title: Ultra-performance liquid chromatography MS/MS method for the determination of parabens in compost from sewage sludge: comparison of the efficiency of two extraction techniques.
abstract: The efficiency of two extraction techniques--ultrasound-assisted extraction and pressurized liquid extraction--are compared and evaluated in the determination of parabens in compost samples. The extraction parameters for each technique were accurately optimized. The selected compounds were detected and quantified using ultra-performance LC MS/MS, operating in negative ESI and in SRM mode. The analytes were separated in less than 5 min. Ethylparaben (ring-(13)C6 labeled) was used as an internal standard. Two selective, sensitive, and accurate analytical methods were developed and validated. The LODs of the methods ranged from 3 to 7 ng/g and the LOQs from 10 to 23 ng/g, while inter- and intraday variability was under 6% in all cases. The methods were validated separately by using matrix-matched calibration and recovery assays with spiked samples. Recovery rates ranged from 94.0 to 105.0%. Compost samples were taken from different composting plants. Although the statistical comparison demonstrated no statistically significant differences between the two extraction techniques, the method based on pressurized liquid extraction was more sensitive than the ultrasound extraction based method.
authors.affiliation: Department of Analytical Chemistry, Research Group of Analytical Chemistry and Life Sciences, Campus of Fuentenueva, University of Granada, Granada, Spain.
authors.forename: Julio César
authors.initials: JC
authors.lastname: Benítez-Villalba
authors.forename: Alberto
authors.initials: A
authors.lastname: Zafra-Gómez
authors.forename: Noemí
authors.initials: N
authors.lastname: Dorival-García
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Camino-Sánchez
authors.forename: Samuel
authors.initials: S
authors.lastname: Cantarero
authors.forename: José Luis
authors.initials: JL
authors.lastname: Vílchez
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D059625:Liquid-Liquid Extraction / Q000295:instrumentation / Q000379:methods*; D010226:Parabens / Q000032:analysis* / Q000302:isolation & purification; D012722:Sewage / Q000032:analysis*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods; D014465:Ultrasonics / Q000379:methods
chemical_list: D010226:Parabens; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants
keywords: Compost; Endocrine-disrupting chemicals; LC MS/MS; Pressurized liquid extraction; Ultrasound-assisted extraction