| 摘要: | 多氯萘(Polychlorinated naphthalenes, PCNs)於20世紀初開始生產並大量使用於各種工業，例如染料製造，木材，紡織和造紙工業；作物殺菌劑，增塑劑，油品添加劑，以及用於鑄造合金材料及石墨電極的潤滑劑。因其對環境的危害， 20世紀末各國已終止多氯萘的生產。但這些化合物仍可經不同的形式釋放至環境，例如：過去使用的多氯萘及含多氯聯苯的商業產品（多氯萘為多氯聯苯製造過程產生的副產品），廢棄物焚化和其他熱處理過程。此外，國內也曝露在多氯萘的高風險中，國內有許多，多氯萘潛在的排放源，如工業生產過程和焚化爐的排放，因此調查多氯萘為當務之急。本研究建立量測環境樣品中多氯萘濃度的檢測方法並據以分析水庫與河川底泥中多氯萘的濃度及物種分布特性，以供未來相關檢測與研究之用。本研究參考國外經驗之前處理程序，萃取部分則綜合過去多篇文獻，列出四種常使用之萃取溶劑，如:二氯甲烷、甲苯、二氯甲烷與正己烷混合溶劑(體積1:1)、丙酮與正己烷混合溶劑(體積1:1)，分別萃取底泥24小時，結果說明以二氯甲烷萃取底泥樣品，其內標準品之回收率範圍介於41~89%。淨化部分以不同體積之沖洗液沖洗，5毫升甲苯、10毫升甲苯、15毫升甲苯沖洗液，並探討其對多氯萘內標準品之回收率，結果顯示5毫升甲苯沖洗，對多氯萘回收率最差。5毫升甲苯無法有效將多氯萘物種全部分離，15毫升甲苯因沖洗體積較多減壓濃縮較久，導致一、二氯萘揮發，使其回收率降低。因此10毫升甲苯為最適合淨化沖洗液體積，結合上述之最佳萃取溶劑二氯甲烷及最適合淨化沖洗液體積10毫升甲苯，為最適合多氯萘前處理程序。品管與品保部分，七個空白基質添加樣品平均內標準品回收率為29-106%，待測物回收率63-98%，底泥真實樣品回收率則為48-111%。方法偵測極限(MDL)介於0.28-1.86 pg/g。水庫與河川底泥濃度分別為35.6-80.9 pg/g-dw及1.48-6.40 ng/g-dw，皆以下游濃度最高，但河川底泥之多氯萘濃度明顯高於水庫底泥；物種分布水庫底泥以四氯萘為優勢物種，河川底泥則以五氯萘為主。;Production of polychlorinated naphthalenes (PCNs) can be traced back to the beginning of 20th century and they are widely used for various industries such as dye manufacturing, wood, textile and paper industries, crop pesticides, plasticizers, oil additives, alloy casting and lubricant of graphite electrode. PCNs production has been prohibited in the end of 20th century due to the hazard to environment. However, PCNs are still emitted into environment via several ways including consumed PCNs and polychlorinated biphenyls (PCBs)-containing commercial products (PCNs are byproducts formed from PCBs manufacturing), waste incineration and thermal processes. There are lots of potential emission sources of PCNs in Taiwan, for instance, industrial production and waste incineration. Hence, assessment of PCNs emission and distribution in environment is of urgency. In this study analysis method is developed and applied for the measurement of PCNs concentration/distribution in sediment collected from reservoir and river. Pretreatment methods are developed based on the studies conducted in other international laboratories. For extraction methods, we consulted much literature and applied four common extraction solutions, including dichloromethane, toluene, dichloromethane/n-hexane mixture (v/v = 1/1) and acetone/n-hexane mixture (v/v = 1/1) to extract sediment for 24 hours. Results indicate dichloromethane has the best internal standard recovery rate, which is between 41 ~ 89%. For purification, 5, 10 and 15 mL of toluene are used individually to investigate the effects on PCNs internal standard recovery rate. Results show that 5 mL of toluene has lower PCN sample recovery rates because 5 mL of toluene is insufficient to wash out all of PCN species while 15 mL of toluene need to be concentrated under reduced pressure for longer time, leading to the reduction of recovery rate, and 10 mL of toluene is the best. Hence, combining the best extraction solvent and the best purification collection volume forms the most appropriate pretreatment process. For quality control and quality assurance, 7 blank matrix-spiked samples have the average internal standard recovery rate of 29-106% for mono- to octachlorinated PCNs, analyte recovery rate of 63-98% and sample recovery rate of 48-111% are obtained. Furthermore, the method detection limits range from 0.28 to 1.86 pg/g, and the PCN concentrations in reservoir and river range from 35.6 to 80.9 pg/g-dw and 1.46-6.40 ng/g-dw, respectively. The highest PCN concentration is measured in the downstream. Tetrachlorinated PCNs and pentachlorinated PCNs are dominating species. |
