title: Electroadsorption-assisted direct determination of trace arsenic without interference using transmission X-ray fluorescence spectroscopy.
abstract: An analytical technique based on electroadsorption and transmission X-ray fluorescence (XRF) for the quantitative determination of arsenic in aqueous solution with ppb-level limits of detection (LOD) is proposed. The approach uses electroadsorption to enhance the sensitivity and LOD of the arsenic XRF response. Amine-functionalized carbonaceous microspheres (NH2-CMSs) are found to be the ideal materials for both the quantitative adsorption of arsenic and XRF analysis due to the basic amine sites on the surface and their noninterference in the XRF spectrum. In electroadsorptive X-ray fluorescence (EA-XRF), arsenic is preconcentrated by a conventional three-electrode system with a positive electricity field around the adsorbents. Then, the quantification of arsenic on the adsorbents is achieved using XRF. The electroadsorption preconcentration can realize the fast transfer of arsenic from the solution to the adsorbents and improve the LOD of conventional XRF compared with directly determining arsenic solution by XRF alone. The sensitivity of 0.09 cnt ppb(-1) is obtained without the interferences from coexisted metal ions in the determination of arsenic, and the LOD is found to be 7 ppb, which is lower than the arsenic guideline value of 10 ppb given by the World Health Organization (WHO). These results demonstrated that XRF coupled with electroadsorption was able to determine trace arsenic in real water sample.
authors.affiliation: †Department of Chemistry, University of Science and Technology of China, Hefei 230026, People's Republic of China.|‡Nanomaterials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: Tian-Jia
authors.initials: TJ
authors.lastname: Jiang
authors.affiliation: ‡Nanomaterials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Guo
authors.affiliation: ‡Nanomaterials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: Jin-Huai
authors.initials: JH
authors.lastname: Liu
authors.affiliation: †Department of Chemistry, University of Science and Technology of China, Hefei 230026, People's Republic of China.|‡Nanomaterials and Environmental Detection Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: Xing-Jiu
authors.initials: XJ
authors.lastname: Huang
mesh_terms: D000327:Adsorption; D000586:Amination; D001151:Arsenic / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D004566:Electrodes; D005618:Fresh Water / Q000032:analysis; D057230:Limit of Detection; D008670:Metals / Q000737:chemistry; D008863:Microspheres; D013052:Spectrometry, X-Ray Emission / Q000295:instrumentation / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D002244:Carbon; D001151:Arsenic