title: Development of supercritical carbon dioxide extraction with a solid phase trap for dioxins in soils and sediments.
abstract: A method involving supercritical fluid extraction (SFE) with a solid phase trap containing activated alumina was investigated for the rapid analysis of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin like polychlorinated biphenyls (DL-PCBs) in soils and sediments. The samples were extracted by using supercritical carbon dioxide with water (2% versus CO(2) flow velocity) being used as an entrainer at a pressure of 30 MPa and a temperature of 130 degrees C for 50 min. The extracts were adsorbed on an activated alumina trap that was maintained at a temperature of 150 degrees C, and then, PCDD/DFs and DL-PCBs were eluted with 20 ml of hexane at 60 degrees C. After concentration, they were measured with a high-resolution gas chromatograph interfaced to a high-resolution mass spectrometric detector. The average concentrations of PCDD/DFs and DL-PCBs corresponded to the results obtained by the conventional method, and the reproducibility of this SFE method was below 21% of the relative standard deviations for all samples. The total time required for the analysis of the pretreatment of this method was only 2 h.
authors.affiliation: Department of Environmental Science for Industry, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan. miyawaki@agr.ehime-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyawaki
authors.forename: Ayato
authors.initials: A
authors.lastname: Kawashima
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Honda
mesh_terms: D001572:Benzofurans / Q000737:chemistry / Q000302:isolation & purification; D002245:Carbon Dioxide / Q000737:chemistry*; D025924:Chromatography, Supercritical Fluid / Q000295:instrumentation / Q000379:methods*; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins / Q000737:chemistry* / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry; D019015:Geologic Sediments / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification; D015203:Reproducibility of Results; D012989:Soil Pollutants / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants; D002245:Carbon Dioxide