title: Speciation of inorganic arsenic in drinking water by wavelength-dispersive X-ray fluorescence spectrometry after in situ preconcentration with miniature solid-phase extraction disks.
abstract: A rapid and simple method using wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry after in situ solid-phase extraction (SPE) was developed for the speciation and evaluation of the concentration of inorganic arsenic (As) in drinking water. The method involves the simultaneous collection of As(III) and As(V) using 13 mm ϕ SPE miniature disks. The removal of Pb(2+) from the sample water was first conducted to avoid the overlapping PbLα and AsKα spectra on the XRF spectrum. To this end, a 50 mL aqueous sample (pH 5-9) was passed through an iminodiacetate chelating disk. The filtrate was adjusted to pH 2-3 with HCl, and then ammonium pyrrolidine dithiocarbamate solution was added. The solution was passed through a hydrophilic polytetrafluoroethylene filter placed on a Zr and Ca loaded cation-exchange disk at a flow rate of 12.5 mL min(-1) to separate As(III)-pyrrolidine dithiocarbamate complex and As(V). Each SPE disk was affixed to an acrylic plate using adhesive cellophane tape, and then examined by WDXRF spectrometry. The detection limits of As(III) and As(V) were 0.8 and 0.6 μg L(-1), respectively. The proposed method was successfully applied to screening for As speciation and concentration evaluation in spring water and well water.
authors.affiliation: Department of Applied Chemistry, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki 214-8571, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Hagiwara
authors.affiliation: Organization for the Strategic Coordination of Research and Intellectual Properties, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki 214-8571, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Inui
authors.affiliation: Department of Applied Chemistry, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki 214-8571, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Koike
authors.affiliation: Department of Applied Chemistry, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki 214-8571, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Aizawa
authors.affiliation: Department of Applied Chemistry, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki 214-8571, Japan. Electronic address: toshina@isc.meiji.ac.jp.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D060766:Drinking Water / Q000032:analysis*; D007474:Ion Exchange; D007854:Lead / Q000737:chemistry; D011138:Polytetrafluoroethylene / Q000737:chemistry; D052616:Solid Phase Extraction; D013052:Spectrometry, X-Ray Emission; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D060766:Drinking Water; D014874:Water Pollutants, Chemical; D007854:Lead; D011138:Polytetrafluoroethylene; D015040:Zirconium; D001151:Arsenic; D002118:Calcium
keywords: Arsenic; In situ preconcentration; Solid-phase extraction; Speciation; X-ray fluorescence spectrometry