title: Non-chromatographic speciation of toxic arsenic in vegetables by hydride generation-atomic fluorescence spectrometry after ultrasound-assisted extraction.
abstract: A non-chromatographic, sensitive and simple analytical method has been developed for the determination of toxic arsenic species in vegetable samples by hydride generation-atomic fluorescence spectrometry (HG-AFS). As(III), As(V), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) were determined by hydride generation-atomic fluorescence spectrometry using a series of proportional equations. The method is based on a single extraction of the arsenic species considered from vegetables through sonication at room temperature with H(3)PO(4) 1 mol L(-1) in the presence of 0.1% (w/v) Triton XT-114 and washing of the solid phase with 0.1% (w/v) EDTA, followed by direct measurement of the corresponding hydrides in four different experimental conditions. The limit of detection of the method was 3.1 ng g(-1) for As(III), 3.0 ng g(-1) for As(V), 1.5 ng g(-1) for DMA and 1.9 ng g(-1) for MMA, in all cases expressed in terms of sample dry weight. Recovery studies provided percentages greater than 91% for all considered species in spiked samples of chards and aubergines. Total toxic As found in the aforementioned samples was at the level of 90 ng g(-1); As(III) is followed by As(V), DMA and MMA which are the main species of As in chards being As(V) the main As compound in aubergines.
authors.affiliation: Department of Chemistry, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, 22453-900 Rio de Janeiro, RJ, Brazil.
authors.forename: Mariela N Matos
authors.initials: MN
authors.lastname: Reyes
authors.forename: M Luisa
authors.initials: ML
authors.lastname: Cervera
authors.forename: Reinaldo C
authors.initials: RC
authors.lastname: Campos
authors.forename: Miguel
authors.initials: M
authors.lastname: de la Guardia
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000145:classification; D001152:Arsenicals / Q000032:analysis*; D002101:Cacodylic Acid / Q000032:analysis*; D002845:Chromatography; D006859:Hydrogen / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013054:Spectrophotometry, Atomic; D014465:Ultrasonics; D014675:Vegetables / Q000737:chemistry*
chemical_list: D001152:Arsenicals; D010756:Phosphoric Acids; D006859:Hydrogen; D002101:Cacodylic Acid; C020300:monomethylarsonic acid; D001151:Arsenic