Simultaneous extraction and determination of anionic surfactants in waters and sediments.
A new method has been developed for the simultaneous determination of the most frequently used anionic surfactants - linear alkylbenzene sulfonates (LAS), alkyl ethoxysulfates (AES) and alkyl sulfates (AS) - in aqueous and sediment samples. Preconcentration and purification of water samples are carried out by means of solid-phase extraction (SPE). The efficiency of two different extraction methods for the analysis of sediments - Soxhlet extraction and pressurized liquid extraction (PLE) - has been compared. Identification and quantification of the target compounds is performed using a liquid chromatography - mass spectrometry (LC-MS) system equipped with an electrospray interface (ESI) in negative ion-mode. Homologue recoveries are 85-123% for SPE, 94-112% for Soxhlet extraction and 81-125% for PLE in the case of LAS, and 60-94% for SPE, 61-109% for Soxhlet extraction and 55-99% for PLE in the case of AES, whereas the limits of detection are 0.1-0.5 ngml(-1) in water and 1-5 ngg(-1) in sediment. This method has been applied to the determination of anionic surfactants in the Guadalete estuary (SW Spain), and LAS concentration levels from 538 to 1014 ngg(-1) in sediments and from 25.1 to 64.4 ngml(-1) in waters have been found. AES values from 168 to 536 ngg(-1) in sediments and from 4.5 to 11.9 ngml(-1) in waters are reported for the first time in European rivers.
Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Campus Río San Pedro s/n 11510 Puerto Real, Cádiz, Spain.
Pablo A
PA
Lara-Martín
Abelardo
A
Gómez-Parra
Eduardo
E
González-Mazo
D017738:Alkanesulfonic Acids / Q000032:analysis / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D012623:Seawater / Q000737:chemistry; D013463:Sulfuric Acid Esters / Q000032:analysis; D013501:Surface-Active Agents / Q000032:analysis* / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D017738:Alkanesulfonic Acids; D013463:Sulfuric Acid Esters; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical