title: Supercritical fluid extraction of chemical warfare agent simulants from soil.
abstract: Chemical warfare agent simulants are efficiently recovered from 2-ppm spikes in 1 g of Rocky Mountain Arsenal Standard Soil using methanol-carbon dioxide (5:95) at 300 atm for 2 min at 60 degrees C. Recoveries (n = 3) were 79 +/- 23% for dimethylmethylphosphonate, 93 +/- 14% for 2-chloroethylethyl sulfide, 92 +/- 13% for diisopropylfluorophosphate and 95 +/- 17% for diisopropylmethylphosphonate. Recoveries are higher than, but less precise than those achieved from a 5-min ultrasonic micro-scale extraction using methanol. Much less laboratory waste is generated than the current standard organic solvent extraction method (33 g of soil shaken with 100 ml of chloroform).
authors.affiliation: Analytical Chemistry Division, Oak Ridge National Laboratory, TN 37831-6120.
authors.forename: W H
authors.initials: WH
authors.lastname: Griest
authors.forename: R S
authors.initials: RS
authors.lastname: Ramsey
authors.forename: C H
authors.initials: CH
authors.lastname: Ho
authors.forename: W M
authors.initials: WM
authors.lastname: Caldwell
mesh_terms: D002619:Chemical Warfare Agents / Q000302:isolation & purification*; D002849:Chromatography, Gas; D002853:Chromatography, Liquid / Q000379:methods; D005410:Flame Ionization; D007531:Isoflurophate / Q000302:isolation & purification; D009151:Mustard Gas / Q000031:analogs & derivatives / Q000302:isolation & purification; D009943:Organophosphorus Compounds / Q000302:isolation & purification; D012989:Soil Pollutants / Q000302:isolation & purification*
chemical_list: D002619:Chemical Warfare Agents; D009943:Organophosphorus Compounds; D012989:Soil Pollutants; D007531:Isoflurophate; C031116:dimethyl methylphosphonate; C023477:diisopropyl methylphosphonate; C031278:2-chloroethyl ethyl sulfide; D009151:Mustard Gas