Comparative studies of the static and dynamic headspace extraction of saturated short chain aldehydes from cellulose-based packaging materials.
Aldehydes in cellulose-based materials such as cardboard are derived from lipid degradation. Depending on the production- and storage conditions of the cardboard, the aldehyde content changes. Owing to their sensorial properties, accurate control of their content is obligatory. The cardboard usually exhibits strong and even varying matrix effects and considerable inhomogeneity. The comparability of results of analysis after static and dynamic headspace extraction of short chained saturated aldehydes from cellulose-based matrices was studied. In the case of the static extraction technique, special attention was given to the establishment of the headspace equilibrium, which could be reached by the addition of water as a displacer. For dynamic headspace extraction, the volatiles were purged from the matrix by an inert gas and enriched on an adsorbent trap. In theory, the extraction yield should be 100%. Since there are no certified reference materials for verification of the extraction efficiency available, confirmation was achieved by determining the total amount of analytes in the sample by means of multiple headspace extraction.In comparison to the static operation mode, the major drawbacks of the dynamic technique were found to be based on a more complex parameter string and on limitations to the extractable sample quantities, which may result in enhanced uncertainty of the measurements. Nevertheless, the results of analysis pointed out that both headspace extraction techniques are suitable for the determination of volatile aldehydes from cellulose-based materials.
Wenzl
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Institute for Analytical Chemistry, Micro- and Radiochemistry, Technical University of Graz, Technikerstrasse 4, 8010 Graz, Austria. wenzl@analytchem.tu-graz.ac.at
Lankmayr
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EP