| 摘要: | 揮發性脂肪酸是有機物質進行厭氧性分解中最常見的中間產物。本研究採用頂空固相微萃取具有簡便、快速、不需使用有機溶劑及不受基質干擾之優點，結合氣相層析儀，測定垃圾污水中揮發性脂肪酸之含量分析。研究中使用75 μm Polydimethylsiloxane/Carboxen（PDMS/CAR）纖維，針對纖維吸附時間、吸附溫度、脫附時間、脫附溫度等因素分別探討，結果顯示在1200 rpm攪拌速率下，於室溫中吸附20分鐘後，將吸附纖維直接插入氣相層析儀，利用儀器注射口之250℃設定溫度，進行3分鐘熱脫附後，再以GC-FID進行分析，是為實驗最佳萃取分析條件。 測試酸標準溶液之檢量線及方法偵測極限，在乙酸、丙酸、丁酸、異丁酸標準品檢量線之相關係數（r值）均大於0.995以上，而方法偵測極限的結果，乙酸為9.2μg/ml、丙酸2.65μg/ml、丁酸3.11μg/ml、異丁酸2.47μg/ml，偵測極限均可達到ppm結果；其精密度在10﹪以下，準確度之範圍為88.04-112.32﹪. 固相微萃取之設備簡單，操作容易，非常適合於野外之環境樣品採樣，本研究選擇垃圾污水做為實際樣品，此法可以簡化採樣及樣品前處理之繁瑣過程，並能減低經濟分析成本，是為一項實務上應用相當有效率的樣品前處理方法。; Volatile fatty acids（VFA） are the most common intermediate products generated from anaerobic decomposition of organic substances. This study develops a headspace solid phase microextraction procedure for sampling of VFA. This method is simple, convenient, and fast. It does not require organic solvents, and is not interfered by base materials. It combines the gas chromatograph to determine the analysis of volatile fatty acids contents in the trash wastewater. In this study, 75 μm PDMS/CAR fiber was used. The fiber absorption time, absorption temperature, desorption time and desorption temperature were studied to determine the optimal extraction analysis conditions. The results showed that the best absorb time was 20 minutes at 1200 rpm mixing speed under room temperature. The injection point temperature of the instrument was set at 250℃, with 3 minutes of hot desorption. GC-FID was used for analysis. The linear correlation coefficient of standards acetic acid, propanoic acid, butyric acid, and iso-butyric acid are all greater than 0.995. The detection limits for acetic acid, propanoic acid, butyric acid, and iso-butyric acid were 9.2 μg/ml, 2.65μg/ml, 3.11μg/ml, 2.47μg/ml, respectively. The detection limits were all within ppm range. The precision were lower than 10﹪. The accuracy were in the range of 88.04-112.32﹪. The equipment for solid phase microextraction is simple, easy to operate and is very suitable for field environment sampling. This research selects trash wastewater as real sample to test applicability of this microextraction method. This method may simplify the complex procedure of sampling and sample pre-processing, and lower analysis costs. It is a very practical and effective pretreatment method. |
