title: Dioctyl sulfosuccinate analysis in near-shore Gulf of Mexico water by direct-injection liquid chromatography-tandem mass spectrometry.
abstract: Dioctyl sulfosuccinate (DOSS) was a major component of the dispersants most used in the 2010 Deepwater Horizon Oil Spill incident response. This analytical method quantifies salt water DOSS concentrations to a reporting limit of 20 μg/L, which was below the United States Environmental Protection Agency's (U.S. EPA) 40 μg/L DOSS Aquatic Life Benchmark. DOSS in Gulf of Mexico water samples were analyzed by direct-injection reversed-phase liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample preparation with 50% acetonitrile (ACN) enabled quantitative transfer of DOSS and increased DOSS response 20-fold by reducing aggregation. This increased sensitivity enabled the detection of a confirmatory transition over the calibration range of 10-200 μg/L. U.S. EPA Region 5 and Region 6 laboratories analyzed hundreds of near-shore surface Gulf of Mexico water samples, none contained more than the 20 ppb reporting limit. The matrix spike DOSS/deuterated surrogate (DOSS-D34) correlation of determination varied with mobile phase modifier (ammonium formate R(2)=0.95 and formic acid R(2)=0.27). Using ammonium formate, DOSS-D34 accurately measured DOSS matrix effect. The near-shore sodium concentrations varied more than 10,000-fold, but were not strongly correlated with DOSS recovery. DOSS detection by LC-MS/MS enabled rapid analysis which was valuable in guiding incident response.
authors.affiliation: United States Environmental Protection Agency, Houston Regional Laboratory, 10625 Fallstone Road, 6MD, Houston, TX 77099, USA.
authors.forename: Johnson
authors.initials: J
authors.lastname: Mathew
authors.forename: David L
authors.initials: DL
authors.lastname: Schroeder
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Zintek
authors.forename: Caitlin R
authors.initials: CR
authors.lastname: Schupp
authors.forename: Michael G
authors.initials: MG
authors.lastname: Kosempa
authors.forename: Adam M
authors.initials: AM
authors.lastname: Zachary
authors.forename: George C
authors.initials: GC
authors.lastname: Schupp
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Wesolowski
mesh_terms: D002138:Calibration; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D004143:Dioctyl Sulfosuccinic Acid / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D060851:Gulf of America; D009792:Oceans and Seas; D059392:Petroleum Pollution / Q000032:analysis*; D012680:Sensitivity and Specificity; D013501:Surface-Active Agents / Q000032:analysis; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D004143:Dioctyl Sulfosuccinic Acid