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| Titel |
On the quantification of atmospheric carbonate carbon by thermal/optical analysis protocols |
| VerfasserIn |
A. Karanasiou, E. Diapouli, F. Cavalli, K. Eleftheriadis, M. Viana, A. Alastuey, X. Querol, C. Reche |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 4, no. 11 ; Nr. 4, no. 11 (2011-11-10), S.2409-2419 |
| Datensatznummer |
250002132
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| Publikation (Nr.) |
 copernicus.org/amt-4-2409-2011.pdf |
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| Zusammenfassung |
| The objective of this work was to study the possibility of identifying and
quantifying atmospheric carbonate carbon (CC) by thermal-optical
analysis. Three different temperature protocols, two modified
NIOSH-like protocols (RT-QUARTZ-840 and RT-QUARTZ-700), and the EUSAAR_2
protocol were tested on filter samples containing known amounts of CC with
the semi-continuous Sunset analyzer. Carbonate was quantified by the manual
integration of the sharp peak appeared at the maximum temperature step of
the inert mode. High recoveries of CC were achieved by all the thermal
protocols. Using the EUSAAR_2 thermal protocol, more than 95% of CC
evolved as OC during the maximum temperature step in inert atmosphere for CC
amounts up to 56 μg. Using the RT-QUARTZ-840 protocol specifically
developed for on-line analyses, CC completely evolves as OC during the
maximum temperature step in the inert node, regardless of the CC
concentration. However, the quantification of CC by the RT-QUARTZ-840
protocol suitable for the semi-continuous analyzer implies a high level of
uncertainty (manual integration, residual contribution of organic carbon).
Therefore, it is advisable to determine CC with an independent method (e.g.
by acidic decomposition of CO32- and subsequent detection of
CO2) when other sample aliquots are available. The comparison of the
peak integration method with the direct determination of the CC sample
content by acidic CO2 release showed that the peak integration method
provides always higher CC concentrations of about 33%. Nevertheless, the
determination of CC with the RT-QUARTZ-840 protocol may be considered in
cases where on line monitoring instruments are used and for areas where CC
concentrations are expected to be significant e.g. Southern European
countries. This case study suggests that users of the semi continuous Sunset
analyzer can manually integrate the sharp peak (if present) at the maximum
temperature step of the He mode (between 128–130 and 160–165 s when using the
RT-QUARTZ-840 protocol) and calculate the CC concentration though with a
rather high error. |
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