直鏈式烷基三甲基銨鹽類(Alkyltrimethyl ammonium chloride，ATMACs)為主要陽離子型界面活性劑之一，此類陽離子型界面活性劑與帶負電荷的物質表面易形成親和作用，並有殺菌效果，而適用於工業及民生用品中。但因其在缺氧環境中，物、化性及本身不易被生物分解的特質，能穩定存在於厭氧性污泥與水環境中，毒性能藉由環境中滲入到細胞粒腺體膜中，破壞生物體生物能量ATP之生產機制，促使細胞死亡，而在臺灣的年生產與使用量大約8000噸，且近年有逐年增加的趨勢，因此對於環境的污染不容小覷。此類界面活性劑主要用作潤髮乳與衣物柔軟精中，其同系物有C12-，C14-，C16-，C18-TMACs，因此針對此污染物有必要發展一套快速、穩定的分析檢測方法，來探討ATMACs在水環境中的來源與宿命。 本研究主要是以氣相層析儀之大體積進樣裝置行高溫熱裂解反應，並以離子阱質譜儀檢測欲分析之待測物，達到定性與定量之分析目的。並藉著添加過量之碘化鉀(KI)使之與水樣中之ATMACs形成離子配對，進而利用液-液相萃取方法，萃取出待測物，而在500 ml東港溪水樣中ATMACs之平均回收率分別為71％，77％，94％，72％，相對標準偏差(RSD)分別為13%、19%、16%、15%，且台灣各河水中偵測ATMACs的含量約為0.02~0.66μg/L。而日常用品中之潤髮乳與衣物柔軟精中之ATMACs以C16，C18為主，其百分比含量分別為0.19%~2.72%與0.06~5%。 This study presents a modified method to analyze alkyltrimethyl ammonium chlorides (ATMACs) in conditioners and river water. The conditioner samples were directly diluted by methanol. The procedure for water sample (adjust pH to above 10) involved mixed sample with potassium iodide (KI) as a counter-ion to enhance the extraction of ATMAC residues by dichloromethane liquid-liquid extraction. The ATMACs were then demethylation to their corresponding nonionic alkyldimethyl amines by thermal decomposition in the injection port. The corresponding alkyldimethylamines were then identified and quantitated by gas chromatograph-mass spectrometry (GC-MS) with electron impact (EI) and chemical ionization (CI) modes. The results indicate that relatively high amount of alkyldimethylamine were detected at the demethylation temperature higher than 290°C in the injection port. The method proposed herein provides a high precision and sensitivity for ATMACs, to quantitation at < 0.01 mg/L in 500 ml of the water samples. Recovery of the ATMACs in spiked various water samples ranged from 71% to 94% while RSD ranged from 7 to 21%. Concentrations of ATMACs in conditioners varied from 0.2 to 5.0%, while C16-TMAC and C18-TMAC were two major homologs. Concentrations in river waters varied from 0.02 to 0.66 mg/L. Indirect HPLC method was applied to evaluate the GC-MS method, and the compatible results were obtained.
