Extraction of a quality assurance sediment sample for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F)

An experimental design for two variables at three and four levels was used to investigate the Soxhlet extraction of polychlorinated dibenzo-p-dioxins/ dibenzofurans (PCDD/F) from a quality assurance sediment. The first variable was the solvent: toluene/methanol, toluene (both Soxhlet) and toluene in...

Full description

Saved in:
Bibliographic Details
Published inFresenius' journal of analytical chemistry Vol. 361; no. 8; pp. 811 - 816
Main Authors KJELLER, L.-O, RAPPE, C
Format Journal Article
LanguageEnglish
Published Berlin Springer 28.08.1998
Subjects
Analytical chemistry
Chemistry
Exact sciences and technology
General, instrumentation
Quality assurance
Soxhlet extraction
Chemical analysis
Dioxin derivatives
pH
Benzofuran derivatives
Sediments
Supercritical fluid extraction
Online AccessGet full text

Cover

More Information
Summary:An experimental design for two variables at three and four levels was used to investigate the Soxhlet extraction of polychlorinated dibenzo-p-dioxins/ dibenzofurans (PCDD/F) from a quality assurance sediment. The first variable was the solvent: toluene/methanol, toluene (both Soxhlet) and toluene in Soxhlet-Dean-Stark equipment. The second variable were four different bulks: silica, sulfuric acid treated silica, sodium carbonate and no bulk. Extractions with toluene/methanol and sulfuric acid provided only a small contribution to the overall extraction efficiency. Toluene/methanol preferably improved the extraction of PCDD, and the sulfuric acid improved the PCDF extraction. This was likely to reflect improved extraction efficiency of substructures in the sediment as pulp effluent remains (fiber) and fly-ash particulate. A previously found PCDD formation in extractions using toluene/methanol in presence of sodium carbonate was reproduced. A designed supercritical fluid extraction (SFE) experiment was also accomplished, however even under the best used conditions some PCDD/F were retained on the particulate compared to Soxhlet extraction. Variations in extraction efficiency in Soxhlet and SFE indicated that different subfractions of PCDD/F are connected to the matrix with different mechanisms, thus indicating that different PCDD/F fractions had different abilities to equilibrate also in the real environment.
Bibliography:ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ISSN:0937-0633
1432-1130
DOI:10.1007/s002160051020