RT Journal Article T1 Ultrasound-assisted dispersive micro-solid phase extraction of Pb(II) in water samples with in situ synthesis of magnetic Fe3O4-PbS nanocomposites followed by electrothermal atomic absorption spectrometry determination A1 Sanmartín, Raquel A1 Romero Rivas, Vanesa A1 Lavilla Beltran, Maria Isela A1 Bendicho Hernandez, Jose Carlos K1 2301 Química Analítica K1 3308 Ingeniería y Tecnología del Medio Ambiente AB Herein, an ultrasound-assisted dispersive magnetic micro-solid phase extraction (DM-μSPE) approach, along with electrothermal atomic absorption spectrometry (ETAAS) for the determination of lead at trace level in spring, well, river mineral and tap water samples was developed. The extraction step is based on the synthesis of PbS, following the sonochemical decomposition of L-cysteine used as sulphide precursor and its anchoring onto bare magnetite nanoparticles yielding the Fe3O4@PbS nanocomposite. Overall, DM-μSPE with in situ precipitation of PbS and retention onto magnetic sorbent requires a time as short as 6 min. After trapping Pb(II) as PbS, the magnetic nanocomposite was easily separated from the aqueous matrix by applying an external magnetic field and analyzed by ETAAS following slurry sampling. Different parameters involved in both the sorbent preparation/extraction and Pb quantification were optimized. Under optimal conditions, the method showed a detection limit of 0.02 μg L−1 Pb and a quantification limit of 0.07 μg L−1 Pb. The repeatability, expressed as relative standard deviation was 2% (for 0.6 μg L−1; n = 3). An experimental enrichment factor of 79 and an extraction efficiency of 99% were obtained. Finally, the method was applied for the determination of ultratrace levels of Pb(II) in spring, well, river mineral and tap water samples, showing quantitative recoveries in the range of 95–100%. PB Spectrochimica Acta Part B Atomic Spectroscopy SN 05848547 YR 2022 FD 2022-02 LK http://hdl.handle.net/11093/3001 UL http://hdl.handle.net/11093/3001 LA eng NO Spectrochimica Acta Part B Atomic Spectroscopy, 188, 106349 (2022) NO Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG NO Agencia Estatal de Investigación | Ref. RTI2018-093697-B-I00 DS Investigo RD 23-sep-2023