title: Evaluation of hexavalent chromium extraction method EPA method 3060A for soils using XANES spectroscopy.
abstract: Hexavalent chromium (Cr(VI)) occurrence in soils is generally determined using an extraction step to transfer it to the liquid phase where it is more easily detected and quantified. In this work, the performance of the most common extraction procedure (EPA Method 3060A) using NaOH-Na(2)CO(3) solutions is evaluated using X-ray absorption near edge structure spectroscopy (XANES), which enables the quantification of Cr(VI) directly in the solid state. Results obtained with both methods were compared for three solid samples with different matrices: a soil containing chromite ore processing residue (COPR), a loamy soil, and a paint sludge. Results showed that Cr(VI) contents determined by the two methods differ significantly, and that the EPA Method 3060A procedure underestimated the Cr(VI) content in all studied samples. The underestimation is particularly pronounced for COPR. Low extraction yield for EPA Method 3060A was found to be the main reason. The Cr(VI) present in COPR was found to be more concentrated in magnetic phases. This work provides new XANES analyses of SRM 2701 and its extraction residues for the purpose of benchmarking EPA 3060A performance.
authors: Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, IPREM, UMR CNRS 5254, Université de Pau et des Pays de l'Adour, Hélioparc Pau-Pyrénées, 2, avenue Pierre Angot, 64053 Pau Cedex 9, France. malherbe.julien@hotmail.fr
authors: Julien
authors: J
authors: Malherbe
authors: Marie-Pierre
authors: MP
authors: Isaure
authors: Fabienne
authors: F
authors: Séby
authors: Russell P
authors: RP
authors: Watson
authors: Pablo
authors: P
authors: Rodriguez-Gonzalez
authors: Paul E
authors: PE
authors: Stutzman
authors: Clay W
authors: CW
authors: Davis
authors: Chiara
authors: C
authors: Maurizio
authors: Nora
authors: N
authors: Unceta
authors: John R
authors: JR
authors: Sieber
authors: Stephen E
authors: SE
authors: Long
authors: Olivier F X
authors: OF
authors: Donard
mesh_terms: D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods; D002857:Chromium / Q000032:analysis* / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D014481:United States; D014484:United States Environmental Protection Agency; D056928:X-Ray Absorption Spectroscopy
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002857:Chromium; C074702:chromium hexavalent ion