| dc.description.abstract | 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. | en_US |