title: Determination of fluoroquinolone antibacterial agents in sewage sludge and sludge-treated soil using accelerated solvent extraction followed by solid-phase extraction.
abstract: A method for the quantitative determination of humanuse fluoroquinolone antibacterial agents (FQs) ciprofloxacin and norfloxacin in sewage sludge and sludge-treated soil samples was developed. The accelerated solvent extraction was optimized with regard to solvents and operational parameters, such as temperature, pressure, and extraction time. A 50 mM aqueous phosphoric acid/ acetonitrile mixture (1:1) was found to be optimum in combination with an extraction temperature of 100 degrees C at 100 bar, during 60 and 90 min for sewage sludge and sludge-treated soil samples, respectively. A cleanup step using solid-phase extraction substantially improved the selectivity of the method. Overall recovery rates for FQs ranged from 82 to 94% for sewage sludge and from 75 to 92% for sludge-treated soil, with relative standard deviations between 8 and 11%. Limits of quantification were 0.45 and 0.18 mg/kg of dry matter for sewage sludge and sludge-treated soils, respectively. The presented method was successfully applied to untreated and anaerobically digested sewage sludges and sludge-treated soils. Ciprofloxacin and norfloxacin were determined in sewage sludges from several wastewater treatment plants with concentrations ranging from 1.40 to 2.42 mg/kg of dry matter. Therefore, contrary to what may be expected for human-use pharmaceuticals, FQs may reach the terrestrial environment as indicated by the occurrence of FQs in topsoil samples from experimental fields, to which sewage sludge had been applied.
authors.affiliation: Swiss Federal Institute for Environmental Science and Technology (EA WAG), Dübendorf.
authors.forename: Eva M
authors.initials: EM
authors.lastname: Golet
authors.forename: Adrian
authors.initials: A
authors.lastname: Strehler
authors.forename: Alfredo C
authors.initials: AC
authors.lastname: Alder
authors.forename: Walter
authors.initials: W
authors.lastname: Giger
mesh_terms: D000890:Anti-Infective Agents / Q000032:analysis*; D002623:Chemistry Techniques, Analytical / Q000379:methods; D002627:Chemistry, Physical / Q000379:methods; D002939:Ciprofloxacin / Q000032:analysis*; D006801:Humans; D008506:Medical Waste / Q000032:analysis; D009643:Norfloxacin / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012722:Sewage / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis; D012997:Solvents
chemical_list: D000890:Anti-Infective Agents; D008506:Medical Waste; D012722:Sewage; D012989:Soil Pollutants; D012997:Solvents; D002939:Ciprofloxacin; D009643:Norfloxacin