Details
| Original language | English |
|---|---|
| Pages (from-to) | 583-591 |
| Number of pages | 9 |
| Journal | Rapid Communications in Mass Spectrometry |
| Volume | 26 |
| Issue number | 6 |
| Publication status | Published - 10 Feb 2012 |
| Externally published | Yes |
Abstract
Polymerization in hexavalent uranium solutions was measured by electrospray ionization time-of-flight mass spectrometry in three different acidic media at pH values from 3 to 5.3 in order to detect all hydrolysis species present in solution. The aqueous solutions were directly measured without further dilution in organic solvents. At high uranyl concentrations ([U(VI)] = 10 -3 M) artifacts were observed due to the presence of more than one solution species per formed microdroplet. Those artifacts were composed of ions and neutral species being present in the same droplet. However, by analyzing the detected species carefully, the origin of the artifacts could be traced back to the physically meaningful species. Still, only general trends of the hydrolysis behavior can be deduced from the measurements at [U(VI)] = 1 · 10 -3 M. The solutions at [U(VI)] = 5 · 10 -5 M did not show any comparable artifact formation. The detected species distributions resemble the expected trends calculated from the equilibrium constants published in the Nuclear Energy Agency Thermodynamic Database (NEA-TDB). The neutral (UO 2)(CO 3) 0 species present in solution causes, if located in the same microdroplet as a charged species, the apparent formation of dimeric and trimeric ternary hydroxo carbonate complexes at pH 5.3. As the uncharged species is not repelled from the ionic species, it might remain in the same droplet during the droplet fission process. By dividing those detected species into the uncharged (UO 2)(CO 3) 0 and a second ionic species, the relative abundances of the solution species can be corrected, leading to a good agreement with the predictions of the published equilibrium constants. In addition to the well-known trimer, we report the direct mass spectrometric detection of the dimeric (UO2)2(OH)22+ species.
ASJC Scopus subject areas
- Chemistry(all)
- Analytical Chemistry
- Chemistry(all)
- Spectroscopy
- Chemistry(all)
- Organic Chemistry
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In: Rapid Communications in Mass Spectrometry, Vol. 26, No. 6, 10.02.2012, p. 583-591.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - On the polymerization of hexavalent uranium. An electrospray mass spectrometry study
AU - Steppert, Michael
AU - Walther, Clemens
AU - Fuss, Markus
AU - Büchner, Stefanie
PY - 2012/2/10
Y1 - 2012/2/10
N2 - Polymerization in hexavalent uranium solutions was measured by electrospray ionization time-of-flight mass spectrometry in three different acidic media at pH values from 3 to 5.3 in order to detect all hydrolysis species present in solution. The aqueous solutions were directly measured without further dilution in organic solvents. At high uranyl concentrations ([U(VI)] = 10 -3 M) artifacts were observed due to the presence of more than one solution species per formed microdroplet. Those artifacts were composed of ions and neutral species being present in the same droplet. However, by analyzing the detected species carefully, the origin of the artifacts could be traced back to the physically meaningful species. Still, only general trends of the hydrolysis behavior can be deduced from the measurements at [U(VI)] = 1 · 10 -3 M. The solutions at [U(VI)] = 5 · 10 -5 M did not show any comparable artifact formation. The detected species distributions resemble the expected trends calculated from the equilibrium constants published in the Nuclear Energy Agency Thermodynamic Database (NEA-TDB). The neutral (UO 2)(CO 3) 0 species present in solution causes, if located in the same microdroplet as a charged species, the apparent formation of dimeric and trimeric ternary hydroxo carbonate complexes at pH 5.3. As the uncharged species is not repelled from the ionic species, it might remain in the same droplet during the droplet fission process. By dividing those detected species into the uncharged (UO 2)(CO 3) 0 and a second ionic species, the relative abundances of the solution species can be corrected, leading to a good agreement with the predictions of the published equilibrium constants. In addition to the well-known trimer, we report the direct mass spectrometric detection of the dimeric (UO2)2(OH)22+ species.
AB - Polymerization in hexavalent uranium solutions was measured by electrospray ionization time-of-flight mass spectrometry in three different acidic media at pH values from 3 to 5.3 in order to detect all hydrolysis species present in solution. The aqueous solutions were directly measured without further dilution in organic solvents. At high uranyl concentrations ([U(VI)] = 10 -3 M) artifacts were observed due to the presence of more than one solution species per formed microdroplet. Those artifacts were composed of ions and neutral species being present in the same droplet. However, by analyzing the detected species carefully, the origin of the artifacts could be traced back to the physically meaningful species. Still, only general trends of the hydrolysis behavior can be deduced from the measurements at [U(VI)] = 1 · 10 -3 M. The solutions at [U(VI)] = 5 · 10 -5 M did not show any comparable artifact formation. The detected species distributions resemble the expected trends calculated from the equilibrium constants published in the Nuclear Energy Agency Thermodynamic Database (NEA-TDB). The neutral (UO 2)(CO 3) 0 species present in solution causes, if located in the same microdroplet as a charged species, the apparent formation of dimeric and trimeric ternary hydroxo carbonate complexes at pH 5.3. As the uncharged species is not repelled from the ionic species, it might remain in the same droplet during the droplet fission process. By dividing those detected species into the uncharged (UO 2)(CO 3) 0 and a second ionic species, the relative abundances of the solution species can be corrected, leading to a good agreement with the predictions of the published equilibrium constants. In addition to the well-known trimer, we report the direct mass spectrometric detection of the dimeric (UO2)2(OH)22+ species.
UR - http://www.scopus.com/inward/record.url?scp=84857092798&partnerID=8YFLogxK
U2 - 10.1002/rcm.6128
DO - 10.1002/rcm.6128
M3 - Article
AN - SCOPUS:84857092798
VL - 26
SP - 583
EP - 591
JO - Rapid Communications in Mass Spectrometry
JF - Rapid Communications in Mass Spectrometry
SN - 0951-4198
IS - 6
ER -