A New Method for Low‐Temperature Decomposition of Chromites and Dichromium Trioxide using Bromic Acid Evaluated by Chromium Isotope Measurements |
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Authors: | Vladislav Chrastný Jan Rohovec Eva Čadková Jan Pašava Juraj Farkaš Martin Novák |
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Affiliation: | 1. Czech Geological Survey, , 152 00 Prague 5, Czech Republic;2. Institute of Geology AS CR, v. v. i., , 165 00 Prague 6, Czech Republic |
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Abstract: | In recent years, routine application of the stable isotope determination of chromium (Cr) in environmental and health protection research has led to the search for simpler chromite decomposition techniques. As the range of Cr isotope abundance ratios in nature is very narrow, conventional chromite decomposition techniques are no longer suitable, due to the relatively high risk of contamination during laboratory procedures. We have developed a protocol for the decomposition of chromites based on oxidation by bromic acid at room temperature. The procedure takes 15 d and requires two doses of bromic acid during the reaction period (day 1 and 8), due to the limited stability of the reagent. Chromium extracted by alkaline oxidative fusion and by bromic acid decomposition yielded statistically indistinguishable δ53Cr values, measured by multi‐collector inductively coupled plasma‐mass spectrometry following addition of a 50Cr‐54Cr double‐spike. |
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Keywords: | chromites dichromium trioxide decomposition chromium isotopes bromic acid chromites trioxyde de dichrome dé composition isotopes du chrome acide bromique |
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