EFFICIENCY OF WET AND DRY DIGESTION FOR DETERMINATION OF SELECTED METALS FROM COAL BY FAAS Tidža Muhić – Šaraca, Sadber Kasapovića, Dejana Brkićb a
Department of Analytical chemistry, Faculty of Science, University of Sarajevo, Sarajevo, Bosnia and Herzegovina (
[email protected]) b Department of Chemical engineering, Faculty for metallurgy and materials, University of Zenica, Zenica, Bosnia and Herzegovina
Abstract: The choice of sample digestion method is of great importance. As the translation of samples in solution is the first step in the analysis, precision and accuracy of analytical methods are dependent on it. In this work, dry and wet digestion of different coal samples were investigated in order to determine metals (Cu, Mn, Fe, Cd, Pb, and Zn) using FAAS. Wet digestion was carried out with mixtures of concentrated acid: HCl: HNO3 (3: 1), HCl: HNO3: HF (3: 1: 1), HNO3: H2O2 (5: 2), HNO3: H2O2: HF (5: 2: 1). Dry digestion was carried out with and without use of fluxes : NaOH and K2S2O7. The method used to determine the concentration of metals was a method of calibration curves. The results obtained by wet digestion differ from results obtained by dry digestion. Statistical analysis of variance (Two Way Anova) and T-test at 95% confidence level showed that there was no significant difference between the efficiency of the same digestion method for different samples of coal. Keywords: heavy metals, wet digestion, dry digestion, FAAS. References 1. B. Marin, E.I.B. Chopin, B. Jupinet, D. Gauthier, Talanta, 2008, 77, 282. 2. E. Margui, I. Queralt, M. Hidalgo, Trends in Analytical Chemistry, 2009, 28, 362. 3. S. Gaudino, C. Galas, M. Belli, S. Barbizzi, P. Zorzi, R. Jacimovic, Z. Jeran, A. Pati, U. Sansone, Accreditation and Quality Assurance, 2007, 12, 84. 4. INCDO – INOE2000, Research Institute for Analytical Instrumentation, Str. Donath No. 67, RO – 400293 Cluj – Napoca, Romania. 5. C. Brunori, I. Ipolyi, L. Macaluso, R. Morabito, Analytica Chimica Acta, 2004, 510,101. 6. J. Sucharova, I. Suchara, Analytica Chimica Acta, 2006, 576, 163. 7. H. Altundag, M. Tuzen, Food and Chemical Toxicology, 2011, 49, 2800. 8. A.A. Momen, G.A. Zachariadis, A.N. Anthemidis, J.A. Stratis, Microchimica Acta, 2008, 160, 397. 9. M. Blander, Calculations of the Influence of Additives on Coal Combustion Deposits, Argonne National Laboratory, 2011, 315. 10. K. L. Laban, B. P. Atkin, The determination of minor and trace element associations in coal using a sequential microwave digestion procedure“, Journal of Coal Geology, 1999, 41: 351-369. 11. EIA, World Energy Projections Plus, 2009. 12. Fossil fuel, http://www.worldcoal.org/coal/where-is-coal-found/, (01.08.2014.). 13. Carbon emissions, International Energy Annual 2006, (01.08.2014.). 14. J. F. Da Silva, R. J. P. Williams. The biological chemistry of the elements: the inorganic chemistry of life: Oxford University Press, USA; 2001.
