Abstract
The comprehensive quantifying of uncertainty for the determination of caffeine in coffee is given according to the EURACHEM/CITAC Guide. The cause–effect diagram is very useful for the identification of the sources of uncertainty and the relationship between them. In this case the uncertainty caused by the pipette, the stock solution and the calibration curve are the three main sources. Concerning the concentration of the stock solution the purity of the caffeine was most important. The combined uncertainty showed that none of the three parts (stock solution, pipette, calibration curve) can be neglected. The expanded uncertainty (coverage factor k=2) is about 5.4%.
Similar content being viewed by others
References
Wenclawiak BW, Koch M, Hadjicostas E (eds) (2004) Quality Assurance in Analytical Chemistry. Springer, Berlin Heidelberg New York
Guide to the Expression of Uncertainty in Measurement, “GUM”, BIMP, ISBN 9267101889, (1995)
EURACHEM/CITAC Guide: Quantifying Uncertainty in Analytical Measurement, 2nd Edition, (2000) http://www.eurachem.ul.pt/guides/QUAM2000-1.pdf
Danzer K, Hobert H, Fischbacher C, Jagemann KU (2001) Chemometrik, Springer, Berlin Heidelberg New York
DIN 32645, Beuth Verlag, Berlin
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kolb, M., Hippich, S. Uncertainty in chemical analysis for the example of determination of caffeine in coffee. Accred Qual Assur 10, 214–218 (2005). https://doi.org/10.1007/s00769-005-0912-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00769-005-0912-8