An automated extraction apparatus (Dionex ASE200
Accelerated Solvent Extractor) is used to extract
various organic hydrocarbons from pre-dried sediment.
The extractions are performed using hexane inside
stainless-steel extraction cells held at elevated
temperature and solvent pressure.
This method of extraction minimizes the use of solvent
and decreases the extraction time when compared
to conventional Soxhlet extractions.
The extracts dissolved in the hot solvent are transferred
from the heated extraction cells to glass collection
vials. Pre-cleaned, activated copper is added to
each collection vial in order to minimize matrix
interference.
Extracts are concentrated to a final volume of
8-ml using an evaporative solvent reduction apparatus
(Zymark TurboVap II). Final extracts are submitted
for hydrocarbon analysis by Total Scanning Fluorescence
(TSF) and Gas Chromatography Flame Ionization Detection
(GC/FID).
Before processing any samples, all parts of the
equipment are demonstrated to be interference-free.
This is accomplished through the analysis of method
blanks.
Oil spikes (extractions of a known amount of diluted
crude oil) are analyzed with every sample-set in
order to demonstrate the reproducibility of the
extraction procedure.
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ASE
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Zymark
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