD is one of the important class of additive flame retardants in commerce. Because it is a cheap, reliable compoundd and is easy to be used by adding directly, HBCD is widely used in the plastic of electric products and textile industries as a flame retardant. Because of it’s lipophilic property and structure stability, it behaves remarkable bioaccumulation. Previous studies have shown that concentrations of HBCD are rising alone the food chain. Some toxic researchs heve shown that it has the risk to effect endocrine system of animal or it may be as a carcinogen. Consequently, it is necessary to develop analytical methods for routinely determining the levels of HBCD in Taiwan. The purpose of this study is to develop a reliable method for routinely determining the levels of hexabromocyclododecane (HBCD) in solid samples. In the first part of our study, we separated the three disastereomers and identify each of their retention time. The width of the half peak high is about 0.2-0.3 minutes. In the second part, we compared the ionization ability of Atmospheric Pressure Photo Ionization (APPI) and Electrospray Ionization (ESI) for HBCD. The results show that the two ion sources are both practicable for the ionization of HBCD. APPI shows a better linear dynamic range and less influences from matrix effect. However, ESI shows a much lower limit of detection (LOD). In the third part, we compared two extraction methods of soxhlet extraction (SE) and pressure liquid extraction (PLE). In optimized conditions, the recovery of PLE is more than 58%, RSD is between 1.9%-5.6%. The recovery of SE is more than 61.8%, RSD is between 2.7%-14.9%. Both of them are practicable in HBCD analysis. We also test the recovery of the clean up step. The recovery of acidic silica column is more than 86%, RSD is between 2.7%-6.3%. It means that the clean up step will not reduce the recovery of extraction dramatically. At last we proved that our method is practicable by spiking standard to sediment to get an acceptable recovery. But we still did not detect any hexabromocyclododecane in sediment samples yet. |
