title: Determination of sedative hypnotics in sewage sludge by pressurized liquid extraction with high-performance liquid chromatography and tandem mass spectrometry.
abstract: This paper describes a method for the determination of eight sedative hypnotics (benzodiazepines and barbiturates) in sewage sludge using pressurized liquid extraction and liquid chromatography with tandem mass spectrometry. Pressurized liquid extraction operating conditions were optimized and maximum recoveries were reached using methanol under the following operational conditions: 100ºC, 1500 psi, extraction time of 5 min, one extraction cycle, flush volume of 60% and purge time of 120 s. Pressurized liquid extraction recoveries were higher than 88% for all the compounds except for carbamazepine (55%). The repeatability and reproducibility between days, expressed as relative standard deviation (n = 5), were lower than 6 and 10%, respectively. The detection limits for all compounds were lower than 12.5 μg/kg of dry weight. The method was applied to determine benzodiazepines and barbiturates in sewage sludge from urban sewage treatment plants, and carbamazepine showed the highest concentration (7.9-18.9 μg/kg dry weight).
authors.affiliation: Department of Analytical Chemistry and Organic Chemistry, Universitat Rovira i Virgili, Tarragona, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Arbeláez
authors.forename: Judith
authors.initials: J
authors.lastname: Granados
authors.forename: Francesc
authors.initials: F
authors.lastname: Borrull
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Marcé
authors.forename: Eva
authors.initials: E
authors.lastname: Pocurull
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006993:Hypnotics and Sedatives / Q000737:chemistry* / Q000302:isolation & purification*; D059625:Liquid-Liquid Extraction / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D006993:Hypnotics and Sedatives; D012722:Sewage
keywords: Barbiturates; Benzodiazepines; Core-Shell particle columns; Pressurized liquid extraction; Sewage sludge