Hostname: page-component-7bb8b95d7b-dtkg6 Total loading time: 0 Render date: 2024-09-26T21:02:52.851Z Has data issue: false hasContentIssue false
  • English
  • Français

On the colorimetric measurement of aqueous Si in the presence of organic ligands and common pH buffering agents

Published online by Cambridge University Press:  05 July 2018

Thomas Rinder  and
Eric H. Oelkers
Thomas Rinder*
Affiliation:
GET/CNRS, 14 avenue Édouard Belin, 31400, Toulouse, France
Eric H. Oelkers
Affiliation:
GET/CNRS, 14 avenue Édouard Belin, 31400, Toulouse, France Earth Science, University College London, Gower Street, London WC1E 6BT, UK
*
* E-mail: rinder@get.obs-mip.fr
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The effects of the presence of ten organic ligands and common pH buffering agents – acetate, oxalate, tartrate, citrate, phthalate, EDTA, carbonate, TRIS, phosphate and borate – on aqueous Si concentration measurements made using the common molybdate blue method were quantified. The concentrations of these additives ranged from 0.01 to 0.1 mol/kg in the measured aqueous solutions. Whereas measured Si concentrations were not affected by the presence of up to 0.1 mol/kg acetate, hydrogen phthalate or TRIS, the presence of 0.1 mol/kg of all other selected additives altered substantially the measured Si concentrations using the molybdate blue method. For example the presence of 0.1 mol/kg of citrate, EDTA, and hydrogen phosphate decreased the ratio of measured to true Si concentrations to ~0.05. These variations are interpreted to stem from the formation of competing aqueous complexes in the aqueous phase limiting the formation of the characteristically blue SiMo12O404– complex.

Keywords

Si concentration measurementsmolybdate blueorganic ligandspH buffers.
Type
Research Article
Information
Mineralogical Magazine , Volume 78 , Issue 6 , November 2014 , pp. 1431 - 1436
Creative Commons
Creative Common License - CCCreative Common License - BY
© [2014] The Mineralogical Society of Great Britain and Ireland. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY) licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2014

