Determination of the concentration of carbonic species in natural waters: results from a world-wide proficiency test
Article
Article Title | Determination of the concentration of carbonic species in natural waters: results from a world-wide proficiency test |
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ERA Journal ID | 1730 |
Article Category | Article |
Authors | Verma, Mahendra P. (Author), Portugal, Enrique (Author), Gangloff, Sophie (Author), Armienta, Mana Aurora (Author), Chandrasekharam, Dornadula (Author), Sanchez, Mayela (Author), Renderos, Roberto E. (Author), Juanco, Miguel (Author) and van Geldern, Robert (Author) |
Journal Title | Geostandards and Geoanalytical Research |
Journal Citation | 39 (2), pp. 233-255 |
Number of Pages | 23 |
Year | 2015 |
Place of Publication | United States |
ISSN | 1639-4488 |
1751-908X | |
Digital Object Identifier (DOI) | https://doi.org/10.1111/j.1751-908X.2014.00306.x |
Web Address (URL) | https://onlinelibrary.wiley.com/doi/full/10.1111/j.1751-908X.2014.00306.x |
Abstract | The results of an international interlaboratory proficiency test for the determination of carbonic species are presented. Eight laboratories analysed twelve water samples (four synthetic waters, one lake water, four geothermal waters, one seawater and two petroleum waters) by two methods: (a) individual laboratory analytical procedure and (b) acid-base titration curves in tabular form following a standardised protocol. In case (b), the concentrations of carbonic species were calculated by the organiser using the (1) Hydrologists' method, (2) Geochemists' method and/or (3) initial pH and total alkalinity method. For synthetic waters, the averaged % trueness and precision of measurement of the two methods were (trueness = 7.6, precision = 9.4) and (9.0, 3.4) for total alkalinity, and (6.6, 31.0) and (7.8, 6.1) for carbonic alkalinity, respectively. This indicates that the total alkalinity calculation procedure is in general correct in the individual laboratory method, but the carbonic alkalinity calculation procedure has serious problems. The measurements of total alkalinity for lake and seawaters were in agreement in both the methods; however, the individual laboratory measurement method for geothermal and petroleum waters was conceptually incorrect. Thus, the analytical procedures for the determination of carbonic species were reviewed. To apply the Hydrologists' and/or Geochemists' methods, the location of NaHCO3EP and H2CO3EP is necessary, even for samples with pH lower than that of NaHCO3EP, and a backward titration curve after complete removal of CO2 must be performed. The initial pH and total alkalinity method is appropriate where a complete analysis of species that contribute to the alkalinity is known. |
Keywords | acid-base titration, analytical method, interlaboratory comparison, natural waters |
ANZSRC Field of Research 2020 | 419999. Other environmental sciences not elsewhere classified |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | Electrical Research Institute, Mexico |
University of Strasbourg, France | |
National Autonomous University of Mexico, Mexico | |
Indian Institute of Technology, India | |
Cerro Prieto Geothermal Power Plant, Mexico | |
University of Valladolid, Spain | |
Institute of Agricultural Sciences, Spain | |
University of Erlangen–Nuremberg, Germany | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q522q/determination-of-the-concentration-of-carbonic-species-in-natural-waters-results-from-a-world-wide-proficiency-test
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