Change search
ReferencesLink to record
Permanent link

Direct link
Uncertainty of Blank Correction in Isotope Ratio Measurement
Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-90183 Umeå , Sweden.
2013 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 85, no 11, 5326-5329 p.Article in journal (Refereed) Published
Abstract [en]

Blank correction for isotope ratio measurement on small amounts of substances is often limited by presence of a blank, with an apparent isotopic composition different from that of the sample. For isotope ratios, blank correction is commonly performed either by the regression method, which works without the need for estimation of the blank, or by the subtraction method. With the subtraction method, estimation of the amount and isotope delta of the blank is required, and these estimates could be obtained either by direct, semi-indirect, or indirect measurement. Previously given expressions for the standard uncertainties of indirectly measured blank amounts and blank isotope deltas did not account for covariance between input quantities. In the present work, a previously published data set was re-evaluated, with covariance terms properly included in the calculation of uncertainties. It was shown that covariance effects may yield a significant reduction in uncertainty estimates, both for blank quantities and for blank corrected results. For series measurements on a standard material, it was also shown that the distribution of individual corrected isotope delta values around the average value was approximately normal, with its standard deviation equal to the estimated standard uncertainty of the corrected values. In most cases, it was observed that the regression and subtraction methods yield approximately the same blank corrected average values and uncertainties, regardless of method selected for estimation of blank quantities.

Place, publisher, year, edition, pages
2013. Vol. 85, no 11, 5326-5329 p.
National Category
Analytical Chemistry
URN: urn:nbn:se:umu:diva-76782DOI: 10.1021/ac4003968ISI: 000320096900008OAI: diva2:637164
Available from: 2013-07-16 Created: 2013-07-15 Last updated: 2016-06-08Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Ohlsson, K. E. Anders
In the same journal
Analytical Chemistry
Analytical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 47 hits
ReferencesLink to record
Permanent link

Direct link