title: Assessing arsenic and selenium in a single nail clipping using portable X-ray fluorescence.
abstract: The feasibility of measuring arsenic and selenium contents in a single nail clipping was investigated using a small-focus portable X-ray fluorescence (XRF) instrument with monochromatic excitation beams. Nail clipping phantoms supplemented with arsenic and selenium to produce materials with 0, 5, 10, 15, and 20µg/g were used for calibration purposes. In total, 10 different clippings were analyzed at two different measurement positions. Energy spectra were fit with detection peaks for arsenic Kα, selenium Kα, arsenic Kβ, selenium Kβ, and bromine Kαcharacteristic X-rays. Data analysis was performed under two distinct conditions of fitting constraint. Calibration lines were established from the amplitude of each of the arsenic and selenium peaks as a function of the elemental contents in the clippings. The slopes of the four calibration lines were consistent between the two conditions of analysis. The calculated minimum detection limit (MDL) of the method, when considering the Kαpeak only, ranged from 0.210±0.002µg/g selenium under one condition of analysis to 0.777±0.009µg/g selenium under another. Compared with previous portable XRF nail clipping studies, MDLs were substantially improved for both arsenic and selenium. The new measurement technique had the additional benefits of being short in duration (~3min) and requiring only a single nail clipping. The mass of the individual clipping used did not appear to play a major role in signal strength, but positioning of the clipping is important.
authors.affiliation: Physics Department, Mount Allison University, Sackville, NB, Canada. Electronic address: dfleming@mta.ca.
authors.forename: David E B
authors.initials: DE
authors.lastname: Fleming
authors.affiliation: Physics Department, Mount Allison University, Sackville, NB, Canada.
authors.forename: Michel N
authors.initials: MN
authors.lastname: Nader
authors.affiliation: Physics Department, Mount Allison University, Sackville, NB, Canada.
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Foran
authors.affiliation: Physics Department, Mount Allison University, Sackville, NB, Canada.
authors.forename: Craig
authors.initials: C
authors.lastname: Groskopf
authors.affiliation: Physics Department, Mount Allison University, Sackville, NB, Canada.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Reno
authors.affiliation: Physics Department, Mount Allison University, Sackville, NB, Canada.
authors.forename: Chris S
authors.initials: CS
authors.lastname: Ware
authors.affiliation: Department of Environmental Health Sciences, School of Public Health, The University at Albany, P.O. Box 509, Albany, NY 12201, USA.
authors.forename: Mina
authors.initials: M
authors.lastname: Tehrani
authors.affiliation: Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201, USA; Department of Environmental Health Sciences, School of Public Health, The University at Albany, P.O. Box 509, Albany, NY 12201, USA.
authors.forename: Diana
authors.initials: D
authors.lastname: Guimarães
authors.affiliation: Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201, USA; Department of Environmental Health Sciences, School of Public Health, The University at Albany, P.O. Box 509, Albany, NY 12201, USA.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Parsons
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000633:toxicity; D002138:Calibration; D004781:Environmental Exposure; D005240:Feasibility Studies; D006801:Humans; D057230:Limit of Detection; D009262:Nails / Q000737:chemistry*; D019047:Phantoms, Imaging; D012643:Selenium / Q000032:analysis* / Q000633:toxicity; D013052:Spectrometry, X-Ray Emission / Q000295:instrumentation* / Q000706:statistics & numerical data
chemical_list: D012643:Selenium; D001151:Arsenic
keywords: Arsenic; Portable X-ray fluorescence; Selenium