title: Innovative combination of QuEChERS extraction with on-line solid-phase extract purification and pre-concentration, followed by liquid chromatography-tandem mass spectrometry for the determination of non-steroidal anti-inflammatory drugs and their metabolites in sewage sludge.
abstract: For the first time QuEChERS extraction of sewage sludge was combined with the automatic solid-phase pre-concentration and purification of the extract (following indicated as SPE) and LC-MS/MS analysis, for the determination of the non-steroidal anti-inflammatory drugs acetylsalicylic acid (ASA), diclofenac (DIC), fenbufen (FEN), flurbiprofen (FLU), ketoprofen (KET), ibuprofen (IBU) and naproxen (NAP), and their metabolites salicylic acid (SAL), 4'-hydroxydiclofenac (4'-HYDIC), 1-hydroxyibuprofen (1-HYIBU), 2-hydroxyibuprofen (2-HYIBU), 3-hydroxyibuprofen (3-HYIBU) and o-desmethylnaproxen (O-DMNAP). Various commercial pellicular stationary phases (i.e. silica gel functionalized with octadecyl, biphenyl, phenylhexyl and pentafluorophenyl groups) were preliminarily investigated for the resolution of target analytes and different sorbent phases (i.e. octyl or octadecyl functionalized silica gel and a polymeric phase functionalized with N-benzylpyrrolidone groups) were tested for the SPE phase. The optimized method involves the QuEChERS extraction of 1 g of freeze-dried sludge with 15 mL of water/acetonitrile 1/2 (v/v), the SPE of the extract with the N-benzylpyrrolidone polymeric phase and the water/acetonitrile gradient elution on the pentafluorophenyl stationary phase at room temperature. Matrix effect was always suppressive and in most cases low, being it ≤20% for ASA, DIC, FLU, KET, IBU, 1-HYIBU, 2-HYIBU, 3-HYIBU, NAP and O-DMNAP, and included in the range of 35-47% for the other analytes. Recoveries were evaluated at three spiking levels, evidencing almost quantitative values for HYIBUs and O-DMNAP; for ASA, SAL and KET the recoveries were included in between 50 and 76%, whereas for the other compounds they ranged from 36% to 55%. The proposed method showed better analytical performances than those so far published, being suitable for target compound determination in real samples from tens of pg g(-1) to ng g(-1) of freeze-dried sludge, with a total analysis time of 30 min per sample.
authors.affiliation: Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy; Department of Chemistry, University of Turin, Via Pietro Giuria 5, 10125 Turin, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Rossini
authors.affiliation: Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Ciofi
authors.affiliation: Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Ancillotti
authors.affiliation: Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Checchini
authors.affiliation: Department of Chemistry, University of Turin, Via Pietro Giuria 5, 10125 Turin, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: Bruzzoniti
authors.affiliation: Department of Chemistry, University of Turin, Via Pietro Giuria 5, 10125 Turin, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Rivoira
authors.affiliation: GIDA S.p.A., Via di Baciacavallo 36, 59100 Prato, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Fibbi
authors.affiliation: Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Orlandini
authors.affiliation: Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy. Electronic address: delbubba@unifi.it.
authors.forename: M
authors.initials: M
authors.lastname: Del Bubba
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis* / Q000378:metabolism; D002853:Chromatography, Liquid; D012722:Sewage / Q000032:analysis*; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D012722:Sewage
keywords: Drug metabolites; Liquid chromatography-tandem mass spectrometry; Non-steroidal anti-inflammatory drugs; QuEChERS; Sewage sludge; Solid-phase pre-concentration and purification