|Title||Chemical analysis in the field by x-ray fluorescence spectroscopy, an example from the Lac Dasserat study, Quebec|
|Author||Grenier, A; McNeil, R; Alpay, S|
|Source||Geological Survey of Canada, Scientific Presentation 17, 2013, 1 sheet, https://doi.org/10.4095/292871|
|Publisher||Natural Resources Canada|
|Area||Lac Dasserat; Rouyn-Noranda|
|Lat/Long WENS||-79.5333 -79.2000 48.3500 48.1667|
|Subjects||geochemistry; environmental geology; hydrogeology; stream sediment geochemistry; geochemical analyses; analyses; stream water geochemistry; geochemical analyses; geochemical surveys; trace element
geochemistry; major element geochemistry; stream sediment samples; sediments; silts; environmental analysis; environmental studies; environmental impacts; acid mine drainage; acid drainage; Aldermac Mine|
|Illustrations||location maps; plots; photographs|
|Program||Tools for environmental impacts and adaptation for metal mining, Environmental Geoscience|
|Released||2013 09 12|
|Abstract||Two types of X-ray fluorescence (XRF) spectrometers were deployed on site to analyse stream and lake surface waters as well as lake sediment chemistry. Water and sediment samples were collected
downstream of the abandoned Aldermac VMS mine, 15 km west of Rouyn-Noranda, Quebec. The goals of the study are to identify the spatial and temporal extent of metal contamination as a result of decades of acid mine drainage from the Aldermac site and
to evaluate and compare rapid data collection in the field by XRF with laboratory-based inductively coupled plasma mass spectrometry (ICP-MS) for Cu, Zn and Mn.|
Water chemistry was determined by a Bruker S2 PICOFOX total reflection X-ray
fluorescence (TXRF) spectrometer from filtered and acidified samples spiked with Ga as an internal standard. The instrument demonstrated high accuracy for the certified reference material (CRM), TMDA-51.3. Data obtained for Cu, Zn and Mn
concentrations were within acceptable limits of the certified values. Analytical results by ICP-MS of lake and stream samples showed excellent correlation (r2 > 0.99) with field analysis by TXRF for the three metals.
Lake sediment geochemistry was
determined by a handheld Olympus Innov-X Delta Premium DP-4000 X-ray fluorescence spectrometer. Sample preparation in the field included drying and reducing samples to a powder. High accuracy of analytical results was obtained using CRM LKSD-1 for
Cu, Zn and Mn. Comparison of Cu, Zn and Mn concentrations determined by handheld XRF with ICP-MS analyses of aqua-regia and four-acid digestions of sediment samples also yielded excellent correlations (r2 > 0.98).
Results suggest that TXRF
analysis of surface waters and handheld XRF analysis of lake sediments provide practical and accurate diagnostic tools for rapid field analysis of Cu, Zn and Mn concentrations. Overnight results allowed quick testing of scientific hypotheses (e.g.,
contaminant flowpaths, locations of potential control sites) without waiting for laboratory results (e.g., by ICP). Rapid data acquisition
also provided guidance for and optimization of daily sampling strategies during field work. Rapid
field-based analytical results from XRF spectrometry have the potential to provide efficiencies for environmental risk assessments conducted by industrial project proponents and environmental consultants.
|Summary||(Plain Language Summary, not published)|
The major goal of the Lac Dasserat study is to demonstrate novel tools for risk assessment of receiving environments downstream of metal mining (Tools
for Metal Mining Environmental Impact Assessment project; Environmental Geoscience Program). Two types of X-ray fluorescence (XRF) spectrometry techniques were deployed in the field to measure the chemistry of streams, lake water and aquatic
sediments on site. Rapid (24 hour) field results from XRF analyses were consistent with results for zinc, copper and manganese by traditional laboratory techniques that can take weeks or months to obtain (e.g., inductively-coupled plasma mass
spectrometry or optical emission spectroscopy). XRF analyses allowed rapid testing of scientific hypotheses and daily optimization of sampling strategies while in the field. Mine project proponents and environmental consultants could also find
efficiencies for environmental risk assessment by using rapid field-based XRF analytical techniques.