title: Selective extraction of hydrocarbons, phosphonates and phosphonic acids from soils by successive supercritical fluid and pressurized liquid extractions.
abstract: Hydrocarbons, dialkyl alkylphosphonates and alkyl alkylphosphonic acids are selectively extracted from spiked soils by successive implementation of supercritical carbon dioxide, supercritical methanol-modified carbon dioxide and pressurized water. More than 95% of hydrocarbons are extracted during the first step (pure supercritical carbon dioxide extraction) whereas no organophosphorus compound is evidenced in this first extract. A quantitative extraction of phosphonates is achieved during the second step (methanol-modified supercritical carbon dioxide extraction). Polar phosphonic acids are extracted during a third step (pressurized water extraction) and analyzed by gas chromatography under methylated derivatives (diazomethane derivatization). Global recoveries for these compounds are close to 80%, a loss of about 20% occurring during the derivatization process (co-evaporation with solvent). The developed selective extraction method was successfully applied to a soil sample during an international collaborative exercise.
authors.affiliation: Direction des Centres d'Expertise et d'Essais, ETC-4, Centre d'Etudes du Bouchet, Vert-le Petit, France.
authors.forename: X
authors.initials: X
authors.lastname: Chaudot
authors.forename: A
authors.initials: A
authors.lastname: Tambuté
authors.forename: M
authors.initials: M
authors.lastname: Caude
mesh_terms: D002845:Chromatography / Q000379:methods*; D006838:Hydrocarbons / Q000302:isolation & purification*; D063065:Organophosphonates / Q000302:isolation & purification*; D011312:Pressure; D012987:Soil / Q000032:analysis*
chemical_list: D006838:Hydrocarbons; D063065:Organophosphonates; D012987:Soil