| 英文摘要 |
The project for developing the method for the analysis of polychlorinated naphthalene (PCNs) in fly ash has been completed. The tests of pretreatments and instrument parameters have been carried out. The pretreatment tests were devided into extraction and clean-up process. The results of clean-up tests indicate that the effects of adsorbents on PCNs separation are significant and depend on the adsorption capability of adsorbent. Non-polar adsorbent such as activated carbon with a high specific area has the advantage of high adsorption capacity and can separate high boiling point interferences from analyzte, however, it has the disadvantages of being costly and time-comsuming. Additionally, in the test of the polar adsorbents, Aluminum exhibits a higher adsorption ability than Florisil. For the extraction test, dichloromethane (DCM), hexane/acetone (1:1, v/v) and toluene have been selected as solvents. The results show that DCM has a high extraction efficiency for Mono-CN to Tri-CN while higher extraction efficeiencies can be achieved for Tetra-CN to Octa-CN as toluene is applied as solvent. Besides, toluene also can effectively extract aromatic compounds from the high-carbon matrix such as flyash and sediment. Thus, toluene is selected to extract samples in this study. The Quality Assurance and Quality Control (QAQC) have also been conducted. The method detection limit has been evaluated repeatedly with 0.1 ng/mL PCN following the methods of NIEA-PA107. Furthermore, the results of the precision test indicate that the recovery efficiencies PCNs analyte and internal standard are within the range of 99.4%-106% and 51%-90.7%, respectively. The control standards of PCN recovery efficiency for NIEA are suggested according to the results. Comparison of PCNs analysis between High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS) with 60 m column and Gas Chromatography/Tandem Mass Spectrometry (GC-MS/MS with 40 m) column has been made. The results point out that the properties of column are the critical to affect the separation efficiency of PCNs compounds. From Mono-CN to Tri-CN pattens, MonoCNs and DiCNs exhibit higher resolution with HRMS than that with GC/MSMS. However, low resolution results may cause uncertainty of quantification. Besides, higher peak of RS (13C-tetra-PCB) is attributed to low recovery efficiencies of Mono-CN to Tetra-CN as GC/MSMS is applied for the analysis.
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