title: Can sample treatments based on advanced oxidation processes assisted by high-intensity focused ultrasound be used for toxic arsenic determination in human urine by flow-injection hydride-generation atomic absorption spectrometry?
abstract: Two advanced oxidation processes (AOPs), based on high-intensity focused ultrasound (HIFU), namely, KMnO(4)/HCl/HIFU and H(2)O(2)/HCl/HIFU are studied and compared for the determination of toxic arsenic in human urine [As(III)+As(V)+MMA+DMA] by flow-injection hydride-generation atomic absorption spectrometry (FI-HG-AAS). The KMnO(4)/HCl/HIFU procedure was found to be adequate for organic matter degradation in human urine. l-cysteine (letra minuscula) was used for As reduction to the trivalent state. The new procedure was assessed with seven urines certified in different As species. Results revealed that with KMnO(4)/HCl/HIFU plus l-cysteine the toxic arsenic can be accurately measured in human urine whilst the H(2)O(2)/HCl/HIFU procedure underestimates toxic As. DMA and MMA degradation in urine were observed, due to the effects of the ultrasonic field. Recoveries for As(III), As(V), MMA and DMA were within the certified ranges. Arsenobetaine was not degraded by the AOPs. The new procedure adheres well to the principles of analytical minimalism: (i) low reagent consumption, (ii) low reagent concentration, (iii) low waste production and (iv) low amount of time required for sample preparation and analysis.
authors.affiliation: REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Correia
authors.forename: M
authors.initials: M
authors.lastname: Galesio
authors.forename: H
authors.initials: H
authors.lastname: Santos
authors.forename: R
authors.initials: R
authors.lastname: Rial-Otero
authors.forename: C
authors.initials: C
authors.lastname: Lodeiro
authors.forename: A
authors.initials: A
authors.lastname: Oehmen
authors.forename: Antonio C L
authors.initials: AC
authors.lastname: Conceição
authors.forename: J L
authors.initials: JL
authors.lastname: Capelo