| "The Law Concerning Special Measures Against Dioxins (Law No. 105 of 1999) requires river and harbor managers to take countermeasures of the sediment polluted by dioxins (DXNs) exceeding the environmental standard (150pg-TEQ/g). To this end large number of samples would be required to be analyzed to determine the polluted area to be improved, but the analytical method designated by the law is time-consuming and expensive. Therefore this study focuses on the applicability of inexpensive and rapid analytical methods for dioxins (DXNs) in river sediments. We set 30 combinations of detection methods including enzyme-linked immunosorbent assay, semi-non-volatile organic halogen method and GC-MS(Q-pole) method focusing on a selected isomer of DXNs, and pretreatment methods including soxhlet extraction method, pressurized fluid extraction method (PFE), high speed solvent extraction method and several clean-up methods. The results examined by the combinations were compared with those designated by the law based on 20 samples that were obtained from possible DXNs contaminated sites in four rivers. Judging from the correlation factors, GC-MS (Q-pole) method focusing on 2,3,7,8-TCDD showed the highest values with any pretreatment methods among the selected detection methods. Particularly, the GC-MS (Q-pole) method following PFE, multi-silica layer gel column chromatography and activated carbon column chromatography was largest in correlation factor." |
