title: Combining single-particle inductively coupled plasma mass spectrometry and X-ray absorption spectroscopy to evaluate the release of colloidal arsenic from environmental samples.
abstract: Detection and sizing of natural colloids involved in the release and transport of toxic metals and metalloids is essential to understand and model their environmental effects. Single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) was applied for the detection of arsenic-bearing particles released from mine wastes. Arsenic-bearing particles were detected in leachates from mine wastes, with a mass-per-particle detection limit of 0.64 ng of arsenic. Conversion of the mass-per-particle information provided by SP-ICP-MS into size information requires knowledge of the nature of the particles; therefore, synchrotron-based X-ray absorption spectroscopy (XAS) was used to identify scorodite (FeAsO4·2H2O) as the main species in the colloidal particles isolated by ultrafiltration. The size of the scorodite particles detected in the leachates was below 300-350 nm, in good agreement with the values obtained by TEM. The size of the particles detected by SP-ICP-MS was determined as the average edge of scorodite crystals, which show a rhombic dipyramidal form, achieving a size detection limit of 117 nm. The combined use of SP-ICP-MS and XAS allowed detection, identification, and size determination of scorodite particles released from mine wastes, suggesting their potential to transport arsenic. Graphical abstract Analytical approach for the detection and size characterization of As-bearing particles by SP-ICP-MS and XAS in environmental samples.
authors: National Museum of Natural Sciences, CSIC, Jose Gutierrez Abascal 2, 28006, Madrid, Spain.
authors: Miguel Angel
authors: MA
authors: Gomez-Gonzalez
authors: Group of Analytical Spectroscopy and Sensors (GEAS), Institute of Environmental Sciences (IUCA), University of Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain.
authors: Eduardo
authors: E
authors: Bolea
authors: Environmental Systems Program, University of California, Merced, CA, 95343, USA.
authors: Peggy A
authors: PA
authors: O'Day
authors: National Museum of Natural Sciences, CSIC, Jose Gutierrez Abascal 2, 28006, Madrid, Spain.
authors: Javier
authors: J
authors: Garcia-Guinea
authors: National Museum of Natural Sciences, CSIC, Jose Gutierrez Abascal 2, 28006, Madrid, Spain.
authors: Fernando
authors: F
authors: Garrido
authors: Group of Analytical Spectroscopy and Sensors (GEAS), Institute of Environmental Sciences (IUCA), University of Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain. flaborda@unizar.es.
authors: Francisco
authors: F
authors: Laborda
keywords: Arsenic; Colloids; SP-ICP-MS; Scorodite; Single particle; XAS