References

Coradin, T., Eglin, D. and Livage, J. (2004) The silicomolybdic acid spectrophotometric method and its application to silicate/biopolymer interaction studies. Journal of Spectroscopy, 18, 567–576.CrossRefGoogle Scholar
Cruywagen, J.J., Rohwer, E.A. and Wessels, G.F.S. (1995) Molybdenum(VI) complex formation-8. Equilibria and thermodynamic quantities for the reactions with citrate. Polyhedron, 14, 3481–3493.CrossRefGoogle Scholar
Cruywagen, J.J., Rohwer, E.A. and van de Water, R.F. (1997) Molybdenum(VI) complex formation. Equilibria and thermodynamic quantities for the reactions with malate. Polyhedron, 16, 243–251.CrossRefGoogle Scholar
Debiemme-Chouvy, C. and Quennoy, A. (2004) Anodic photodissolution of n-lnp u.d.r electroless conditions. Electrochimica Acta, 49, 3129–3136.CrossRefGoogle Scholar
Declercq, J., Bosc, O. and Oelkers, E.H. (2013) Do organic ligands affect forsterite dissolution rates? Applied Geochemistry, 39, 69–77.Google Scholar
Dove, P.M. (1999) The dissolution kinetics of quartz in aqueous mixed cation solutions. Geochimica et Cosmochimica Acta, 63, 3715–3727.CrossRefGoogle Scholar
Fanning, K., and Pilson, M. (1973) On the spectrophotometric determination of dissolved silica in natural waters. Analytical Chemistry, 45, 136–140.CrossRefGoogle ScholarPubMed
Foulger, J.H. (1927) The colorimetric estimation of silicon in tissues by isaacs’ method. Journal of the American Chemical Society, 49, 429–435.CrossRefGoogle Scholar
Froelich, P.N. and Pilson, M.E.Q. (1978) Systematic absorbance errors with technicon autoanalyzer II colorimeters. Water Research, 12, 599–603.CrossRefGoogle Scholar
Galhardo, C.X. and Masini, J.C. (2000) Spectrophotometric determination of phosphate and silicate by sequential injection using molybdenum blue chemistry. Analytica Chimica Acta, 417, 191–200.CrossRefGoogle Scholar
Govett, G.J.S. (1961) Critical factors in the colorimetric determination of silica. Analytica Chimica Acta, 25, 69–80.CrossRefGoogle Scholar
He, Z.L., Baligar, V.C., Ritchey, K.D. and Martens, D.C. (1998) Determination of soluble phosphorus in the presence of organic ligands or fluoride. Soil Science Society of America Journal, 62, 1538–1541.CrossRefGoogle Scholar
Icopini, G.A., Brantley, S.L. and Heaney, P.J. (2005) Kinetics of silica oligomerization and nanocolloid formation as a function of pH and ionic strength at 25ºC. Geochimica et Cosmochimica Acta, 69, 293–303.CrossRefGoogle Scholar
Iler, R.K. (1979) The Chemistry of Silica – Solubility, Polymerization, Colloid and Surface Properties, and Biochemistry. John Wiley & Sons, Inc., New Jersey, USA.Google Scholar
Lide, D.R. (1997) CRC Handbook of Chemistry and Physics. CRC Press Boca Raton, Florida, U.S.A.Google Scholar
Mullin, J.B. and Riley, J.P. (1955) The colorimetric determination of silicate with special reference to sea and natural waters. Analytica Chimica Acta, 12, 162–176.CrossRefGoogle Scholar
Neal, C., Neal, M. and Wickham, H. (2000) Phosphate measurement in natural waters: Two examples of analytical problems associated with silica interference using phosphomolybdic acid methodologies. Science of the Total Environment, 251–252, 511–522.CrossRefGoogle Scholar
Oelkers, E.H., Schott, J., Gauthier, J.-M. and Herrero- Roncal, T. (2008) An experimental study of the dissolution mechanism and rates of muscovite. Geochimica et Cosmochimica Acta, 72, 4948–4961.CrossRefGoogle Scholar
Pokrovski, G.S. and Schott, J. (1998) Experimental study of the complexation of silicon and germanium with aqueous organic species: Implications for germanium and silicon transport and Ge/Si ratio in natural waters. Geochimica et Cosmochimica Acta, 62, 3413–3428.CrossRefGoogle Scholar
Samotus, A., Kanas, A., Dudek, M., Gryboś, R. and Hodorowicz, E. (1991) 1:1 molybdenum(VI) citric acid complexes. Transition Metal Chemistry, 16, 495–499.CrossRefGoogle Scholar
Schwartz, M.C. (1942) Photometric determination of silica in presence of phosphates. Industrial & Engineering Chemistry Analytical Edition, 14, 893–895.CrossRefGoogle Scholar
Stewart, B.M. and Elliott, P.A.W. (1996) Systematic salt effects in the automated determination of nutrients in seawater. Water Research, 30, 869–874.CrossRefGoogle Scholar
Tréguer, P. and Le Corre, P. (1975) Manuel d’analyse des sels nutrifs dans l’eau de mer: Utilisation de l’autoanalyzer II technicon (r). Université de Bretagne occidentale, France.Google Scholar
Truesdale, V.W. and Smith, C.J. (1975) The formation of molybdosilicic acids from mixed solutions of molybdate and silicate. Analyst, 100, 203–212.CrossRefGoogle Scholar
Wei, L.L., Chen, C. R. and Xu, Z.H. (2009) The effect of low-molecular-weight organic acids and inorganic phosphorus concentration on the determination of soil phosphorus by the molybdenum blue reaction. Biology and Fertility of Soils, 45, 775–779.CrossRefGoogle Scholar
Welch, S.A. and Ullman, W.J. (2000) The temperature dependence of bytownite feldspar dissolution in neutral aqueous solutions of inorganic and organic ligands at low temperature (5–35ºC). Chemical Geology, 167, 37–354.CrossRefGoogle Scholar
Wolf, A.M. and Baker, D.E. (1990) Colorimetric method for phosphorus measurement in ammonium oxalate soil extracts. Communications in Soil Science and Plant Analysis, 21, 2257–2263.CrossRefGoogle Scholar
Zhang, R.-H., Zhou, X.-W., Guo, Y.-C., Chen, M.-L., Cao, Z.-X., Chow, Y.L. and Zhou, Z.-H. (2013) Crystalline and solution chemistry of tetrameric and dimeric molybdenum(VI) citrato complexes. Inorganica Chimica Acta, 406, 27–36.CrossRefGoogle Scholar